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2010-08-09mm: use for_each_online_cpu() in vmstatMinchan Kim
The sum_vm_events passes cpumask for for_each_cpu(). But it's useless since we have for_each_online_cpu. Althougth it's tirival overhead, it's not good about coding consistency. Let's use for_each_online_cpu instead of for_each_cpu with cpumask argument. Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Christoph Lameter <cl@linux-foundation.org> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: fold __out_of_memory into out_of_memoryDavid Rientjes
__out_of_memory() only has a single caller, so fold it into out_of_memory() and add a comment about locking for its call to oom_kill_process(). Signed-off-by: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: remove constraint argument from select_bad_process and __out_of_memoryDavid Rientjes
select_bad_process() and __out_of_memory() doe not need their enum oom_constraint arguments: it's possible to pass a NULL nodemask if constraint == CONSTRAINT_MEMORY_POLICY in the caller, out_of_memory(). Signed-off-by: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: rename try_set_zone_oom() to try_set_zonelist_oom()Minchan Kim
We have been used naming try_set_zone_oom and clear_zonelist_oom. The role of functions is to lock of zonelist for preventing parallel OOM. So clear_zonelist_oom makes sense but try_set_zone_oome is rather awkward and unmatched with clear_zonelist_oom. Let's change it with try_set_zonelist_oom. Signed-off-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: remove unnecessary code and cleanupDavid Rientjes
Remove the redundancy in __oom_kill_task() since: - init can never be passed to this function: it will never be PF_EXITING or selectable from select_bad_process(), and - it will never be passed a task from oom_kill_task() without an ->mm and we're unconcerned about detachment from exiting tasks, there's no reason to protect them against SIGKILL or access to memory reserves. Also moves the kernel log message to a higher level since the verbosity is not always emitted here; we need not print an error message if an exiting task is given a longer timeslice. __oom_kill_task() only has a single caller, so it can be merged into that function at the same time. Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: remove special handling for pagefault oomsDavid Rientjes
It is possible to remove the special pagefault oom handler by simply oom locking all system zones and then calling directly into out_of_memory(). All populated zones must have ZONE_OOM_LOCKED set, otherwise there is a parallel oom killing in progress that will lead to eventual memory freeing so it's not necessary to needlessly kill another task. The context in which the pagefault is allocating memory is unknown to the oom killer, so this is done on a system-wide level. If a task has already been oom killed and hasn't fully exited yet, this will be a no-op since select_bad_process() recognizes tasks across the system with TIF_MEMDIE set. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Nick Piggin <npiggin@suse.de> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: extract panic helper functionDavid Rientjes
There are various points in the oom killer where the kernel must determine whether to panic or not. It's better to extract this to a helper function to remove all the confusion as to its semantics. Also fix a call to dump_header() where tasklist_lock is not read- locked, as required. There's no functional change with this patch. Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: avoid oom killer for lowmem allocationsDavid Rientjes
If memory has been depleted in lowmem zones even with the protection afforded to it by /proc/sys/vm/lowmem_reserve_ratio, it is unlikely that killing current users will help. The memory is either reclaimable (or migratable) already, in which case we should not invoke the oom killer at all, or it is pinned by an application for I/O. Killing such an application may leave the hardware in an unspecified state and there is no guarantee that it will be able to make a timely exit. Lowmem allocations are now failed in oom conditions when __GFP_NOFAIL is not used so that the task can perhaps recover or try again later. Previously, the heuristic provided some protection for those tasks with CAP_SYS_RAWIO, but this is no longer necessary since we will not be killing tasks for the purposes of ISA allocations. high_zoneidx is gfp_zone(gfp_flags), meaning that ZONE_NORMAL will be the default for all allocations that are not __GFP_DMA, __GFP_DMA32, __GFP_HIGHMEM, and __GFP_MOVABLE on kernels configured to support those flags. Testing for high_zoneidx being less than ZONE_NORMAL will only return true for allocations that have either __GFP_DMA or __GFP_DMA32. Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: enable oom tasklist dump by defaultDavid Rientjes
The oom killer tasklist dump, enabled with the oom_dump_tasks sysctl, is very helpful information in diagnosing why a user's task has been killed. It emits useful information such as each eligible thread's memory usage that can determine why the system is oom, so it should be enabled by default. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: select task from tasklist for mempolicy oomsDavid Rientjes
The oom killer presently kills current whenever there is no more memory free or reclaimable on its mempolicy's nodes. There is no guarantee that current is a memory-hogging task or that killing it will free any substantial amount of memory, however. In such situations, it is better to scan the tasklist for nodes that are allowed to allocate on current's set of nodes and kill the task with the highest badness() score. This ensures that the most memory-hogging task, or the one configured by the user with /proc/pid/oom_adj, is always selected in such scenarios. Signed-off-by: David Rientjes <rientjes@google.com> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: sacrifice child with highest badness score for parentDavid Rientjes
When a task is chosen for oom kill, the oom killer first attempts to sacrifice a child not sharing its parent's memory instead. Unfortunately, this often kills in a seemingly random fashion based on the ordering of the selected task's child list. Additionally, it is not guaranteed at all to free a large amount of memory that we need to prevent additional oom killing in the very near future. Instead, we now only attempt to sacrifice the worst child not sharing its parent's memory, if one exists. The worst child is indicated with the highest badness() score. This serves two advantages: we kill a memory-hogging task more often, and we allow the configurable /proc/pid/oom_adj value to be considered as a factor in which child to kill. Reviewers may observe that the previous implementation would iterate through the children and attempt to kill each until one was successful and then the parent if none were found while the new code simply kills the most memory-hogging task or the parent. Note that the only time oom_kill_task() fails, however, is when a child does not have an mm or has a /proc/pid/oom_adj of OOM_DISABLE. badness() returns 0 for both cases, so the final oom_kill_task() will always succeed. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Nick Piggin <npiggin@suse.de> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: filter tasks not sharing the same cpusetDavid Rientjes
Tasks that do not share the same set of allowed nodes with the task that triggered the oom should not be considered as candidates for oom kill. Tasks in other cpusets with a disjoint set of mems would be unfairly penalized otherwise because of oom conditions elsewhere; an extreme example could unfairly kill all other applications on the system if a single task in a user's cpuset sets itself to OOM_DISABLE and then uses more memory than allowed. Killing tasks outside of current's cpuset rarely would free memory for current anyway. To use a sane heuristic, we must ensure that killing a task would likely free memory for current and avoid needlessly killing others at all costs just because their potential memory freeing is unknown. It is better to kill current than another task needlessly. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Nick Piggin <npiggin@suse.de> Acked-by: Balbir Singh <balbir@linux.vnet.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: avoid sending exiting tasks a SIGKILLDavid Rientjes
It's unnecessary to SIGKILL a task that is already PF_EXITING and can actually cause a NULL pointer dereference of the sighand if it has already been detached. Instead, simply set TIF_MEMDIE so it has access to memory reserves and can quickly exit as the comment implies. Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: give current access to memory reserves if it has been killedDavid Rientjes
It's possible to livelock the page allocator if a thread has mm->mmap_sem and fails to make forward progress because the oom killer selects another thread sharing the same ->mm to kill that cannot exit until the semaphore is dropped. The oom killer will not kill multiple tasks at the same time; each oom killed task must exit before another task may be killed. Thus, if one thread is holding mm->mmap_sem and cannot allocate memory, all threads sharing the same ->mm are blocked from exiting as well. In the oom kill case, that means the thread holding mm->mmap_sem will never free additional memory since it cannot get access to memory reserves and the thread that depends on it with access to memory reserves cannot exit because it cannot acquire the semaphore. Thus, the page allocators livelocks. When the oom killer is called and current happens to have a pending SIGKILL, this patch automatically gives it access to memory reserves and returns. Upon returning to the page allocator, its allocation will hopefully succeed so it can quickly exit and free its memory. If not, the page allocator will fail the allocation if it is not __GFP_NOFAIL. Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: dump_tasks use find_lock_task_mm too fixDavid Rientjes
When find_lock_task_mm() returns a thread other than p in dump_tasks(), its name should be displayed instead. This is the thread that will be targeted by the oom killer, not its mm-less parent. This also allows us to safely dereference task->comm without needing get_task_comm(). While we're here, remove the cast on task_cpu(task) as Andrew suggested. Signed-off-by: David Rientjes <rientjes@google.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: improve commentary in dump_tasks()David Rientjes
The comments in dump_tasks() should be updated to be more clear about why tasks are filtered and how they are filtered by its argument. An unnecessary comment concerning a check for is_global_init() is removed since it isn't of importance. Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: dump_tasks use find_lock_task_mm tooKOSAKI Motohiro
dump_task() should use find_lock_task_mm() too. It is necessary for protecting task-exiting race. dump_tasks() currently filters any task that does not have an attached ->mm since it incorrectly assumes that it must either be in the process of exiting and has detached its memory or that it's a kernel thread; multithreaded tasks may actually have subthreads that have a valid ->mm pointer and thus those threads should actually be displayed. This change finds those threads, if they exist, and emit their information along with the rest of the candidate tasks for kill. Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: introduce find_lock_task_mm() to fix !mm false positivesOleg Nesterov
Almost all ->mm == NULL checks in oom_kill.c are wrong. The current code assumes that the task without ->mm has already released its memory and ignores the process. However this is not necessarily true when this process is multithreaded, other live sub-threads can use this ->mm. - Remove the "if (!p->mm)" check in select_bad_process(), it is just wrong. - Add the new helper, find_lock_task_mm(), which finds the live thread which uses the memory and takes task_lock() to pin ->mm - change oom_badness() to use this helper instead of just checking ->mm != NULL. - As David pointed out, select_bad_process() must never choose the task without ->mm, but no matter what oom_badness() returns the task can be chosen if nothing else has been found yet. Change oom_badness() to return int, change it to return -1 if find_lock_task_mm() fails, and change select_bad_process() to check points >= 0. Note! This patch is not enough, we need more changes. - oom_badness() was fixed, but oom_kill_task() still ignores the task without ->mm - oom_forkbomb_penalty() should use find_lock_task_mm() too, and it also needs other changes to actually find the first first-descendant children This will be addressed later. [kosaki.motohiro@jp.fujitsu.com: use in badness(), __oom_kill_task()] Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: PF_EXITING check should take mm into accountOleg Nesterov
select_bad_process() checks PF_EXITING to detect the task which is going to release its memory, but the logic is very wrong. - a single process P with the dead group leader disables select_bad_process() completely, it will always return ERR_PTR() while P can live forever - if the PF_EXITING task has already released its ->mm it doesn't make sense to expect it is goiing to free more memory (except task_struct/etc) Change the code to ignore the PF_EXITING tasks without ->mm. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: David Rientjes <rientjes@google.com> Cc: Balbir Singh <balbir@in.ibm.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09oom: check PF_KTHREAD instead of !mm to skip kthreadsOleg Nesterov
select_bad_process() thinks a kernel thread can't have ->mm != NULL, this is not true due to use_mm(). Change the code to check PF_KTHREAD. Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: extend KSM refcounts to the anon_vma rootRik van Riel
KSM reference counts can cause an anon_vma to exist after the processe it belongs to have already exited. Because the anon_vma lock now lives in the root anon_vma, we need to ensure that the root anon_vma stays around until after all the "child" anon_vmas have been freed. The obvious way to do this is to have a "child" anon_vma take a reference to the root in anon_vma_fork. When the anon_vma is freed at munmap or process exit, we drop the refcount in anon_vma_unlink and possibly free the root anon_vma. The KSM anon_vma reference count function also needs to be modified to deal with the possibility of freeing 2 levels of anon_vma. The easiest way to do this is to break out the KSM magic and make it generic. When compiling without CONFIG_KSM, this code is compiled out. Signed-off-by: Rik van Riel <riel@redhat.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Tested-by: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: always lock the root (oldest) anon_vmaRik van Riel
Always (and only) lock the root (oldest) anon_vma whenever we do something in an anon_vma. The recently introduced anon_vma scalability is due to the rmap code scanning only the VMAs that need to be scanned. Many common operations still took the anon_vma lock on the root anon_vma, so always taking that lock is not expected to introduce any scalability issues. However, always taking the same lock does mean we only need to take one lock, which means rmap_walk on pages from any anon_vma in the vma is excluded from occurring during an munmap, expand_stack or other operation that needs to exclude rmap_walk and similar functions. Also add the proper locking to vma_adjust. Signed-off-by: Rik van Riel <riel@redhat.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: track the root (oldest) anon_vmaRik van Riel
Track the root (oldest) anon_vma in each anon_vma tree. Because we only take the lock on the root anon_vma, we cannot use the lock on higher-up anon_vmas to lock anything. This makes it impossible to do an indirect lookup of the root anon_vma, since the data structures could go away from under us. However, a direct pointer is safe because the root anon_vma is always the last one that gets freed on munmap or exit, by virtue of the same_vma list order and unlink_anon_vmas walking the list forward. [akpm@linux-foundation.org: fix typo] Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: change direct call of spin_lock(anon_vma->lock) to inline functionRik van Riel
Subsitute a direct call of spin_lock(anon_vma->lock) with an inline function doing exactly the same. This makes it easier to do the substitution to the root anon_vma lock in a following patch. We will deal with the handful of special locks (nested, dec_and_lock, etc) separately. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: rename anon_vma_lock to vma_lock_anon_vmaRik van Riel
Rename anon_vma_lock to vma_lock_anon_vma. This matches the naming style used in page_lock_anon_vma and will come in really handy further down in this patch series. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Tested-by: Larry Woodman <lwoodman@redhat.com> Acked-by: Larry Woodman <lwoodman@redhat.com> Reviewed-by: Minchan Kim <minchan.kim@gmail.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09hugetlb: call mmu notifiers on hugepage cowDoug Doan
When a copy-on-write occurs, we take one of two paths in handle_mm_fault: through handle_pte_fault for normal pages, or through hugetlb_fault for huge pages. In the normal page case, we eventually get to do_wp_page and call mmu notifiers via ptep_clear_flush_notify. There is no callout to the mmmu notifiers in the huge page case. This patch fixes that. Signed-off-by: Doug Doan <dougd@cray.com> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: provide init_mm mm_context initializerHeiko Carstens
Provide an INIT_MM_CONTEXT intializer macro which can be used to statically initialize mm_struct:mm_context of init_mm. This way we can get rid of code which will do the initialization at run time (on s390). In addition the current code can be found at a place where it is not expected. So let's have a common initializer which architectures can use if needed. This is based on a patch from Suzuki Poulose. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Suzuki Poulose <suzuki@in.ibm.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: use ERR_CASTJulia Lawall
Use ERR_CAST(x) rather than ERR_PTR(PTR_ERR(x)). The former makes more clear what is the purpose of the operation, which otherwise looks like a no-op. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ type T; T x; identifier f; @@ T f (...) { <+... - ERR_PTR(PTR_ERR(x)) + x ...+> } @@ expression x; @@ - ERR_PTR(PTR_ERR(x)) + ERR_CAST(x) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-09mm: use memdup_userJulia Lawall
Use memdup_user when user data is immediately copied into the allocated region. The semantic patch that makes this change is as follows: (http://coccinelle.lip6.fr/) // <smpl> @@ expression from,to,size,flag; position p; identifier l1,l2; @@ - to = \(kmalloc@p\|kzalloc@p\)(size,flag); + to = memdup_user(from,size); if ( - to==NULL + IS_ERR(to) || ...) { <+... when != goto l1; - -ENOMEM + PTR_ERR(to) ...+> } - if (copy_from_user(to, from, size) != 0) { - <+... when != goto l2; - -EFAULT - ...+> - } // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-08-06Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/slab-2.6: slub: Allow removal of slab caches during boot Revert "slub: Allow removal of slab caches during boot" slub numa: Fix rare allocation from unexpected node slab: use deferable timers for its periodic housekeeping slub: Use kmem_cache flags to detect if slab is in debugging mode. slub: Allow removal of slab caches during boot slub: Check kasprintf results in kmem_cache_init() SLUB: Constants need UL slub: Use a constant for a unspecified node. SLOB: Free objects to their own list slab: fix caller tracking on !CONFIG_DEBUG_SLAB && CONFIG_TRACING
2010-08-06Merge branch 'x86-mm-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: x86: Ioremap: fix wrong physical address handling in PAT code x86, tlb: Clean up and correct used type x86, iomap: Fix wrong page aligned size calculation in ioremapping code x86, mm: Create symbolic index into address_markers array x86, ioremap: Fix normal ram range check x86, ioremap: Fix incorrect physical address handling in PAE mode x86-64, mm: Initialize VDSO earlier on 64 bits x86, kmmio/mmiotrace: Fix double free of kmmio_fault_pages
2010-08-06Merge branch 'perf-core-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (162 commits) tracing/kprobes: unregister_trace_probe needs to be called under mutex perf: expose event__process function perf events: Fix mmap offset determination perf, powerpc: fsl_emb: Restore setting perf_sample_data.period perf, powerpc: Convert the FSL driver to use local64_t perf tools: Don't keep unreferenced maps when unmaps are detected perf session: Invalidate last_match when removing threads from rb_tree perf session: Free the ref_reloc_sym memory at the right place x86,mmiotrace: Add support for tracing STOS instruction perf, sched migration: Librarize task states and event headers helpers perf, sched migration: Librarize the GUI class perf, sched migration: Make the GUI class client agnostic perf, sched migration: Make it vertically scrollable perf, sched migration: Parameterize cpu height and spacing perf, sched migration: Fix key bindings perf, sched migration: Ignore unhandled task states perf, sched migration: Handle ignored migrate out events perf: New migration tool overview tracing: Drop cpparg() macro perf: Use tracepoint_synchronize_unregister() to flush any pending tracepoint call ... Fix up trivial conflicts in Makefile and drivers/cpufreq/cpufreq.c
2010-08-06Merge branch 'core-rcu-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: Revert "net: Make accesses to ->br_port safe for sparse RCU" mce: convert to rcu_dereference_index_check() net: Make accesses to ->br_port safe for sparse RCU vfs: add fs.h to define struct file lockdep: Add an in_workqueue_context() lockdep-based test function rcu: add __rcu API for later sparse checking rcu: add an rcu_dereference_index_check() tree/tiny rcu: Add debug RCU head objects mm: remove all rcu head initializations fs: remove all rcu head initializations, except on_stack initializations powerpc: remove all rcu head initializations
2010-08-05Merge branch 'for_linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: debug_core,kdb: fix crash when arch does not have single step kgdb,x86: use macro HBP_NUM to replace magic number 4 kgdb,mips: remove unused kgdb_cpu_doing_single_step operations mm,kdb,kgdb: Add a debug reference for the kdb kmap usage KGDB: Remove set but unused newPC ftrace,kdb: Allow dumping a specific cpu's buffer with ftdump ftrace,kdb: Extend kdb to be able to dump the ftrace buffer kgdb,powerpc: Replace hardcoded offset by BREAK_INSTR_SIZE arm,kgdb: Add ability to trap into debugger on notify_die gdbstub: do not directly use dbg_reg_def[] in gdb_cmd_reg_set() gdbstub: Implement gdbserial 'p' and 'P' packets kgdb,arm: Individual register get/set for arm kgdb,mips: Individual register get/set for mips kgdb,x86: Individual register get/set for x86 kgdb,kdb: individual register set and and get API gdbstub: Optimize kgdb's "thread:" response for the gdb serial protocol kgdb: remove custom hex_to_bin()implementation
2010-08-05mm,kdb,kgdb: Add a debug reference for the kdb kmap usageJason Wessel
The kdb kmap should never get used outside of the kernel debugger exception context. Signed-off-by: Jason Wessel<jason.wessel@windriver.com> CC: Andrew Morton <akpm@linux-foundation.org> CC: Ingo Molnar <mingo@elte.hu> CC: linux-mm@kvack.org
2010-08-04Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: allow limited allocation before slab is online percpu: make @dyn_size always mean min dyn_size in first chunk init functions
2010-08-04Merge branches 'slab/fixes', 'slob/fixes', 'slub/cleanups' and 'slub/fixes' ↵Pekka Enberg
into for-linus
2010-08-04Merge branch 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
* 'kvm-updates/2.6.36' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (198 commits) KVM: VMX: Fix host GDT.LIMIT corruption KVM: MMU: using __xchg_spte more smarter KVM: MMU: cleanup spte set and accssed/dirty tracking KVM: MMU: don't atomicly set spte if it's not present KVM: MMU: fix page dirty tracking lost while sync page KVM: MMU: fix broken page accessed tracking with ept enabled KVM: MMU: add missing reserved bits check in speculative path KVM: MMU: fix mmu notifier invalidate handler for huge spte KVM: x86 emulator: fix xchg instruction emulation KVM: x86: Call mask notifiers from pic KVM: x86: never re-execute instruction with enabled tdp KVM: Document KVM_GET_SUPPORTED_CPUID2 ioctl KVM: x86: emulator: inc/dec can have lock prefix KVM: MMU: Eliminate redundant temporaries in FNAME(fetch) KVM: MMU: Validate all gptes during fetch, not just those used for new pages KVM: MMU: Simplify spte fetch() function KVM: MMU: Add gpte_valid() helper KVM: MMU: Add validate_direct_spte() helper KVM: MMU: Add drop_large_spte() helper KVM: MMU: Use __set_spte to link shadow pages ...
2010-08-03slub: Allow removal of slab caches during bootChristoph Lameter
Serialize kmem_cache_create and kmem_cache_destroy using the slub_lock. Only possible after the use of the slub_lock during dynamic dma creation has been removed. Then make sure that the setup of the slab sysfs entries does not race with kmem_cache_create and kmem_cache destroy. If a slab cache is removed before we have setup sysfs then simply skip over the sysfs handling. Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Roland Dreier <rdreier@cisco.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-08-03Revert "slub: Allow removal of slab caches during boot"Pekka Enberg
This reverts commit f5b801ac38a9612b380ee9a75ab1861f0594e79f.
2010-08-02Merge commit 'v2.6.35' into perf/coreIngo Molnar
Conflicts: tools/perf/Makefile tools/perf/util/hist.c Merge reason: Resolve the conflicts and update to latest upstream. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-08-01KVM: Fix a race condition for usage of is_hwpoison_address()Huang Ying
is_hwpoison_address accesses the page table, so the caller must hold current->mm->mmap_sem in read mode. So fix its usage in hva_to_pfn of kvm accordingly. Comment is_hwpoison_address to remind other users. Reported-by: Avi Kivity <avi@redhat.com> Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-08-01KVM: Avoid killing userspace through guest SRAO MCE on unmapped pagesHuang Ying
In common cases, guest SRAO MCE will cause corresponding poisoned page be un-mapped and SIGBUS be sent to QEMU-KVM, then QEMU-KVM will relay the MCE to guest OS. But it is reported that if the poisoned page is accessed in guest after unmapping and before MCE is relayed to guest OS, userspace will be killed. The reason is as follows. Because poisoned page has been un-mapped, guest access will cause guest exit and kvm_mmu_page_fault will be called. kvm_mmu_page_fault can not get the poisoned page for fault address, so kernel and user space MMIO processing is tried in turn. In user MMIO processing, poisoned page is accessed again, then userspace is killed by force_sig_info. To fix the bug, kvm_mmu_page_fault send HWPOISON signal to QEMU-KVM and do not try kernel and user space MMIO processing for poisoned page. [xiao: fix warning introduced by avi] Reported-by: Max Asbock <masbock@linux.vnet.ibm.com> Signed-off-by: Huang Ying <ying.huang@intel.com> Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-07-30mm: fix ia64 crash when gcore reads gate areaHugh Dickins
Debian's ia64 autobuilders have been seeing kernel freeze or reboot when running the gdb testsuite (Debian bug 588574): dannf bisected to 2.6.32 62eede62dafb4a6633eae7ffbeb34c60dba5e7b1 "mm: ZERO_PAGE without PTE_SPECIAL"; and reproduced it with gdb's gcore on a simple target. I'd missed updating the gate_vma handling in __get_user_pages(): that happens to use vm_normal_page() (nowadays failing on the zero page), yet reported success even when it failed to get a page - boom when access_process_vm() tried to copy that to its intermediate buffer. Fix this, resisting cleanups: in particular, leave it for now reporting success when not asked to get any pages - very probably safe to change, but let's not risk it without testing exposure. Why did ia64 crash with 16kB pages, but succeed with 64kB pages? Because setup_gate() pads each 64kB of its gate area with zero pages. Reported-by: Andreas Barth <aba@not.so.argh.org> Bisected-by: dann frazier <dannf@debian.org> Signed-off-by: Hugh Dickins <hughd@google.com> Tested-by: dann frazier <dannf@dannf.org> Cc: stable@kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-07-29slub numa: Fix rare allocation from unexpected nodeChristoph Lameter
The network developers have seen sporadic allocations resulting in objects coming from unexpected NUMA nodes despite asking for objects from a specific node. This is due to get_partial() calling get_any_partial() if partial slabs are exhausted for a node even if a node was specified and therefore one would expect allocations only from the specified node. get_any_partial() sporadically may return a slab from a foreign node to gradually reduce the size of partial lists on remote nodes and thereby reduce total memory use for a slab cache. The behavior is controlled by the remote_defrag_ratio of each cache. Strictly speaking this is permitted behavior since __GFP_THISNODE was not specified for the allocation but it is certain surprising. This patch makes sure that the remote defrag behavior only occurs if no node was specified. Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-07-21Merge branch 'linus' into perf/coreIngo Molnar
Merge reason: Pick up the latest perf fixes. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-07-20x86,nobootmem: make alloc_bootmem_node fall back to other node when 32bit ↵Yinghai Lu
numa is used Borislav Petkov reported his 32bit numa system has problem: [ 0.000000] Reserving total of 4c00 pages for numa KVA remap [ 0.000000] kva_start_pfn ~ 32800 max_low_pfn ~ 375fe [ 0.000000] max_pfn = 238000 [ 0.000000] 8202MB HIGHMEM available. [ 0.000000] 885MB LOWMEM available. [ 0.000000] mapped low ram: 0 - 375fe000 [ 0.000000] low ram: 0 - 375fe000 [ 0.000000] alloc (nid=8 100000 - 7ee00000) (1000000 - ffffffff) 1000 1000 => 34e7000 [ 0.000000] alloc (nid=8 100000 - 7ee00000) (1000000 - ffffffff) 200 40 => 34c9d80 [ 0.000000] alloc (nid=0 100000 - 7ee00000) (1000000 - ffffffffffffffff) 180 40 => 34e6140 [ 0.000000] alloc (nid=1 80000000 - c7e60000) (1000000 - ffffffffffffffff) 240 40 => 80000000 [ 0.000000] BUG: unable to handle kernel paging request at 40000000 [ 0.000000] IP: [<c2c8cff1>] __alloc_memory_core_early+0x147/0x1d6 [ 0.000000] *pdpt = 0000000000000000 *pde = f000ff53f000ff00 ... [ 0.000000] Call Trace: [ 0.000000] [<c2c8b4f8>] ? __alloc_bootmem_node+0x216/0x22f [ 0.000000] [<c2c90c9b>] ? sparse_early_usemaps_alloc_node+0x5a/0x10b [ 0.000000] [<c2c9149e>] ? sparse_init+0x1dc/0x499 [ 0.000000] [<c2c79118>] ? paging_init+0x168/0x1df [ 0.000000] [<c2c780ff>] ? native_pagetable_setup_start+0xef/0x1bb looks like it allocates too much high address for bootmem. Try to cut limit with get_max_mapped() Reported-by: Borislav Petkov <borislav.petkov@amd.com> Tested-by: Conny Seidel <conny.seidel@amd.com> Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: <stable@kernel.org> [2.6.34.x] Cc: Ingo Molnar <mingo@elte.hu> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-07-20mm/vmscan.c: fix mapping use after freeNick Piggin
We need lock_page_nosync() here because we have no reference to the mapping when taking the page lock. Signed-off-by: Nick Piggin <npiggin@suse.de> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mel@csn.ul.ie> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-07-20slab: use deferable timers for its periodic housekeepingArjan van de Ven
slab has a "once every 2 second" timer for its housekeeping. As the number of logical processors is growing, its more and more common that this 2 second timer becomes the primary wakeup source. This patch turns this housekeeping timer into a deferable timer, which means that the timer does not interrupt idle, but just runs at the next event that wakes the cpu up. The impact is that the timer likely runs a bit later, but during the delay no code is running so there's not all that much reason for a difference in housekeeping to occur because of this delay. Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
2010-07-19mm: add context argument to shrinker callbackDave Chinner
The current shrinker implementation requires the registered callback to have global state to work from. This makes it difficult to shrink caches that are not global (e.g. per-filesystem caches). Pass the shrinker structure to the callback so that users can embed the shrinker structure in the context the shrinker needs to operate on and get back to it in the callback via container_of(). Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>