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-rw-r--r--kernel/audit_tree.c19
-rw-r--r--kernel/debug/kdb/kdb_debugger.c4
-rw-r--r--kernel/debug/kdb/kdb_io.c11
-rw-r--r--kernel/debug/kdb/kdb_main.c15
-rw-r--r--kernel/events/callchain.c9
-rw-r--r--kernel/events/core.c94
-rw-r--r--kernel/events/hw_breakpoint.c11
-rw-r--r--kernel/events/internal.h3
-rw-r--r--kernel/fork.c4
-rw-r--r--kernel/futex.c17
-rw-r--r--kernel/irq/manage.c15
-rw-r--r--kernel/pid_namespace.c6
-rw-r--r--kernel/power/suspend.c3
-rw-r--r--kernel/printk.c2
-rw-r--r--kernel/sched/core.c112
-rw-r--r--kernel/sched/cpupri.c10
-rw-r--r--kernel/sched/fair.c77
-rw-r--r--kernel/sched/rt.c14
-rw-r--r--kernel/sched/sched.h9
-rw-r--r--kernel/sched/stop_task.c22
-rw-r--r--kernel/task_work.c1
-rw-r--r--kernel/time/jiffies.c2
-rw-r--r--kernel/time/ntp.c2
-rw-r--r--kernel/time/tick-sched.c1
-rw-r--r--kernel/time/timekeeping.c455
-rw-r--r--kernel/timer.c9
-rw-r--r--kernel/trace/trace_event_perf.c2
-rw-r--r--kernel/trace/trace_kprobe.c6
-rw-r--r--kernel/trace/trace_syscalls.c8
-rw-r--r--kernel/trace/trace_uprobe.c2
-rw-r--r--kernel/watchdog.c21
-rw-r--r--kernel/workqueue.c147
32 files changed, 647 insertions, 466 deletions
diff --git a/kernel/audit_tree.c b/kernel/audit_tree.c
index 3a5ca582ba1e..ed206fd88cca 100644
--- a/kernel/audit_tree.c
+++ b/kernel/audit_tree.c
@@ -250,7 +250,6 @@ static void untag_chunk(struct node *p)
spin_unlock(&hash_lock);
spin_unlock(&entry->lock);
fsnotify_destroy_mark(entry);
- fsnotify_put_mark(entry);
goto out;
}
@@ -259,7 +258,7 @@ static void untag_chunk(struct node *p)
fsnotify_duplicate_mark(&new->mark, entry);
if (fsnotify_add_mark(&new->mark, new->mark.group, new->mark.i.inode, NULL, 1)) {
- free_chunk(new);
+ fsnotify_put_mark(&new->mark);
goto Fallback;
}
@@ -293,7 +292,7 @@ static void untag_chunk(struct node *p)
spin_unlock(&hash_lock);
spin_unlock(&entry->lock);
fsnotify_destroy_mark(entry);
- fsnotify_put_mark(entry);
+ fsnotify_put_mark(&new->mark); /* drop initial reference */
goto out;
Fallback:
@@ -322,7 +321,7 @@ static int create_chunk(struct inode *inode, struct audit_tree *tree)
entry = &chunk->mark;
if (fsnotify_add_mark(entry, audit_tree_group, inode, NULL, 0)) {
- free_chunk(chunk);
+ fsnotify_put_mark(entry);
return -ENOSPC;
}
@@ -347,6 +346,7 @@ static int create_chunk(struct inode *inode, struct audit_tree *tree)
insert_hash(chunk);
spin_unlock(&hash_lock);
spin_unlock(&entry->lock);
+ fsnotify_put_mark(entry); /* drop initial reference */
return 0;
}
@@ -396,7 +396,7 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
fsnotify_duplicate_mark(chunk_entry, old_entry);
if (fsnotify_add_mark(chunk_entry, chunk_entry->group, chunk_entry->i.inode, NULL, 1)) {
spin_unlock(&old_entry->lock);
- free_chunk(chunk);
+ fsnotify_put_mark(chunk_entry);
fsnotify_put_mark(old_entry);
return -ENOSPC;
}
@@ -444,8 +444,8 @@ static int tag_chunk(struct inode *inode, struct audit_tree *tree)
spin_unlock(&chunk_entry->lock);
spin_unlock(&old_entry->lock);
fsnotify_destroy_mark(old_entry);
+ fsnotify_put_mark(chunk_entry); /* drop initial reference */
fsnotify_put_mark(old_entry); /* pair to fsnotify_find mark_entry */
- fsnotify_put_mark(old_entry); /* and kill it */
return 0;
}
@@ -916,7 +916,12 @@ static void audit_tree_freeing_mark(struct fsnotify_mark *entry, struct fsnotify
struct audit_chunk *chunk = container_of(entry, struct audit_chunk, mark);
evict_chunk(chunk);
- fsnotify_put_mark(entry);
+
+ /*
+ * We are guaranteed to have at least one reference to the mark from
+ * either the inode or the caller of fsnotify_destroy_mark().
+ */
+ BUG_ON(atomic_read(&entry->refcnt) < 1);
}
static bool audit_tree_send_event(struct fsnotify_group *group, struct inode *inode,
diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c
index 8b68ce78ff17..be7b33b73d30 100644
--- a/kernel/debug/kdb/kdb_debugger.c
+++ b/kernel/debug/kdb/kdb_debugger.c
@@ -12,6 +12,7 @@
#include <linux/kdb.h>
#include <linux/kdebug.h>
#include <linux/export.h>
+#include <linux/hardirq.h>
#include "kdb_private.h"
#include "../debug_core.h"
@@ -52,6 +53,9 @@ int kdb_stub(struct kgdb_state *ks)
if (atomic_read(&kgdb_setting_breakpoint))
reason = KDB_REASON_KEYBOARD;
+ if (in_nmi())
+ reason = KDB_REASON_NMI;
+
for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) {
if ((bp->bp_enabled) && (bp->bp_addr == addr)) {
reason = KDB_REASON_BREAK;
diff --git a/kernel/debug/kdb/kdb_io.c b/kernel/debug/kdb/kdb_io.c
index bb9520f0f6ff..0a69d2adc4f3 100644
--- a/kernel/debug/kdb/kdb_io.c
+++ b/kernel/debug/kdb/kdb_io.c
@@ -715,9 +715,6 @@ kdb_printit:
/* check for having reached the LINES number of printed lines */
if (kdb_nextline == linecount) {
char buf1[16] = "";
-#if defined(CONFIG_SMP)
- char buf2[32];
-#endif
/* Watch out for recursion here. Any routine that calls
* kdb_printf will come back through here. And kdb_read
@@ -732,14 +729,6 @@ kdb_printit:
if (moreprompt == NULL)
moreprompt = "more> ";
-#if defined(CONFIG_SMP)
- if (strchr(moreprompt, '%')) {
- sprintf(buf2, moreprompt, get_cpu());
- put_cpu();
- moreprompt = buf2;
- }
-#endif
-
kdb_input_flush();
c = console_drivers;
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 1f91413edb87..31df1706b9a9 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -139,11 +139,10 @@ static const int __nkdb_err = sizeof(kdbmsgs) / sizeof(kdbmsg_t);
static char *__env[] = {
#if defined(CONFIG_SMP)
"PROMPT=[%d]kdb> ",
- "MOREPROMPT=[%d]more> ",
#else
"PROMPT=kdb> ",
- "MOREPROMPT=more> ",
#endif
+ "MOREPROMPT=more> ",
"RADIX=16",
"MDCOUNT=8", /* lines of md output */
KDB_PLATFORM_ENV,
@@ -1236,18 +1235,6 @@ static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
*cmdbuf = '\0';
*(cmd_hist[cmd_head]) = '\0';
- if (KDB_FLAG(ONLY_DO_DUMP)) {
- /* kdb is off but a catastrophic error requires a dump.
- * Take the dump and reboot.
- * Turn on logging so the kdb output appears in the log
- * buffer in the dump.
- */
- const char *setargs[] = { "set", "LOGGING", "1" };
- kdb_set(2, setargs);
- kdb_reboot(0, NULL);
- /*NOTREACHED*/
- }
-
do_full_getstr:
#if defined(CONFIG_SMP)
snprintf(kdb_prompt_str, CMD_BUFLEN, kdbgetenv("PROMPT"),
diff --git a/kernel/events/callchain.c b/kernel/events/callchain.c
index 6581a040f399..98d4597f43d6 100644
--- a/kernel/events/callchain.c
+++ b/kernel/events/callchain.c
@@ -153,7 +153,8 @@ put_callchain_entry(int rctx)
put_recursion_context(__get_cpu_var(callchain_recursion), rctx);
}
-struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
+struct perf_callchain_entry *
+perf_callchain(struct perf_event *event, struct pt_regs *regs)
{
int rctx;
struct perf_callchain_entry *entry;
@@ -178,6 +179,12 @@ struct perf_callchain_entry *perf_callchain(struct pt_regs *regs)
}
if (regs) {
+ /*
+ * Disallow cross-task user callchains.
+ */
+ if (event->ctx->task && event->ctx->task != current)
+ goto exit_put;
+
perf_callchain_store(entry, PERF_CONTEXT_USER);
perf_callchain_user(entry, regs);
}
diff --git a/kernel/events/core.c b/kernel/events/core.c
index f1cf0edeb39a..7fee567153f0 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -1253,7 +1253,7 @@ retry:
/*
* Cross CPU call to disable a performance event
*/
-static int __perf_event_disable(void *info)
+int __perf_event_disable(void *info)
{
struct perf_event *event = info;
struct perf_event_context *ctx = event->ctx;
@@ -2935,12 +2935,12 @@ EXPORT_SYMBOL_GPL(perf_event_release_kernel);
/*
* Called when the last reference to the file is gone.
*/
-static int perf_release(struct inode *inode, struct file *file)
+static void put_event(struct perf_event *event)
{
- struct perf_event *event = file->private_data;
struct task_struct *owner;
- file->private_data = NULL;
+ if (!atomic_long_dec_and_test(&event->refcount))
+ return;
rcu_read_lock();
owner = ACCESS_ONCE(event->owner);
@@ -2975,7 +2975,13 @@ static int perf_release(struct inode *inode, struct file *file)
put_task_struct(owner);
}
- return perf_event_release_kernel(event);
+ perf_event_release_kernel(event);
+}
+
+static int perf_release(struct inode *inode, struct file *file)
+{
+ put_event(file->private_data);
+ return 0;
}
u64 perf_event_read_value(struct perf_event *event, u64 *enabled, u64 *running)
@@ -3227,7 +3233,7 @@ unlock:
static const struct file_operations perf_fops;
-static struct perf_event *perf_fget_light(int fd, int *fput_needed)
+static struct file *perf_fget_light(int fd, int *fput_needed)
{
struct file *file;
@@ -3241,7 +3247,7 @@ static struct perf_event *perf_fget_light(int fd, int *fput_needed)
return ERR_PTR(-EBADF);
}
- return file->private_data;
+ return file;
}
static int perf_event_set_output(struct perf_event *event,
@@ -3273,19 +3279,21 @@ static long perf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case PERF_EVENT_IOC_SET_OUTPUT:
{
+ struct file *output_file = NULL;
struct perf_event *output_event = NULL;
int fput_needed = 0;
int ret;
if (arg != -1) {
- output_event = perf_fget_light(arg, &fput_needed);
- if (IS_ERR(output_event))
- return PTR_ERR(output_event);
+ output_file = perf_fget_light(arg, &fput_needed);
+ if (IS_ERR(output_file))
+ return PTR_ERR(output_file);
+ output_event = output_file->private_data;
}
ret = perf_event_set_output(event, output_event);
if (output_event)
- fput_light(output_event->filp, fput_needed);
+ fput_light(output_file, fput_needed);
return ret;
}
@@ -4039,7 +4047,7 @@ void perf_prepare_sample(struct perf_event_header *header,
if (sample_type & PERF_SAMPLE_CALLCHAIN) {
int size = 1;
- data->callchain = perf_callchain(regs);
+ data->callchain = perf_callchain(event, regs);
if (data->callchain)
size += data->callchain->nr;
@@ -5209,7 +5217,8 @@ static int perf_tp_event_match(struct perf_event *event,
}
void perf_tp_event(u64 addr, u64 count, void *record, int entry_size,
- struct pt_regs *regs, struct hlist_head *head, int rctx)
+ struct pt_regs *regs, struct hlist_head *head, int rctx,
+ struct task_struct *task)
{
struct perf_sample_data data;
struct perf_event *event;
@@ -5228,6 +5237,31 @@ void perf_tp_event(u64 addr, u64 count, void *record, int entry_size,
perf_swevent_event(event, count, &data, regs);
}
+ /*
+ * If we got specified a target task, also iterate its context and
+ * deliver this event there too.
+ */
+ if (task && task != current) {
+ struct perf_event_context *ctx;
+ struct trace_entry *entry = record;
+
+ rcu_read_lock();
+ ctx = rcu_dereference(task->perf_event_ctxp[perf_sw_context]);
+ if (!ctx)
+ goto unlock;
+
+ list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
+ if (event->attr.type != PERF_TYPE_TRACEPOINT)
+ continue;
+ if (event->attr.config != entry->type)
+ continue;
+ if (perf_tp_event_match(event, &data, regs))
+ perf_swevent_event(event, count, &data, regs);
+ }
+unlock:
+ rcu_read_unlock();
+ }
+
perf_swevent_put_recursion_context(rctx);
}
EXPORT_SYMBOL_GPL(perf_tp_event);
@@ -5924,6 +5958,7 @@ perf_event_alloc(struct perf_event_attr *attr, int cpu,
mutex_init(&event->mmap_mutex);
+ atomic_long_set(&event->refcount, 1);
event->cpu = cpu;
event->attr = *attr;
event->group_leader = group_leader;
@@ -6234,12 +6269,12 @@ SYSCALL_DEFINE5(perf_event_open,
return event_fd;
if (group_fd != -1) {
- group_leader = perf_fget_light(group_fd, &fput_needed);
- if (IS_ERR(group_leader)) {
- err = PTR_ERR(group_leader);
+ group_file = perf_fget_light(group_fd, &fput_needed);
+ if (IS_ERR(group_file)) {
+ err = PTR_ERR(group_file);
goto err_fd;
}
- group_file = group_leader->filp;
+ group_leader = group_file->private_data;
if (flags & PERF_FLAG_FD_OUTPUT)
output_event = group_leader;
if (flags & PERF_FLAG_FD_NO_GROUP)
@@ -6376,7 +6411,6 @@ SYSCALL_DEFINE5(perf_event_open,
put_ctx(gctx);
}
- event->filp = event_file;
WARN_ON_ONCE(ctx->parent_ctx);
mutex_lock(&ctx->mutex);
@@ -6470,7 +6504,6 @@ perf_event_create_kernel_counter(struct perf_event_attr *attr, int cpu,
goto err_free;
}
- event->filp = NULL;
WARN_ON_ONCE(ctx->parent_ctx);
mutex_lock(&ctx->mutex);
perf_install_in_context(ctx, event, cpu);
@@ -6552,7 +6585,7 @@ static void sync_child_event(struct perf_event *child_event,
* Release the parent event, if this was the last
* reference to it.
*/
- fput(parent_event->filp);
+ put_event(parent_event);
}
static void
@@ -6628,9 +6661,8 @@ static void perf_event_exit_task_context(struct task_struct *child, int ctxn)
*
* __perf_event_exit_task()
* sync_child_event()
- * fput(parent_event->filp)
- * perf_release()
- * mutex_lock(&ctx->mutex)
+ * put_event()
+ * mutex_lock(&ctx->mutex)
*
* But since its the parent context it won't be the same instance.
*/
@@ -6698,7 +6730,7 @@ static void perf_free_event(struct perf_event *event,
list_del_init(&event->child_list);
mutex_unlock(&parent->child_mutex);
- fput(parent->filp);
+ put_event(parent);
perf_group_detach(event);
list_del_event(event, ctx);
@@ -6778,6 +6810,12 @@ inherit_event(struct perf_event *parent_event,
NULL, NULL);
if (IS_ERR(child_event))
return child_event;
+
+ if (!atomic_long_inc_not_zero(&parent_event->refcount)) {
+ free_event(child_event);
+ return NULL;
+ }
+
get_ctx(child_ctx);
/*
@@ -6819,14 +6857,6 @@ inherit_event(struct perf_event *parent_event,
raw_spin_unlock_irqrestore(&child_ctx->lock, flags);
/*
- * Get a reference to the parent filp - we will fput it
- * when the child event exits. This is safe to do because
- * we are in the parent and we know that the filp still
- * exists and has a nonzero count:
- */
- atomic_long_inc(&parent_event->filp->f_count);
-
- /*
* Link this into the parent event's child list
*/
WARN_ON_ONCE(parent_event->ctx->parent_ctx);
diff --git a/kernel/events/hw_breakpoint.c b/kernel/events/hw_breakpoint.c
index bb38c4d3ee12..9a7b487c6fe2 100644
--- a/kernel/events/hw_breakpoint.c
+++ b/kernel/events/hw_breakpoint.c
@@ -453,7 +453,16 @@ int modify_user_hw_breakpoint(struct perf_event *bp, struct perf_event_attr *att
int old_type = bp->attr.bp_type;
int err = 0;
- perf_event_disable(bp);
+ /*
+ * modify_user_hw_breakpoint can be invoked with IRQs disabled and hence it
+ * will not be possible to raise IPIs that invoke __perf_event_disable.
+ * So call the function directly after making sure we are targeting the
+ * current task.
+ */
+ if (irqs_disabled() && bp->ctx && bp->ctx->task == current)
+ __perf_event_disable(bp);
+ else
+ perf_event_disable(bp);
bp->attr.bp_addr = attr->bp_addr;
bp->attr.bp_type = attr->bp_type;
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index b0b107f90afc..a096c19f2c2a 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -101,7 +101,8 @@ __output_copy(struct perf_output_handle *handle,
}
/* Callchain handling */
-extern struct perf_callchain_entry *perf_callchain(struct pt_regs *regs);
+extern struct perf_callchain_entry *
+perf_callchain(struct perf_event *event, struct pt_regs *regs);
extern int get_callchain_buffers(void);
extern void put_callchain_buffers(void);
diff --git a/kernel/fork.c b/kernel/fork.c
index 3bd2280d79f6..2c8857e12855 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -455,8 +455,8 @@ static int dup_mmap(struct mm_struct *mm, struct mm_struct *oldmm)
if (retval)
goto out;
- if (file && uprobe_mmap(tmp))
- goto out;
+ if (file)
+ uprobe_mmap(tmp);
}
/* a new mm has just been created */
arch_dup_mmap(oldmm, mm);
diff --git a/kernel/futex.c b/kernel/futex.c
index e2b0fb9a0b3b..3717e7b306e0 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2231,11 +2231,11 @@ int handle_early_requeue_pi_wakeup(struct futex_hash_bucket *hb,
* @uaddr2: the pi futex we will take prior to returning to user-space
*
* The caller will wait on uaddr and will be requeued by futex_requeue() to
- * uaddr2 which must be PI aware. Normal wakeup will wake on uaddr2 and
- * complete the acquisition of the rt_mutex prior to returning to userspace.
- * This ensures the rt_mutex maintains an owner when it has waiters; without
- * one, the pi logic wouldn't know which task to boost/deboost, if there was a
- * need to.
+ * uaddr2 which must be PI aware and unique from uaddr. Normal wakeup will wake
+ * on uaddr2 and complete the acquisition of the rt_mutex prior to returning to
+ * userspace. This ensures the rt_mutex maintains an owner when it has waiters;
+ * without one, the pi logic would not know which task to boost/deboost, if
+ * there was a need to.
*
* We call schedule in futex_wait_queue_me() when we enqueue and return there
* via the following:
@@ -2272,6 +2272,9 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
struct futex_q q = futex_q_init;
int res, ret;
+ if (uaddr == uaddr2)
+ return -EINVAL;
+
if (!bitset)
return -EINVAL;
@@ -2343,7 +2346,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
* signal. futex_unlock_pi() will not destroy the lock_ptr nor
* the pi_state.
*/
- WARN_ON(!&q.pi_state);
+ WARN_ON(!q.pi_state);
pi_mutex = &q.pi_state->pi_mutex;
ret = rt_mutex_finish_proxy_lock(pi_mutex, to, &rt_waiter, 1);
debug_rt_mutex_free_waiter(&rt_waiter);
@@ -2370,7 +2373,7 @@ static int futex_wait_requeue_pi(u32 __user *uaddr, unsigned int flags,
* fault, unlock the rt_mutex and return the fault to userspace.
*/
if (ret == -EFAULT) {
- if (rt_mutex_owner(pi_mutex) == current)
+ if (pi_mutex && rt_mutex_owner(pi_mutex) == current)
rt_mutex_unlock(pi_mutex);
} else if (ret == -EINTR) {
/*
diff --git a/kernel/irq/manage.c b/kernel/irq/manage.c
index 0a8e8f059627..4c69326aa773 100644
--- a/kernel/irq/manage.c
+++ b/kernel/irq/manage.c
@@ -944,6 +944,18 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
}
/*
+ * Drivers are often written to work w/o knowledge about the
+ * underlying irq chip implementation, so a request for a
+ * threaded irq without a primary hard irq context handler
+ * requires the ONESHOT flag to be set. Some irq chips like
+ * MSI based interrupts are per se one shot safe. Check the
+ * chip flags, so we can avoid the unmask dance at the end of
+ * the threaded handler for those.
+ */
+ if (desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)
+ new->flags &= ~IRQF_ONESHOT;
+
+ /*
* The following block of code has to be executed atomically
*/
raw_spin_lock_irqsave(&desc->lock, flags);
@@ -1017,7 +1029,8 @@ __setup_irq(unsigned int irq, struct irq_desc *desc, struct irqaction *new)
*/
new->thread_mask = 1 << ffz(thread_mask);
- } else if (new->handler == irq_default_primary_handler) {
+ } else if (new->handler == irq_default_primary_handler &&
+ !(desc->irq_data.chip->flags & IRQCHIP_ONESHOT_SAFE)) {
/*
* The interrupt was requested with handler = NULL, so
* we use the default primary handler for it. But it
diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c
index b3c7fd554250..6144bab8fd8e 100644
--- a/kernel/pid_namespace.c
+++ b/kernel/pid_namespace.c
@@ -232,15 +232,19 @@ static int pid_ns_ctl_handler(struct ctl_table *table, int write,
*/
tmp.data = &current->nsproxy->pid_ns->last_pid;
- return proc_dointvec(&tmp, write, buffer, lenp, ppos);
+ return proc_dointvec_minmax(&tmp, write, buffer, lenp, ppos);
}
+extern int pid_max;
+static int zero = 0;
static struct ctl_table pid_ns_ctl_table[] = {
{
.procname = "ns_last_pid",
.maxlen = sizeof(int),
.mode = 0666, /* permissions are checked in the handler */
.proc_handler = pid_ns_ctl_handler,
+ .extra1 = &zero,
+ .extra2 = &pid_max,
},
{ }
};
diff --git a/kernel/power/suspend.c b/kernel/power/suspend.c
index 1da39ea248fd..c8b7446b27df 100644
--- a/kernel/power/suspend.c
+++ b/kernel/power/suspend.c
@@ -178,9 +178,6 @@ static int suspend_enter(suspend_state_t state, bool *wakeup)
arch_suspend_enable_irqs();
BUG_ON(irqs_disabled());
- /* Kick the lockup detector */
- lockup_detector_bootcpu_resume();
-
Enable_cpus:
enable_nonboot_cpus();
diff --git a/kernel/printk.c b/kernel/printk.c
index 6a76ab9d4476..66a2ea37b576 100644
--- a/kernel/printk.c
+++ b/kernel/printk.c
@@ -1034,6 +1034,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
struct log *msg = log_from_idx(idx);
len += msg_print_text(msg, prev, true, NULL, 0);
+ prev = msg->flags;
idx = log_next(idx);
seq++;
}
@@ -1046,6 +1047,7 @@ static int syslog_print_all(char __user *buf, int size, bool clear)
struct log *msg = log_from_idx(idx);
len -= msg_print_text(msg, prev, true, NULL, 0);
+ prev = msg->flags;
idx = log_next(idx);
seq++;
}
diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index d325c4b2dcbb..649c9f876cb1 100644
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -3142,6 +3142,20 @@ void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
# define nsecs_to_cputime(__nsecs) nsecs_to_jiffies(__nsecs)
#endif
+static cputime_t scale_utime(cputime_t utime, cputime_t rtime, cputime_t total)
+{
+ u64 temp = (__force u64) rtime;
+
+ temp *= (__force u64) utime;
+
+ if (sizeof(cputime_t) == 4)
+ temp = div_u64(temp, (__force u32) total);
+ else
+ temp = div64_u64(temp, (__force u64) total);
+
+ return (__force cputime_t) temp;
+}
+
void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
{
cputime_t rtime, utime = p->utime, total = utime + p->stime;
@@ -3151,13 +3165,9 @@ void task_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
*/
rtime = nsecs_to_cputime(p->se.sum_exec_runtime);
- if (total) {
- u64 temp = (__force u64) rtime;
-
- temp *= (__force u64) utime;
- do_div(temp, (__force u32) total);
- utime = (__force cputime_t) temp;
- } else
+ if (total)
+ utime = scale_utime(utime, rtime, total);
+ else
utime = rtime;
/*
@@ -3184,13 +3194,9 @@ void thread_group_times(struct task_struct *p, cputime_t *ut, cputime_t *st)
total = cputime.utime + cputime.stime;
rtime = nsecs_to_cputime(cputime.sum_exec_runtime);
- if (total) {
- u64 temp = (__force u64) rtime;
-
- temp *= (__force u64) cputime.utime;
- do_div(temp, (__force u32) total);
- utime = (__force cputime_t) temp;
- } else
+ if (total)
+ utime = scale_utime(cputime.utime, rtime, total);
+ else
utime = rtime;
sig->prev_utime = max(sig->prev_utime, utime);
@@ -4340,9 +4346,7 @@ recheck:
*/
if (unlikely(policy == p->policy && (!rt_policy(policy) ||
param->sched_priority == p->rt_priority))) {
-
- __task_rq_unlock(rq);
- raw_spin_unlock_irqrestore(&p->pi_lock, flags);
+ task_rq_unlock(rq, p, &flags);
return 0;
}
@@ -5300,27 +5304,17 @@ void idle_task_exit(void)
}
/*
- * While a dead CPU has no uninterruptible tasks queued at this point,
- * it might still have a nonzero ->nr_uninterruptible counter, because
- * for performance reasons the counter is not stricly tracking tasks to
- * their home CPUs. So we just add the counter to another CPU's counter,
- * to keep the global sum constant after CPU-down:
- */
-static void migrate_nr_uninterruptible(struct rq *rq_src)
-{
- struct rq *rq_dest = cpu_rq(cpumask_any(cpu_active_mask));
-
- rq_dest->nr_uninterruptible += rq_src->nr_uninterruptible;
- rq_src->nr_uninterruptible = 0;
-}
-
-/*
- * remove the tasks which were accounted by rq from calc_load_tasks.
+ * Since this CPU is going 'away' for a while, fold any nr_active delta
+ * we might have. Assumes we're called after migrate_tasks() so that the
+ * nr_active count is stable.
+ *
+ * Also see the comment "Global load-average calculations".
*/
-static void calc_global_load_remove(struct rq *rq)
+static void calc_load_migrate(struct rq *rq)
{
- atomic_long_sub(rq->calc_load_active, &calc_load_tasks);
- rq->calc_load_active = 0;
+ long delta = calc_load_fold_active(rq);
+ if (delta)
+ atomic_long_add(delta, &calc_load_tasks);
}
/*
@@ -5348,9 +5342,6 @@ static void migrate_tasks(unsigned int dead_cpu)
*/
rq->stop = NULL;
- /* Ensure any throttled groups are reachable by pick_next_task */
- unthrottle_offline_cfs_rqs(rq);
-
for ( ; ; ) {
/*
* There's this thread running, bail when that's the only
@@ -5614,8 +5605,7 @@ migration_call(struct notifier_block *nfb, unsigned long action, void *hcpu)
BUG_ON(rq->nr_running != 1); /* the migration thread */
raw_spin_unlock_irqrestore(&rq->lock, flags);
- migrate_nr_uninterruptible(rq);
- calc_global_load_remove(rq);
+ calc_load_migrate(rq);
break;
#endif
}
@@ -6024,11 +6014,6 @@ static void destroy_sched_domains(struct sched_domain *sd, int cpu)
* SD_SHARE_PKG_RESOURCE set (Last Level Cache Domain) for this
* allows us to avoid some pointer chasing select_idle_sibling().
*
- * Iterate domains and sched_groups downward, assigning CPUs to be
- * select_idle_sibling() hw buddy. Cross-wiring hw makes bouncing
- * due to random perturbation self canceling, ie sw buddies pull
- * their counterpart to their CPU's hw counterpart.
- *
* Also keep a unique ID per domain (we use the first cpu number in
* the cpumask of the domain), this allows us to quickly tell if
* two cpus are in the same cache domain, see cpus_share_cache().
@@ -6042,40 +6027,8 @@ static void update_top_cache_domain(int cpu)
int id = cpu;
sd = highest_flag_domain(cpu, SD_SHARE_PKG_RESOURCES);
- if (sd) {
- struct sched_domain *tmp = sd;
- struct sched_group *sg, *prev;
- bool right;
-
- /*
- * Traverse to first CPU in group, and count hops
- * to cpu from there, switching direction on each
- * hop, never ever pointing the last CPU rightward.
- */
- do {
- id = cpumask_first(sched_domain_span(tmp));
- prev = sg = tmp->groups;
- right = 1;
-
- while (cpumask_first(sched_group_cpus(sg)) != id)
- sg = sg->next;
-
- while (!cpumask_test_cpu(cpu, sched_group_cpus(sg))) {
- prev = sg;
- sg = sg->next;
- right = !right;
- }
-
- /* A CPU went down, never point back to domain start. */
- if (right && cpumask_first(sched_group_cpus(sg->next)) == id)
- right = false;
-
- sg = right ? sg->next : prev;
- tmp->idle_buddy = cpumask_first(sched_group_cpus(sg));
- } while ((tmp = tmp->child));
-
+ if (sd)
id = cpumask_first(sched_domain_span(sd));
- }
rcu_assign_pointer(per_cpu(sd_llc, cpu), sd);
per_cpu(sd_llc_id, cpu) = id;
@@ -7248,6 +7201,7 @@ int in_sched_functions(unsigned long addr)
#ifdef CONFIG_CGROUP_SCHED
struct task_group root_task_group;
+LIST_HEAD(task_groups);
#endif
DECLARE_PER_CPU(cpumask_var_t, load_balance_tmpmask);
diff --git a/kernel/sched/cpupri.c b/kernel/sched/cpupri.c
index d72586fdf660..23aa789c53ee 100644
--- a/kernel/sched/cpupri.c
+++ b/kernel/sched/cpupri.c
@@ -65,8 +65,8 @@ static int convert_prio(int prio)
int cpupri_find(struct cpupri *cp, struct task_struct *p,
struct cpumask *lowest_mask)
{
- int idx = 0;
- int task_pri = convert_prio(p->prio);
+ int idx = 0;
+ int task_pri = convert_prio(p->prio);
if (task_pri >= MAX_RT_PRIO)
return 0;
@@ -137,9 +137,9 @@ int cpupri_find(struct cpupri *cp, struct task_struct *p,
*/
void cpupri_set(struct cpupri *cp, int cpu, int newpri)
{
- int *currpri = &cp->cpu_to_pri[cpu];
- int oldpri = *currpri;
- int do_mb = 0;
+ int *currpri = &cp->cpu_to_pri[cpu];
+ int oldpri = *currpri;
+ int do_mb = 0;
newpri = convert_prio(newpri);
diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
index 22321db64952..96e2b18b6283 100644
--- a/kernel/sched/fair.c
+++ b/kernel/sched/fair.c
@@ -2052,7 +2052,7 @@ static void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b)
hrtimer_cancel(&cfs_b->slack_timer);
}
-void unthrottle_offline_cfs_rqs(struct rq *rq)
+static void unthrottle_offline_cfs_rqs(struct rq *rq)
{
struct cfs_rq *cfs_rq;
@@ -2106,7 +2106,7 @@ static inline struct cfs_bandwidth *tg_cfs_bandwidth(struct task_group *tg)
return NULL;
}
static inline void destroy_cfs_bandwidth(struct cfs_bandwidth *cfs_b) {}
-void unthrottle_offline_cfs_rqs(struct rq *rq) {}
+static inline void unthrottle_offline_cfs_rqs(struct rq *rq) {}
#endif /* CONFIG_CFS_BANDWIDTH */
@@ -2637,6 +2637,8 @@ static int select_idle_sibling(struct task_struct *p, int target)
int cpu = smp_processor_id();
int prev_cpu = task_cpu(p);
struct sched_domain *sd;
+ struct sched_group *sg;
+ int i;
/*
* If the task is going to be woken-up on this cpu and if it is
@@ -2653,17 +2655,29 @@ static int select_idle_sibling(struct task_struct *p, int target)
return prev_cpu;
/*
- * Otherwise, check assigned siblings to find an elegible idle cpu.
+ * Otherwise, iterate the domains and find an elegible idle cpu.
*/
sd = rcu_dereference(per_cpu(sd_llc, target));
-
for_each_lower_domain(sd) {
- if (!cpumask_test_cpu(sd->idle_buddy, tsk_cpus_allowed(p)))
- continue;
- if (idle_cpu(sd->idle_buddy))
- return sd->idle_buddy;
- }
+ sg = sd->groups;
+ do {
+ if (!cpumask_intersects(sched_group_cpus(sg),
+ tsk_cpus_allowed(p)))
+ goto next;
+ for_each_cpu(i, sched_group_cpus(sg)) {
+ if (!idle_cpu(i))
+ goto next;
+ }
+
+ target = cpumask_first_and(sched_group_cpus(sg),
+ tsk_cpus_allowed(p));
+ goto done;
+next:
+ sg = sg->next;
+ } while (sg != sd->groups);
+ }
+done:
return target;
}
@@ -3069,6 +3083,9 @@ struct lb_env {
int new_dst_cpu;
enum cpu_idle_type idle;
long imbalance;
+ /* The set of CPUs under consideration for load-balancing */
+ struct cpumask *cpus;
+
unsigned int flags;
unsigned int loop;
@@ -3384,6 +3401,14 @@ static int tg_load_down(struct task_group *tg, void *data)
static void update_h_load(long cpu)
{
+ struct rq *rq = cpu_rq(cpu);
+ unsigned long now = jiffies;
+
+ if (rq->h_load_throttle == now)
+ return;
+
+ rq->h_load_throttle = now;
+
rcu_read_lock();
walk_tg_tree(tg_load_down, tg_nop, (void *)cpu);
rcu_read_unlock();
@@ -3647,14 +3672,12 @@ fix_small_capacity(struct sched_domain *sd, struct sched_group *group)
* @group: sched_group whose statistics are to be updated.
* @load_idx: Load index of sched_domain of this_cpu for load calc.
* @local_group: Does group contain this_cpu.
- * @cpus: Set of cpus considered for load balancing.
* @balance: Should we balance.
* @sgs: variable to hold the statistics for this group.
*/
static inline void update_sg_lb_stats(struct lb_env *env,
struct sched_group *group, int load_idx,
- int local_group, const struct cpumask *cpus,
- int *balance, struct sg_lb_stats *sgs)
+ int local_group, int *balance, struct sg_lb_stats *sgs)
{
unsigned long nr_running, max_nr_running, min_nr_running;
unsigned long load, max_cpu_load, min_cpu_load;
@@ -3671,7 +3694,7 @@ static inline void update_sg_lb_stats(struct lb_env *env,
max_nr_running = 0;
min_nr_running = ~0UL;
- for_each_cpu_and(i, sched_group_cpus(group), cpus) {
+ for_each_cpu_and(i, sched_group_cpus(group), env->cpus) {
struct rq *rq = cpu_rq(i);
nr_running = rq->nr_running;
@@ -3795,13 +3818,11 @@ static bool update_sd_pick_busiest(struct lb_env *env,
/**
* update_sd_lb_stats - Update sched_domain's statistics for load balancing.
* @env: The load balancing environment.
- * @cpus: Set of cpus considered for load balancing.
* @balance: Should we balance.
* @sds: variable to hold the statistics for this sched_domain.
*/
static inline void update_sd_lb_stats(struct lb_env *env,
- const struct cpumask *cpus,
- int *balance, struct sd_lb_stats *sds)
+ int *balance, struct sd_lb_stats *sds)
{
struct sched_domain *child = env->sd->child;
struct sched_group *sg = env->sd->groups;
@@ -3818,8 +3839,7 @@ static inline void update_sd_lb_stats(struct lb_env *env,
local_group = cpumask_test_cpu(env->dst_cpu, sched_group_cpus(sg));
memset(&sgs, 0, sizeof(sgs));
- update_sg_lb_stats(env, sg, load_idx, local_group,
- cpus, balance, &sgs);
+ update_sg_lb_stats(env, sg, load_idx, local_group, balance, &sgs);
if (local_group && !(*balance))
return;
@@ -4055,7 +4075,6 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
* to restore balance.
*
* @env: The load balancing environment.
- * @cpus: The set of CPUs under consideration for load-balancing.
* @balance: Pointer to a variable indicating if this_cpu
* is the appropriate cpu to perform load balancing at this_level.
*
@@ -4065,7 +4084,7 @@ static inline void calculate_imbalance(struct lb_env *env, struct sd_lb_stats *s
* put to idle by rebalancing its tasks onto our group.
*/
static struct sched_group *
-find_busiest_group(struct lb_env *env, const struct cpumask *cpus, int *balance)
+find_busiest_group(struct lb_env *env, int *balance)
{
struct sd_lb_stats sds;
@@ -4075,7 +4094,7 @@ find_busiest_group(struct lb_env *env, const struct cpumask *cpus, int *balance)
* Compute the various statistics relavent for load balancing at
* this level.
*/
- update_sd_lb_stats(env, cpus, balance, &sds);
+ update_sd_lb_stats(env, balance, &sds);
/*
* this_cpu is not the appropriate cpu to perform load balancing at
@@ -4155,8 +4174,7 @@ ret:
* find_busiest_queue - find the busiest runqueue among the cpus in group.
*/
static struct rq *find_busiest_queue(struct lb_env *env,
- struct sched_group *group,
- const struct cpumask *cpus)
+ struct sched_group *group)
{
struct rq *busiest = NULL, *rq;
unsigned long max_load = 0;
@@ -4171,7 +4189,7 @@ static struct rq *find_busiest_queue(struct lb_env *env,
if (!capacity)
capacity = fix_small_capacity(env->sd, group);
- if (!cpumask_test_cpu(i, cpus))
+ if (!cpumask_test_cpu(i, env->cpus))
continue;
rq = cpu_rq(i);
@@ -4252,6 +4270,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
.dst_grpmask = sched_group_cpus(sd->groups),
.idle = idle,
.loop_break = sched_nr_migrate_break,
+ .cpus = cpus,
};
cpumask_copy(cpus, cpu_active_mask);
@@ -4260,7 +4279,7 @@ static int load_balance(int this_cpu, struct rq *this_rq,
schedstat_inc(sd, lb_count[idle]);
redo:
- group = find_busiest_group(&env, cpus, balance);
+ group = find_busiest_group(&env, balance);
if (*balance == 0)
goto out_balanced;
@@ -4270,7 +4289,7 @@ redo:
goto out_balanced;
}
- busiest = find_busiest_queue(&env, group, cpus);
+ busiest = find_busiest_queue(&env, group);
if (!busiest) {
schedstat_inc(sd, lb_nobusyq[idle]);
goto out_balanced;
@@ -4294,11 +4313,10 @@ redo:
env.src_rq = busiest;
env.loop_max = min(sysctl_sched_nr_migrate, busiest->nr_running);
+ update_h_load(env.src_cpu);
more_balance:
local_irq_save(flags);
double_rq_lock(this_rq, busiest);
- if (!env.loop)
- update_h_load(env.src_cpu);
/*
* cur_ld_moved - load moved in current iteration
@@ -4950,6 +4968,9 @@ static void rq_online_fair(struct rq *rq)
static void rq_offline_fair(struct rq *rq)
{
update_sysctl();
+
+ /* Ensure any throttled groups are reachable by pick_next_task */
+ unthrottle_offline_cfs_rqs(rq);
}
#endif /* CONFIG_SMP */
diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c
index 573e1ca01102..e0b7ba9c040f 100644
--- a/kernel/sched/rt.c
+++ b/kernel/sched/rt.c
@@ -691,6 +691,7 @@ balanced:
* runtime - in which case borrowing doesn't make sense.
*/
rt_rq->rt_runtime = RUNTIME_INF;
+ rt_rq->rt_throttled = 0;
raw_spin_unlock(&rt_rq->rt_runtime_lock);
raw_spin_unlock(&rt_b->rt_runtime_lock);
}
@@ -788,6 +789,19 @@ static int do_sched_rt_period_timer(struct rt_bandwidth *rt_b, int overrun)
const struct cpumask *span;
span = sched_rt_period_mask();
+#ifdef CONFIG_RT_GROUP_SCHED
+ /*
+ * FIXME: isolated CPUs should really leave the root task group,
+ * whether they are isolcpus or were isolated via cpusets, lest
+ * the timer run on a CPU which does not service all runqueues,
+ * potentially leaving other CPUs indefinitely throttled. If
+ * isolation is really required, the user will turn the throttle
+ * off to kill the perturbations it causes anyway. Meanwhile,
+ * this maintains functionality for boot and/or troubleshooting.
+ */
+ if (rt_b == &root_task_group.rt_bandwidth)
+ span = cpu_online_mask;
+#endif
for_each_cpu(i, span) {
int enqueue = 0;
struct rt_rq *rt_rq = sched_rt_period_rt_rq(rt_b, i);
diff --git a/kernel/sched/sched.h b/kernel/sched/sched.h
index c35a1a7dd4d6..0848fa36c383 100644
--- a/kernel/sched/sched.h
+++ b/kernel/sched/sched.h
@@ -80,7 +80,7 @@ extern struct mutex sched_domains_mutex;
struct cfs_rq;
struct rt_rq;
-static LIST_HEAD(task_groups);
+extern struct list_head task_groups;
struct cfs_bandwidth {
#ifdef CONFIG_CFS_BANDWIDTH
@@ -374,7 +374,11 @@ struct rq {
#ifdef CONFIG_FAIR_GROUP_SCHED
/* list of leaf cfs_rq on this cpu: */
struct list_head leaf_cfs_rq_list;
-#endif
+#ifdef CONFIG_SMP
+ unsigned long h_load_throttle;
+#endif /* CONFIG_SMP */
+#endif /* CONFIG_FAIR_GROUP_SCHED */
+
#ifdef CONFIG_RT_GROUP_SCHED
struct list_head leaf_rt_rq_list;
#endif
@@ -1140,7 +1144,6 @@ extern void print_rt_stats(struct seq_file *m, int cpu);
extern void init_cfs_rq(struct cfs_rq *cfs_rq);
extern void init_rt_rq(struct rt_rq *rt_rq, struct rq *rq);
-extern void unthrottle_offline_cfs_rqs(struct rq *rq);
extern void account_cfs_bandwidth_used(int enabled, int was_enabled);
diff --git a/kernel/sched/stop_task.c b/kernel/sched/stop_task.c
index 7b386e86fd23..da5eb5bed84a 100644
--- a/kernel/sched/stop_task.c
+++ b/kernel/sched/stop_task.c
@@ -27,8 +27,10 @@ static struct task_struct *pick_next_task_stop(struct rq *rq)
{
struct task_struct *stop = rq->stop;
- if (stop && stop->on_rq)
+ if (stop && stop->on_rq) {
+ stop->se.exec_start = rq->clock_task;
return stop;
+ }
return NULL;
}
@@ -52,6 +54,21 @@ static void yield_task_stop(struct rq *rq)
static void put_prev_task_stop(struct rq *rq, struct task_struct *prev)
{
+ struct task_struct *curr = rq->curr;
+ u64 delta_exec;
+
+ delta_exec = rq->clock_task - curr->se.exec_start;
+ if (unlikely((s64)delta_exec < 0))
+ delta_exec = 0;
+
+ schedstat_set(curr->se.statistics.exec_max,
+ max(curr->se.statistics.exec_max, delta_exec));
+
+ curr->se.sum_exec_runtime += delta_exec;
+ account_group_exec_runtime(curr, delta_exec);
+
+ curr->se.exec_start = rq->clock_task;
+ cpuacct_charge(curr, delta_exec);
}
static void task_tick_stop(struct rq *rq, struct task_struct *curr, int queued)
@@ -60,6 +77,9 @@ static void task_tick_stop(struct rq *rq, struct task_struct *curr, int queued)
static void set_curr_task_stop(struct rq *rq)
{
+ struct task_struct *stop = rq->stop;
+
+ stop->se.exec_start = rq->clock_task;
}
static void switched_to_stop(struct rq *rq, struct task_struct *p)
diff --git a/kernel/task_work.c b/kernel/task_work.c
index 91d4e1742a0c..d320d44903bd 100644
--- a/kernel/task_work.c
+++ b/kernel/task_work.c
@@ -75,6 +75,7 @@ void task_work_run(void)
p = q->next;
q->func(q);
q = p;
+ cond_resched();
}
}
}
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index a470154e0408..46da0537c10b 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -37,7 +37,7 @@
* requested HZ value. It is also not recommended
* for "tick-less" systems.
*/
-#define NSEC_PER_JIFFY ((u32)((((u64)NSEC_PER_SEC)<<8)/ACTHZ))
+#define NSEC_PER_JIFFY ((u32)((((u64)NSEC_PER_SEC)<<8)/SHIFTED_HZ))
/* Since jiffies uses a simple NSEC_PER_JIFFY multiplier
* conversion, the .shift value could be zero. However
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index b7fbadc5c973..24174b4d669b 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -28,7 +28,7 @@ DEFINE_SPINLOCK(ntp_lock);
/* USER_HZ period (usecs): */
unsigned long tick_usec = TICK_USEC;
-/* ACTHZ period (nsecs): */
+/* SHIFTED_HZ period (nsecs): */
unsigned long tick_nsec;
static u64 tick_length;
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 024540f97f74..3a9e5d5c1091 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -573,6 +573,7 @@ static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
tick_do_update_jiffies64(now);
update_cpu_load_nohz();
+ calc_load_exit_idle();
touch_softlockup_watchdog();
/*
* Cancel the scheduled timer and restore the tick
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index f045cc50832d..d3b91e75cecd 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -65,14 +65,14 @@ struct timekeeper {
* used instead.
*/
struct timespec wall_to_monotonic;
- /* time spent in suspend */
- struct timespec total_sleep_time;
- /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
- struct timespec raw_time;
/* Offset clock monotonic -> clock realtime */
ktime_t offs_real;
+ /* time spent in suspend */
+ struct timespec total_sleep_time;
/* Offset clock monotonic -> clock boottime */
ktime_t offs_boot;
+ /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
+ struct timespec raw_time;
/* Seqlock for all timekeeper values */
seqlock_t lock;
};
@@ -108,13 +108,39 @@ static struct timespec tk_xtime(struct timekeeper *tk)
static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts)
{
tk->xtime_sec = ts->tv_sec;
- tk->xtime_nsec = ts->tv_nsec << tk->shift;
+ tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift;
}
static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts)
{
tk->xtime_sec += ts->tv_sec;
- tk->xtime_nsec += ts->tv_nsec << tk->shift;
+ tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift;
+ tk_normalize_xtime(tk);
+}
+
+static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm)
+{
+ struct timespec tmp;
+
+ /*
+ * Verify consistency of: offset_real = -wall_to_monotonic
+ * before modifying anything
+ */
+ set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec,
+ -tk->wall_to_monotonic.tv_nsec);
+ WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64);
+ tk->wall_to_monotonic = wtm;
+ set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
+ tk->offs_real = timespec_to_ktime(tmp);
+}
+
+static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
+{
+ /* Verify consistency before modifying */
+ WARN_ON_ONCE(tk->offs_boot.tv64 != timespec_to_ktime(tk->total_sleep_time).tv64);
+
+ tk->total_sleep_time = t;
+ tk->offs_boot = timespec_to_ktime(t);
}
/**
@@ -217,14 +243,6 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
return nsec + arch_gettimeoffset();
}
-static void update_rt_offset(struct timekeeper *tk)
-{
- struct timespec tmp, *wtm = &tk->wall_to_monotonic;
-
- set_normalized_timespec(&tmp, -wtm->tv_sec, -wtm->tv_nsec);
- tk->offs_real = timespec_to_ktime(tmp);
-}
-
/* must hold write on timekeeper.lock */
static void timekeeping_update(struct timekeeper *tk, bool clearntp)
{
@@ -234,12 +252,10 @@ static void timekeeping_update(struct timekeeper *tk, bool clearntp)
tk->ntp_error = 0;
ntp_clear();
}
- update_rt_offset(tk);
xt = tk_xtime(tk);
update_vsyscall(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
}
-
/**
* timekeeping_forward_now - update clock to the current time
*
@@ -261,7 +277,7 @@ static void timekeeping_forward_now(struct timekeeper *tk)
tk->xtime_nsec += cycle_delta * tk->mult;
/* If arch requires, add in gettimeoffset() */
- tk->xtime_nsec += arch_gettimeoffset() << tk->shift;
+ tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift;
tk_normalize_xtime(tk);
@@ -277,38 +293,39 @@ static void timekeeping_forward_now(struct timekeeper *tk)
*/
void getnstimeofday(struct timespec *ts)
{
+ struct timekeeper *tk = &timekeeper;
unsigned long seq;
s64 nsecs = 0;
WARN_ON(timekeeping_suspended);
do {
- seq = read_seqbegin(&timekeeper.lock);
+ seq = read_seqbegin(&tk->lock);
- ts->tv_sec = timekeeper.xtime_sec;
- ts->tv_nsec = timekeeping_get_ns(&timekeeper);
+ ts->tv_sec = tk->xtime_sec;
+ nsecs = timekeeping_get_ns(tk);
- } while (read_seqretry(&timekeeper.lock, seq));
+ } while (read_seqretry(&tk->lock, seq));
+ ts->tv_nsec = 0;
timespec_add_ns(ts, nsecs);
}
EXPORT_SYMBOL(getnstimeofday);
ktime_t ktime_get(void)
{
+ struct timekeeper *tk = &timekeeper;
unsigned int seq;
s64 secs, nsecs;
WARN_ON(timekeeping_suspended);
do {
- seq = read_seqbegin(&timekeeper.lock);
- secs = timekeeper.xtime_sec +
- timekeeper.wall_to_monotonic.tv_sec;
- nsecs = timekeeping_get_ns(&timekeeper) +
- timekeeper.wall_to_monotonic.tv_nsec;
+ seq = read_seqbegin(&tk->lock);
+ secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
+ nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec;
- } while (read_seqretry(&timekeeper.lock, seq));
+ } while (read_seqretry(&tk->lock, seq));
/*
* Use ktime_set/ktime_add_ns to create a proper ktime on
* 32-bit architectures without CONFIG_KTIME_SCALAR.
@@ -327,21 +344,24 @@ EXPORT_SYMBOL_GPL(ktime_get);
*/
void ktime_get_ts(struct timespec *ts)
{
+ struct timekeeper *tk = &timekeeper;
struct timespec tomono;
+ s64 nsec;
unsigned int seq;
WARN_ON(timekeeping_suspended);
do {
- seq = read_seqbegin(&timekeeper.lock);
- ts->tv_sec = timekeeper.xtime_sec;
- ts->tv_nsec = timekeeping_get_ns(&timekeeper);
- tomono = timekeeper.wall_to_monotonic;
+ seq = read_seqbegin(&tk->lock);
+ ts->tv_sec = tk->xtime_sec;
+ nsec = timekeeping_get_ns(tk);
+ tomono = tk->wall_to_monotonic;
- } while (read_seqretry(&timekeeper.lock, seq));
+ } while (read_seqretry(&tk->lock, seq));
- set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
- ts->tv_nsec + tomono.tv_nsec);
+ ts->tv_sec += tomono.tv_sec;
+ ts->tv_nsec = 0;
+ timespec_add_ns(ts, nsec + tomono.tv_nsec);
}
EXPORT_SYMBOL_GPL(ktime_get_ts);
@@ -358,22 +378,23 @@ EXPORT_SYMBOL_GPL(ktime_get_ts);
*/
void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
{
+ struct timekeeper *tk = &timekeeper;
unsigned long seq;
s64 nsecs_raw, nsecs_real;
WARN_ON_ONCE(timekeeping_suspended);
do {
- seq = read_seqbegin(&timekeeper.lock);
+ seq = read_seqbegin(&tk->lock);
- *ts_raw = timekeeper.raw_time;
- ts_real->tv_sec = timekeeper.xtime_sec;
+ *ts_raw = tk->raw_time;
+ ts_real->tv_sec = tk->xtime_sec;
ts_real->tv_nsec = 0;
- nsecs_raw = timekeeping_get_ns_raw(&timekeeper);
- nsecs_real = timekeeping_get_ns(&timekeeper);
+ nsecs_raw = timekeeping_get_ns_raw(tk);
+ nsecs_real = timekeeping_get_ns(tk);
- } while (read_seqretry(&timekeeper.lock, seq));
+ } while (read_seqretry(&tk->lock, seq));
timespec_add_ns(ts_raw, nsecs_raw);
timespec_add_ns(ts_real, nsecs_real);
@@ -406,28 +427,28 @@ EXPORT_SYMBOL(do_gettimeofday);
*/
int do_settimeofday(const struct timespec *tv)
{
+ struct timekeeper *tk = &timekeeper;
struct timespec ts_delta, xt;
unsigned long flags;
- if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
+ if (!timespec_valid_strict(tv))
return -EINVAL;
- write_seqlock_irqsave(&timekeeper.lock, flags);
+ write_seqlock_irqsave(&tk->lock, flags);
- timekeeping_forward_now(&timekeeper);
+ timekeeping_forward_now(tk);
- xt = tk_xtime(&timekeeper);
+ xt = tk_xtime(tk);
ts_delta.tv_sec = tv->tv_sec - xt.tv_sec;
ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec;
- timekeeper.wall_to_monotonic =
- timespec_sub(timekeeper.wall_to_monotonic, ts_delta);
+ tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta));
- tk_set_xtime(&timekeeper, tv);
+ tk_set_xtime(tk, tv);
- timekeeping_update(&timekeeper, true);
+ timekeeping_update(tk, true);
- write_sequnlock_irqrestore(&timekeeper.lock, flags);
+ write_sequnlock_irqrestore(&tk->lock, flags);
/* signal hrtimers about time change */
clock_was_set();
@@ -436,7 +457,6 @@ int do_settimeofday(const struct timespec *tv)
}
EXPORT_SYMBOL(do_settimeofday);
-
/**
* timekeeping_inject_offset - Adds or subtracts from the current time.
* @tv: pointer to the timespec variable containing the offset
@@ -445,28 +465,37 @@ EXPORT_SYMBOL(do_settimeofday);
*/
int timekeeping_inject_offset(struct timespec *ts)
{
+ struct timekeeper *tk = &timekeeper;
unsigned long flags;
+ struct timespec tmp;
+ int ret = 0;
if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
return -EINVAL;
- write_seqlock_irqsave(&timekeeper.lock, flags);
+ write_seqlock_irqsave(&tk->lock, flags);
- timekeeping_forward_now(&timekeeper);
+ timekeeping_forward_now(tk);
+ /* Make sure the proposed value is valid */
+ tmp = timespec_add(tk_xtime(tk), *ts);
+ if (!timespec_valid_strict(&tmp)) {
+ ret = -EINVAL;
+ goto error;
+ }
- tk_xtime_add(&timekeeper, ts);
- timekeeper.wall_to_monotonic =
- timespec_sub(timekeeper.wall_to_monotonic, *ts);
+ tk_xtime_add(tk, ts);
+ tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts));
- timekeeping_update(&timekeeper, true);
+error: /* even if we error out, we forwarded the time, so call update */
+ timekeeping_update(tk, true);
- write_sequnlock_irqrestore(&timekeeper.lock, flags);
+ write_sequnlock_irqrestore(&tk->lock, flags);
/* signal hrtimers about time change */
clock_was_set();
- return 0;
+ return ret;
}
EXPORT_SYMBOL(timekeeping_inject_offset);
@@ -477,23 +506,24 @@ EXPORT_SYMBOL(timekeeping_inject_offset);
*/
static int change_clocksource(void *data)
{
+ struct timekeeper *tk = &timekeeper;
struct clocksource *new, *old;
unsigned long flags;
new = (struct clocksource *) data;
- write_seqlock_irqsave(&timekeeper.lock, flags);
+ write_seqlock_irqsave(&tk->lock, flags);
- timekeeping_forward_now(&timekeeper);
+ timekeeping_forward_now(tk);
if (!new->enable || new->enable(new) == 0) {
- old = timekeeper.clock;
- tk_setup_internals(&timekeeper, new);
+ old = tk->clock;
+ tk_setup_internals(tk, new);
if (old->disable)
old->disable(old);
}
- timekeeping_update(&timekeeper, true);
+ timekeeping_update(tk, true);
- write_sequnlock_irqrestore(&timekeeper.lock, flags);
+ write_sequnlock_irqrestore(&tk->lock, flags);
return 0;
}
@@ -507,7 +537,9 @@ static int change_clocksource(void *data)
*/
void timekeeping_notify(struct clocksource *clock)
{
- if (timekeeper.clock == clock)
+ struct timekeeper *tk = &timekeeper;
+
+ if (tk->clock == clock)
return;
stop_machine(change_clocksource, clock, NULL);
tick_clock_notify();
@@ -536,35 +568,36 @@ EXPORT_SYMBOL_GPL(ktime_get_real);
*/
void getrawmonotonic(struct timespec *ts)
{
+ struct timekeeper *tk = &timekeeper;
unsigned long seq;
s64 nsecs;
do {
- seq = read_seqbegin(&timekeeper.lock);
- nsecs = timekeeping_get_ns_raw(&timekeeper);
- *ts = timekeeper.raw_time;
+ seq = read_seqbegin(&tk->lock);
+ nsecs = timekeeping_get_ns_raw(tk);
+ *ts = tk->raw_time;
- } while (read_seqretry(&timekeeper.lock, seq));
+ } while (read_seqretry(&tk->lock, seq));
timespec_add_ns(ts, nsecs);
}
EXPORT_SYMBOL(getrawmonotonic);
-
/**
* timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
*/
int timekeeping_valid_for_hres(void)
{
+ struct timekeeper *tk = &timekeeper;
unsigned long seq;
int ret;
do {
- seq = read_seqbegin(&timekeeper.lock);
+ seq = read_seqbegin(&tk->lock);
- ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
+ ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
- } while (read_seqretry(&timekeeper.lock, seq));
+ } while (read_seqretry(&tk->lock, seq));
return ret;
}
@@ -574,15 +607,16 @@ int timekeeping_valid_for_hres(void)
*/
u64 timekeeping_max_deferment(void)
{
+ struct timekeeper *tk = &timekeeper;
unsigned long seq;
u64 ret;
do {
- seq = read_seqbegin(&timekeeper.lock);
+ seq = read_seqbegin(&tk->lock);
- ret = timekeeper.clock->max_idle_ns;
+ ret = tk->clock->max_idle_ns;
- } while (read_seqretry(&timekeeper.lock, seq));
+ } while (read_seqretry(&tk->lock, seq));
return ret;
}
@@ -622,46 +656,56 @@ void __attribute__((weak)) read_boot_clock(struct timespec *ts)
*/
void __init timekeeping_init(void)
{
+ struct timekeeper *tk = &timekeeper;
struct clocksource *clock;
unsigned long flags;
- struct timespec now, boot;
+ struct timespec now, boot, tmp;
read_persistent_clock(&now);
+ if (!timespec_valid_strict(&now)) {
+ pr_warn("WARNING: Persistent clock returned invalid value!\n"
+ " Check your CMOS/BIOS settings.\n");
+ now.tv_sec = 0;
+ now.tv_nsec = 0;
+ }
+
read_boot_clock(&boot);
+ if (!timespec_valid_strict(&boot)) {
+ pr_warn("WARNING: Boot clock returned invalid value!\n"
+ " Check your CMOS/BIOS settings.\n");
+ boot.tv_sec = 0;
+ boot.tv_nsec = 0;
+ }
- seqlock_init(&timekeeper.lock);
+ seqlock_init(&tk->lock);
ntp_init();
- write_seqlock_irqsave(&timekeeper.lock, flags);
+ write_seqlock_irqsave(&tk->lock, flags);
clock = clocksource_default_clock();
if (clock->enable)
clock->enable(clock);
- tk_setup_internals(&timekeeper, clock);
+ tk_setup_internals(tk, clock);
- tk_set_xtime(&timekeeper, &now);
- timekeeper.raw_time.tv_sec = 0;
- timekeeper.raw_time.tv_nsec = 0;
+ tk_set_xtime(tk, &now);
+ tk->raw_time.tv_sec = 0;
+ tk->raw_time.tv_nsec = 0;
if (boot.tv_sec == 0 && boot.tv_nsec == 0)
- boot = tk_xtime(&timekeeper);
-
- set_normalized_timespec(&timekeeper.wall_to_monotonic,
- -boot.tv_sec, -boot.tv_nsec);
- update_rt_offset(&timekeeper);
- timekeeper.total_sleep_time.tv_sec = 0;
- timekeeper.total_sleep_time.tv_nsec = 0;
- write_sequnlock_irqrestore(&timekeeper.lock, flags);
+ boot = tk_xtime(tk);
+
+ set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec);
+ tk_set_wall_to_mono(tk, tmp);
+
+ tmp.tv_sec = 0;
+ tmp.tv_nsec = 0;
+ tk_set_sleep_time(tk, tmp);
+
+ write_sequnlock_irqrestore(&tk->lock, flags);
}
/* time in seconds when suspend began */
static struct timespec timekeeping_suspend_time;
-static void update_sleep_time(struct timespec t)
-{
- timekeeper.total_sleep_time = t;
- timekeeper.offs_boot = timespec_to_ktime(t);
-}
-
/**
* __timekeeping_inject_sleeptime - Internal function to add sleep interval
* @delta: pointer to a timespec delta value
@@ -672,18 +716,16 @@ static void update_sleep_time(struct timespec t)
static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
struct timespec *delta)
{
- if (!timespec_valid(delta)) {
+ if (!timespec_valid_strict(delta)) {
printk(KERN_WARNING "__timekeeping_inject_sleeptime: Invalid "
"sleep delta value!\n");
return;
}
-
tk_xtime_add(tk, delta);
- tk->wall_to_monotonic = timespec_sub(tk->wall_to_monotonic, *delta);
- update_sleep_time(timespec_add(tk->total_sleep_time, *delta));
+ tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *delta));
+ tk_set_sleep_time(tk, timespec_add(tk->total_sleep_time, *delta));
}
-
/**
* timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
* @delta: pointer to a timespec delta value
@@ -696,6 +738,7 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
*/
void timekeeping_inject_sleeptime(struct timespec *delta)
{
+ struct timekeeper *tk = &timekeeper;
unsigned long flags;
struct timespec ts;
@@ -704,21 +747,20 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
return;
- write_seqlock_irqsave(&timekeeper.lock, flags);
+ write_seqlock_irqsave(&tk->lock, flags);
- timekeeping_forward_now(&timekeeper);
+ timekeeping_forward_now(tk);
- __timekeeping_inject_sleeptime(&timekeeper, delta);
+ __timekeeping_inject_sleeptime(tk, delta);
- timekeeping_update(&timekeeper, true);
+ timekeeping_update(tk, true);
- write_sequnlock_irqrestore(&timekeeper.lock, flags);
+ write_sequnlock_irqrestore(&tk->lock, flags);
/* signal hrtimers about time change */
clock_was_set();
}
-
/**
* timekeeping_resume - Resumes the generic timekeeping subsystem.
*
@@ -728,6 +770,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
*/
static void timekeeping_resume(void)
{
+ struct timekeeper *tk = &timekeeper;
unsigned long flags;
struct timespec ts;
@@ -735,18 +778,18 @@ static void timekeeping_resume(void)
clocksource_resume();
- write_seqlock_irqsave(&timekeeper.lock, flags);
+ write_seqlock_irqsave(&tk->lock, flags);
if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
ts = timespec_sub(ts, timekeeping_suspend_time);
- __timekeeping_inject_sleeptime(&timekeeper, &ts);
+ __timekeeping_inject_sleeptime(tk, &ts);
}
/* re-base the last cycle value */
- timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
- timekeeper.ntp_error = 0;
+ tk->clock->cycle_last = tk->clock->read(tk->clock);
+ tk->ntp_error = 0;
timekeeping_suspended = 0;
- timekeeping_update(&timekeeper, false);
- write_sequnlock_irqrestore(&timekeeper.lock, flags);
+ timekeeping_update(tk, false);
+ write_sequnlock_irqrestore(&tk->lock, flags);
touch_softlockup_watchdog();
@@ -758,14 +801,15 @@ static void timekeeping_resume(void)
static int timekeeping_suspend(void)
{
+ struct timekeeper *tk = &timekeeper;
unsigned long flags;
struct timespec delta, delta_delta;
static struct timespec old_delta;
read_persistent_clock(&timekeeping_suspend_time);
- write_seqlock_irqsave(&timekeeper.lock, flags);
- timekeeping_forward_now(&timekeeper);
+ write_seqlock_irqsave(&tk->lock, flags);
+ timekeeping_forward_now(tk);
timekeeping_suspended = 1;
/*
@@ -774,7 +818,7 @@ static int timekeeping_suspend(void)
* try to compensate so the difference in system time
* and persistent_clock time stays close to constant.
*/
- delta = timespec_sub(tk_xtime(&timekeeper), timekeeping_suspend_time);
+ delta = timespec_sub(tk_xtime(tk), timekeeping_suspend_time);
delta_delta = timespec_sub(delta, old_delta);
if (abs(delta_delta.tv_sec) >= 2) {
/*
@@ -787,7 +831,7 @@ static int timekeeping_suspend(void)
timekeeping_suspend_time =
timespec_add(timekeeping_suspend_time, delta_delta);
}
- write_sequnlock_irqrestore(&timekeeper.lock, flags);
+ write_sequnlock_irqrestore(&tk->lock, flags);
clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
clocksource_suspend();
@@ -898,27 +942,29 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
* the error. This causes the likely below to be unlikely.
*
* The proper fix is to avoid rounding up by using
- * the high precision timekeeper.xtime_nsec instead of
+ * the high precision tk->xtime_nsec instead of
* xtime.tv_nsec everywhere. Fixing this will take some
* time.
*/
if (likely(error <= interval))
adj = 1;
else
- adj = timekeeping_bigadjust(tk, error, &interval,
- &offset);
- } else if (error < -interval) {
- /* See comment above, this is just switched for the negative */
- error >>= 2;
- if (likely(error >= -interval)) {
- adj = -1;
- interval = -interval;
- offset = -offset;
- } else
- adj = timekeeping_bigadjust(tk, error, &interval,
- &offset);
- } else
- return;
+ adj = timekeeping_bigadjust(tk, error, &interval, &offset);
+ } else {
+ if (error < -interval) {
+ /* See comment above, this is just switched for the negative */
+ error >>= 2;
+ if (likely(error >= -interval)) {
+ adj = -1;
+ interval = -interval;
+ offset = -offset;
+ } else {
+ adj = timekeeping_bigadjust(tk, error, &interval, &offset);
+ }
+ } else {
+ goto out_adjust;
+ }
+ }
if (unlikely(tk->clock->maxadj &&
(tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) {
@@ -981,6 +1027,7 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
tk->xtime_nsec -= offset;
tk->ntp_error -= (interval - offset) << tk->ntp_error_shift;
+out_adjust:
/*
* It may be possible that when we entered this function, xtime_nsec
* was very small. Further, if we're slightly speeding the clocksource
@@ -1003,7 +1050,6 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
}
-
/**
* accumulate_nsecs_to_secs - Accumulates nsecs into secs
*
@@ -1024,15 +1070,21 @@ static inline void accumulate_nsecs_to_secs(struct timekeeper *tk)
/* Figure out if its a leap sec and apply if needed */
leap = second_overflow(tk->xtime_sec);
- tk->xtime_sec += leap;
- tk->wall_to_monotonic.tv_sec -= leap;
- if (leap)
- clock_was_set_delayed();
+ if (unlikely(leap)) {
+ struct timespec ts;
+
+ tk->xtime_sec += leap;
+
+ ts.tv_sec = leap;
+ ts.tv_nsec = 0;
+ tk_set_wall_to_mono(tk,
+ timespec_sub(tk->wall_to_monotonic, ts));
+ clock_was_set_delayed();
+ }
}
}
-
/**
* logarithmic_accumulation - shifted accumulation of cycles
*
@@ -1076,7 +1128,6 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
return offset;
}
-
/**
* update_wall_time - Uses the current clocksource to increment the wall time
*
@@ -1084,25 +1135,30 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
static void update_wall_time(void)
{
struct clocksource *clock;
+ struct timekeeper *tk = &timekeeper;
cycle_t offset;
int shift = 0, maxshift;
unsigned long flags;
s64 remainder;
- write_seqlock_irqsave(&timekeeper.lock, flags);
+ write_seqlock_irqsave(&tk->lock, flags);
/* Make sure we're fully resumed: */
if (unlikely(timekeeping_suspended))
goto out;
- clock = timekeeper.clock;
+ clock = tk->clock;
#ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
- offset = timekeeper.cycle_interval;
+ offset = tk->cycle_interval;
#else
offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
#endif
+ /* Check if there's really nothing to do */
+ if (offset < tk->cycle_interval)
+ goto out;
+
/*
* With NO_HZ we may have to accumulate many cycle_intervals
* (think "ticks") worth of time at once. To do this efficiently,
@@ -1111,19 +1167,19 @@ static void update_wall_time(void)
* chunk in one go, and then try to consume the next smaller
* doubled multiple.
*/
- shift = ilog2(offset) - ilog2(timekeeper.cycle_interval);
+ shift = ilog2(offset) - ilog2(tk->cycle_interval);
shift = max(0, shift);
/* Bound shift to one less than what overflows tick_length */
maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
shift = min(shift, maxshift);
- while (offset >= timekeeper.cycle_interval) {
- offset = logarithmic_accumulation(&timekeeper, offset, shift);
- if(offset < timekeeper.cycle_interval<<shift)
+ while (offset >= tk->cycle_interval) {
+ offset = logarithmic_accumulation(tk, offset, shift);
+ if (offset < tk->cycle_interval<<shift)
shift--;
}
/* correct the clock when NTP error is too big */
- timekeeping_adjust(&timekeeper, offset);
+ timekeeping_adjust(tk, offset);
/*
@@ -1135,21 +1191,21 @@ static void update_wall_time(void)
* the vsyscall implementations are converted to use xtime_nsec
* (shifted nanoseconds), this can be killed.
*/
- remainder = timekeeper.xtime_nsec & ((1 << timekeeper.shift) - 1);
- timekeeper.xtime_nsec -= remainder;
- timekeeper.xtime_nsec += 1 << timekeeper.shift;
- timekeeper.ntp_error += remainder << timekeeper.ntp_error_shift;
+ remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1);
+ tk->xtime_nsec -= remainder;
+ tk->xtime_nsec += 1ULL << tk->shift;
+ tk->ntp_error += remainder << tk->ntp_error_shift;
/*
* Finally, make sure that after the rounding
* xtime_nsec isn't larger than NSEC_PER_SEC
*/
- accumulate_nsecs_to_secs(&timekeeper);
+ accumulate_nsecs_to_secs(tk);
- timekeeping_update(&timekeeper, false);
+ timekeeping_update(tk, false);
out:
- write_sequnlock_irqrestore(&timekeeper.lock, flags);
+ write_sequnlock_irqrestore(&tk->lock, flags);
}
@@ -1166,18 +1222,18 @@ out:
*/
void getboottime(struct timespec *ts)
{
+ struct timekeeper *tk = &timekeeper;
struct timespec boottime = {
- .tv_sec = timekeeper.wall_to_monotonic.tv_sec +
- timekeeper.total_sleep_time.tv_sec,
- .tv_nsec = timekeeper.wall_to_monotonic.tv_nsec +
- timekeeper.total_sleep_time.tv_nsec
+ .tv_sec = tk->wall_to_monotonic.tv_sec +
+ tk->total_sleep_time.tv_sec,
+ .tv_nsec = tk->wall_to_monotonic.tv_nsec +
+ tk->total_sleep_time.tv_nsec
};
set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
}
EXPORT_SYMBOL_GPL(getboottime);
-
/**
* get_monotonic_boottime - Returns monotonic time since boot
* @ts: pointer to the timespec to be set
@@ -1189,22 +1245,25 @@ EXPORT_SYMBOL_GPL(getboottime);
*/
void get_monotonic_boottime(struct timespec *ts)
{
+ struct timekeeper *tk = &timekeeper;
struct timespec tomono, sleep;
+ s64 nsec;
unsigned int seq;
WARN_ON(timekeeping_suspended);
do {
- seq = read_seqbegin(&timekeeper.lock);
- ts->tv_sec = timekeeper.xtime_sec;
- ts->tv_nsec = timekeeping_get_ns(&timekeeper);
- tomono = timekeeper.wall_to_monotonic;
- sleep = timekeeper.total_sleep_time;
+ seq = read_seqbegin(&tk->lock);
+ ts->tv_sec = tk->xtime_sec;
+ nsec = timekeeping_get_ns(tk);
+ tomono = tk->wall_to_monotonic;
+ sleep = tk->total_sleep_time;
- } while (read_seqretry(&timekeeper.lock, seq));
+ } while (read_seqretry(&tk->lock, seq));
- set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec,
- ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec);
+ ts->tv_sec += tomono.tv_sec + sleep.tv_sec;
+ ts->tv_nsec = 0;
+ timespec_add_ns(ts, nsec + tomono.tv_nsec + sleep.tv_nsec);
}
EXPORT_SYMBOL_GPL(get_monotonic_boottime);
@@ -1231,31 +1290,38 @@ EXPORT_SYMBOL_GPL(ktime_get_boottime);
*/
void monotonic_to_bootbased(struct timespec *ts)
{
- *ts = timespec_add(*ts, timekeeper.total_sleep_time);
+ struct timekeeper *tk = &timekeeper;
+
+ *ts = timespec_add(*ts, tk->total_sleep_time);
}
EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
unsigned long get_seconds(void)
{
- return timekeeper.xtime_sec;
+ struct timekeeper *tk = &timekeeper;
+
+ return tk->xtime_sec;
}
EXPORT_SYMBOL(get_seconds);
struct timespec __current_kernel_time(void)
{
- return tk_xtime(&timekeeper);
+ struct timekeeper *tk = &timekeeper;
+
+ return tk_xtime(tk);
}
struct timespec current_kernel_time(void)
{
+ struct timekeeper *tk = &timekeeper;
struct timespec now;
unsigned long seq;
do {
- seq = read_seqbegin(&timekeeper.lock);
+ seq = read_seqbegin(&tk->lock);
- now = tk_xtime(&timekeeper);
- } while (read_seqretry(&timekeeper.lock, seq));
+ now = tk_xtime(tk);
+ } while (read_seqretry(&tk->lock, seq));
return now;
}
@@ -1263,15 +1329,16 @@ EXPORT_SYMBOL(current_kernel_time);
struct timespec get_monotonic_coarse(void)
{
+ struct timekeeper *tk = &timekeeper;
struct timespec now, mono;
unsigned long seq;
do {
- seq = read_seqbegin(&timekeeper.lock);
+ seq = read_seqbegin(&tk->lock);
- now = tk_xtime(&timekeeper);
- mono = timekeeper.wall_to_monotonic;
- } while (read_seqretry(&timekeeper.lock, seq));
+ now = tk_xtime(tk);
+ mono = tk->wall_to_monotonic;
+ } while (read_seqretry(&tk->lock, seq));
set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
now.tv_nsec + mono.tv_nsec);
@@ -1300,14 +1367,15 @@ void do_timer(unsigned long ticks)
void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
struct timespec *wtom, struct timespec *sleep)
{
+ struct timekeeper *tk = &timekeeper;
unsigned long seq;
do {
- seq = read_seqbegin(&timekeeper.lock);
- *xtim = tk_xtime(&timekeeper);
- *wtom = timekeeper.wall_to_monotonic;
- *sleep = timekeeper.total_sleep_time;
- } while (read_seqretry(&timekeeper.lock, seq));
+ seq = read_seqbegin(&tk->lock);
+ *xtim = tk_xtime(tk);
+ *wtom = tk->wall_to_monotonic;
+ *sleep = tk->total_sleep_time;
+ } while (read_seqretry(&tk->lock, seq));
}
#ifdef CONFIG_HIGH_RES_TIMERS
@@ -1321,19 +1389,20 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
*/
ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
{
+ struct timekeeper *tk = &timekeeper;
ktime_t now;
unsigned int seq;
u64 secs, nsecs;
do {
- seq = read_seqbegin(&timekeeper.lock);
+ seq = read_seqbegin(&tk->lock);
- secs = timekeeper.xtime_sec;
- nsecs = timekeeping_get_ns(&timekeeper);
+ secs = tk->xtime_sec;
+ nsecs = timekeeping_get_ns(tk);
- *offs_real = timekeeper.offs_real;
- *offs_boot = timekeeper.offs_boot;
- } while (read_seqretry(&timekeeper.lock, seq));
+ *offs_real = tk->offs_real;
+ *offs_boot = tk->offs_boot;
+ } while (read_seqretry(&tk->lock, seq));
now = ktime_add_ns(ktime_set(secs, 0), nsecs);
now = ktime_sub(now, *offs_real);
@@ -1346,19 +1415,19 @@ ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
*/
ktime_t ktime_get_monotonic_offset(void)
{
+ struct timekeeper *tk = &timekeeper;
unsigned long seq;
struct timespec wtom;
do {
- seq = read_seqbegin(&timekeeper.lock);
- wtom = timekeeper.wall_to_monotonic;
- } while (read_seqretry(&timekeeper.lock, seq));
+ seq = read_seqbegin(&tk->lock);
+ wtom = tk->wall_to_monotonic;
+ } while (read_seqretry(&tk->lock, seq));
return timespec_to_ktime(wtom);
}
EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset);
-
/**
* xtime_update() - advances the timekeeping infrastructure
* @ticks: number of ticks, that have elapsed since the last call.
diff --git a/kernel/timer.c b/kernel/timer.c
index a61c09374eba..8c5e7b908c68 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -1407,13 +1407,6 @@ SYSCALL_DEFINE1(alarm, unsigned int, seconds)
#endif
-#ifndef __alpha__
-
-/*
- * The Alpha uses getxpid, getxuid, and getxgid instead. Maybe this
- * should be moved into arch/i386 instead?
- */
-
/**
* sys_getpid - return the thread group id of the current process
*
@@ -1469,8 +1462,6 @@ SYSCALL_DEFINE0(getegid)
return from_kgid_munged(current_user_ns(), current_egid());
}
-#endif
-
static void process_timeout(unsigned long __data)
{
wake_up_process((struct task_struct *)__data);
diff --git a/kernel/trace/trace_event_perf.c b/kernel/trace/trace_event_perf.c
index fee3752ae8f6..8a6d2ee2086c 100644
--- a/kernel/trace/trace_event_perf.c
+++ b/kernel/trace/trace_event_perf.c
@@ -281,7 +281,7 @@ perf_ftrace_function_call(unsigned long ip, unsigned long parent_ip)
head = this_cpu_ptr(event_function.perf_events);
perf_trace_buf_submit(entry, ENTRY_SIZE, rctx, 0,
- 1, &regs, head);
+ 1, &regs, head, NULL);
#undef ENTRY_SIZE
}
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index b31d3d5699fe..1a2117043bb1 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -1002,7 +1002,8 @@ static __kprobes void kprobe_perf_func(struct kprobe *kp,
store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
head = this_cpu_ptr(call->perf_events);
- perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head);
+ perf_trace_buf_submit(entry, size, rctx,
+ entry->ip, 1, regs, head, NULL);
}
/* Kretprobe profile handler */
@@ -1033,7 +1034,8 @@ static __kprobes void kretprobe_perf_func(struct kretprobe_instance *ri,
store_trace_args(sizeof(*entry), tp, regs, (u8 *)&entry[1], dsize);
head = this_cpu_ptr(call->perf_events);
- perf_trace_buf_submit(entry, size, rctx, entry->ret_ip, 1, regs, head);
+ perf_trace_buf_submit(entry, size, rctx,
+ entry->ret_ip, 1, regs, head, NULL);
}
#endif /* CONFIG_PERF_EVENTS */
diff --git a/kernel/trace/trace_syscalls.c b/kernel/trace/trace_syscalls.c
index 96fc73369099..6b245f64c8dd 100644
--- a/kernel/trace/trace_syscalls.c
+++ b/kernel/trace/trace_syscalls.c
@@ -506,6 +506,8 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
int size;
syscall_nr = syscall_get_nr(current, regs);
+ if (syscall_nr < 0)
+ return;
if (!test_bit(syscall_nr, enabled_perf_enter_syscalls))
return;
@@ -532,7 +534,7 @@ static void perf_syscall_enter(void *ignore, struct pt_regs *regs, long id)
(unsigned long *)&rec->args);
head = this_cpu_ptr(sys_data->enter_event->perf_events);
- perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head);
+ perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
}
int perf_sysenter_enable(struct ftrace_event_call *call)
@@ -580,6 +582,8 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
int size;
syscall_nr = syscall_get_nr(current, regs);
+ if (syscall_nr < 0)
+ return;
if (!test_bit(syscall_nr, enabled_perf_exit_syscalls))
return;
@@ -608,7 +612,7 @@ static void perf_syscall_exit(void *ignore, struct pt_regs *regs, long ret)
rec->ret = syscall_get_return_value(current, regs);
head = this_cpu_ptr(sys_data->exit_event->perf_events);
- perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head);
+ perf_trace_buf_submit(rec, size, rctx, 0, 1, regs, head, NULL);
}
int perf_sysexit_enable(struct ftrace_event_call *call)
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 2b36ac68549e..03003cd7dd96 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -670,7 +670,7 @@ static void uprobe_perf_func(struct trace_uprobe *tu, struct pt_regs *regs)
call_fetch(&tu->args[i].fetch, regs, data + tu->args[i].offset);
head = this_cpu_ptr(call->perf_events);
- perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head);
+ perf_trace_buf_submit(entry, size, rctx, entry->ip, 1, regs, head, NULL);
out:
preempt_enable();
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index 69add8a9da68..4b1dfba70f7c 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -575,7 +575,7 @@ out:
/*
* Create/destroy watchdog threads as CPUs come and go:
*/
-static int
+static int __cpuinit
cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
{
int hotcpu = (unsigned long)hcpu;
@@ -610,27 +610,10 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
return NOTIFY_OK;
}
-static struct notifier_block cpu_nfb = {
+static struct notifier_block __cpuinitdata cpu_nfb = {
.notifier_call = cpu_callback
};
-#ifdef CONFIG_SUSPEND
-/*
- * On exit from suspend we force an offline->online transition on the boot CPU
- * so that the PMU state that was lost while in suspended state gets set up
- * properly for the boot CPU. This information is required for restarting the
- * NMI watchdog.
- */
-void lockup_detector_bootcpu_resume(void)
-{
- void *cpu = (void *)(long)smp_processor_id();
-
- cpu_callback(&cpu_nfb, CPU_DEAD_FROZEN, cpu);
- cpu_callback(&cpu_nfb, CPU_UP_PREPARE_FROZEN, cpu);
- cpu_callback(&cpu_nfb, CPU_ONLINE_FROZEN, cpu);
-}
-#endif
-
void __init lockup_detector_init(void)
{
void *cpu = (void *)(long)smp_processor_id();
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index 692d97628a10..3c5a79e2134c 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -66,6 +66,7 @@ enum {
/* pool flags */
POOL_MANAGE_WORKERS = 1 << 0, /* need to manage workers */
+ POOL_MANAGING_WORKERS = 1 << 1, /* managing workers */
/* worker flags */
WORKER_STARTED = 1 << 0, /* started */
@@ -652,7 +653,7 @@ static bool need_to_manage_workers(struct worker_pool *pool)
/* Do we have too many workers and should some go away? */
static bool too_many_workers(struct worker_pool *pool)
{
- bool managing = mutex_is_locked(&pool->manager_mutex);
+ bool managing = pool->flags & POOL_MANAGING_WORKERS;
int nr_idle = pool->nr_idle + managing; /* manager is considered idle */
int nr_busy = pool->nr_workers - nr_idle;
@@ -1326,6 +1327,15 @@ static void idle_worker_rebind(struct worker *worker)
/* we did our part, wait for rebind_workers() to finish up */
wait_event(gcwq->rebind_hold, !(worker->flags & WORKER_REBIND));
+
+ /*
+ * rebind_workers() shouldn't finish until all workers passed the
+ * above WORKER_REBIND wait. Tell it when done.
+ */
+ spin_lock_irq(&worker->pool->gcwq->lock);
+ if (!--worker->idle_rebind->cnt)
+ complete(&worker->idle_rebind->done);
+ spin_unlock_irq(&worker->pool->gcwq->lock);
}
/*
@@ -1339,8 +1349,16 @@ static void busy_worker_rebind_fn(struct work_struct *work)
struct worker *worker = container_of(work, struct worker, rebind_work);
struct global_cwq *gcwq = worker->pool->gcwq;
- if (worker_maybe_bind_and_lock(worker))
- worker_clr_flags(worker, WORKER_REBIND);
+ worker_maybe_bind_and_lock(worker);
+
+ /*
+ * %WORKER_REBIND must be cleared even if the above binding failed;
+ * otherwise, we may confuse the next CPU_UP cycle or oops / get
+ * stuck by calling idle_worker_rebind() prematurely. If CPU went
+ * down again inbetween, %WORKER_UNBOUND would be set, so clearing
+ * %WORKER_REBIND is always safe.
+ */
+ worker_clr_flags(worker, WORKER_REBIND);
spin_unlock_irq(&gcwq->lock);
}
@@ -1396,12 +1414,15 @@ retry:
/* set REBIND and kick idle ones, we'll wait for these later */
for_each_worker_pool(pool, gcwq) {
list_for_each_entry(worker, &pool->idle_list, entry) {
+ unsigned long worker_flags = worker->flags;
+
if (worker->flags & WORKER_REBIND)
continue;
- /* morph UNBOUND to REBIND */
- worker->flags &= ~WORKER_UNBOUND;
- worker->flags |= WORKER_REBIND;
+ /* morph UNBOUND to REBIND atomically */
+ worker_flags &= ~WORKER_UNBOUND;
+ worker_flags |= WORKER_REBIND;
+ ACCESS_ONCE(worker->flags) = worker_flags;
idle_rebind.cnt++;
worker->idle_rebind = &idle_rebind;
@@ -1419,25 +1440,15 @@ retry:
goto retry;
}
- /*
- * All idle workers are rebound and waiting for %WORKER_REBIND to
- * be cleared inside idle_worker_rebind(). Clear and release.
- * Clearing %WORKER_REBIND from this foreign context is safe
- * because these workers are still guaranteed to be idle.
- */
- for_each_worker_pool(pool, gcwq)
- list_for_each_entry(worker, &pool->idle_list, entry)
- worker->flags &= ~WORKER_REBIND;
-
- wake_up_all(&gcwq->rebind_hold);
-
- /* rebind busy workers */
+ /* all idle workers are rebound, rebind busy workers */
for_each_busy_worker(worker, i, pos, gcwq) {
struct work_struct *rebind_work = &worker->rebind_work;
+ unsigned long worker_flags = worker->flags;
- /* morph UNBOUND to REBIND */
- worker->flags &= ~WORKER_UNBOUND;
- worker->flags |= WORKER_REBIND;
+ /* morph UNBOUND to REBIND atomically */
+ worker_flags &= ~WORKER_UNBOUND;
+ worker_flags |= WORKER_REBIND;
+ ACCESS_ONCE(worker->flags) = worker_flags;
if (test_and_set_bit(WORK_STRUCT_PENDING_BIT,
work_data_bits(rebind_work)))
@@ -1449,6 +1460,34 @@ retry:
worker->scheduled.next,
work_color_to_flags(WORK_NO_COLOR));
}
+
+ /*
+ * All idle workers are rebound and waiting for %WORKER_REBIND to
+ * be cleared inside idle_worker_rebind(). Clear and release.
+ * Clearing %WORKER_REBIND from this foreign context is safe
+ * because these workers are still guaranteed to be idle.
+ *
+ * We need to make sure all idle workers passed WORKER_REBIND wait
+ * in idle_worker_rebind() before returning; otherwise, workers can
+ * get stuck at the wait if hotplug cycle repeats.
+ */
+ idle_rebind.cnt = 1;
+ INIT_COMPLETION(idle_rebind.done);
+
+ for_each_worker_pool(pool, gcwq) {
+ list_for_each_entry(worker, &pool->idle_list, entry) {
+ worker->flags &= ~WORKER_REBIND;
+ idle_rebind.cnt++;
+ }
+ }
+
+ wake_up_all(&gcwq->rebind_hold);
+
+ if (--idle_rebind.cnt) {
+ spin_unlock_irq(&gcwq->lock);
+ wait_for_completion(&idle_rebind.done);
+ spin_lock_irq(&gcwq->lock);
+ }
}
static struct worker *alloc_worker(void)
@@ -1794,9 +1833,45 @@ static bool manage_workers(struct worker *worker)
struct worker_pool *pool = worker->pool;
bool ret = false;
- if (!mutex_trylock(&pool->manager_mutex))
+ if (pool->flags & POOL_MANAGING_WORKERS)
return ret;
+ pool->flags |= POOL_MANAGING_WORKERS;
+
+ /*
+ * To simplify both worker management and CPU hotplug, hold off
+ * management while hotplug is in progress. CPU hotplug path can't
+ * grab %POOL_MANAGING_WORKERS to achieve this because that can
+ * lead to idle worker depletion (all become busy thinking someone
+ * else is managing) which in turn can result in deadlock under
+ * extreme circumstances. Use @pool->manager_mutex to synchronize
+ * manager against CPU hotplug.
+ *
+ * manager_mutex would always be free unless CPU hotplug is in
+ * progress. trylock first without dropping @gcwq->lock.
+ */
+ if (unlikely(!mutex_trylock(&pool->manager_mutex))) {
+ spin_unlock_irq(&pool->gcwq->lock);
+ mutex_lock(&pool->manager_mutex);
+ /*
+ * CPU hotplug could have happened while we were waiting
+ * for manager_mutex. Hotplug itself can't handle us
+ * because manager isn't either on idle or busy list, and
+ * @gcwq's state and ours could have deviated.
+ *
+ * As hotplug is now excluded via manager_mutex, we can
+ * simply try to bind. It will succeed or fail depending
+ * on @gcwq's current state. Try it and adjust
+ * %WORKER_UNBOUND accordingly.
+ */
+ if (worker_maybe_bind_and_lock(worker))
+ worker->flags &= ~WORKER_UNBOUND;
+ else
+ worker->flags |= WORKER_UNBOUND;
+
+ ret = true;
+ }
+
pool->flags &= ~POOL_MANAGE_WORKERS;
/*
@@ -1806,6 +1881,7 @@ static bool manage_workers(struct worker *worker)
ret |= maybe_destroy_workers(pool);
ret |= maybe_create_worker(pool);
+ pool->flags &= ~POOL_MANAGING_WORKERS;
mutex_unlock(&pool->manager_mutex);
return ret;
}
@@ -3500,18 +3576,17 @@ static int __devinit workqueue_cpu_down_callback(struct notifier_block *nfb,
#ifdef CONFIG_SMP
struct work_for_cpu {
- struct completion completion;
+ struct work_struct work;
long (*fn)(void *);
void *arg;
long ret;
};
-static int do_work_for_cpu(void *_wfc)
+static void work_for_cpu_fn(struct work_struct *work)
{
- struct work_for_cpu *wfc = _wfc;
+ struct work_for_cpu *wfc = container_of(work, struct work_for_cpu, work);
+
wfc->ret = wfc->fn(wfc->arg);
- complete(&wfc->completion);
- return 0;
}
/**
@@ -3526,19 +3601,11 @@ static int do_work_for_cpu(void *_wfc)
*/
long work_on_cpu(unsigned int cpu, long (*fn)(void *), void *arg)
{
- struct task_struct *sub_thread;
- struct work_for_cpu wfc = {
- .completion = COMPLETION_INITIALIZER_ONSTACK(wfc.completion),
- .fn = fn,
- .arg = arg,
- };
+ struct work_for_cpu wfc = { .fn = fn, .arg = arg };
- sub_thread = kthread_create(do_work_for_cpu, &wfc, "work_for_cpu");
- if (IS_ERR(sub_thread))
- return PTR_ERR(sub_thread);
- kthread_bind(sub_thread, cpu);
- wake_up_process(sub_thread);
- wait_for_completion(&wfc.completion);
+ INIT_WORK_ONSTACK(&wfc.work, work_for_cpu_fn);
+ schedule_work_on(cpu, &wfc.work);
+ flush_work(&wfc.work);
return wfc.ret;
}
EXPORT_SYMBOL_GPL(work_on_cpu);