From 61c4628b538608c1a85211ed8438136adfeb9a95 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Mon, 10 Mar 2008 15:28:04 -0700 Subject: x86, fpu: split FPU state from task struct - v5 Split the FPU save area from the task struct. This allows easy migration of FPU context, and it's generally cleaner. It also allows the following two optimizations: 1) only allocate when the application actually uses FPU, so in the first lazy FPU trap. This could save memory for non-fpu using apps. Next patch does this lazy allocation. 2) allocate the right size for the actual cpu rather than 512 bytes always. Patches enabling xsave/xrstor support (coming shortly) will take advantage of this. Signed-off-by: Suresh Siddha Signed-off-by: Arjan van de Ven Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/fork.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) (limited to 'kernel/fork.c') diff --git a/kernel/fork.c b/kernel/fork.c index 9c042f90157..44a18192c42 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -132,6 +132,10 @@ void __put_task_struct(struct task_struct *tsk) free_task(tsk); } +void __attribute__((weak)) arch_task_cache_init(void) +{ +} + void __init fork_init(unsigned long mempages) { #ifndef __HAVE_ARCH_TASK_STRUCT_ALLOCATOR @@ -144,6 +148,9 @@ void __init fork_init(unsigned long mempages) ARCH_MIN_TASKALIGN, SLAB_PANIC, NULL); #endif + /* do the arch specific task caches init */ + arch_task_cache_init(); + /* * The default maximum number of threads is set to a safe * value: the thread structures can take up at most half @@ -163,6 +170,13 @@ void __init fork_init(unsigned long mempages) init_task.signal->rlim[RLIMIT_NPROC]; } +int __attribute__((weak)) arch_dup_task_struct(struct task_struct *dst, + struct task_struct *src) +{ + *dst = *src; + return 0; +} + static struct task_struct *dup_task_struct(struct task_struct *orig) { struct task_struct *tsk; @@ -181,15 +195,15 @@ static struct task_struct *dup_task_struct(struct task_struct *orig) return NULL; } - *tsk = *orig; + err = arch_dup_task_struct(tsk, orig); + if (err) + goto out; + tsk->stack = ti; err = prop_local_init_single(&tsk->dirties); - if (err) { - free_thread_info(ti); - free_task_struct(tsk); - return NULL; - } + if (err) + goto out; setup_thread_stack(tsk, orig); @@ -205,6 +219,11 @@ static struct task_struct *dup_task_struct(struct task_struct *orig) #endif tsk->splice_pipe = NULL; return tsk; + +out: + free_thread_info(ti); + free_task_struct(tsk); + return NULL; } #ifdef CONFIG_MMU -- cgit v1.2.3 From 2adee9b30d1382fba97825b9c50e4f50a0117c36 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Wed, 16 Apr 2008 10:25:35 +0200 Subject: x86: fpu xstate split fix Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- include/asm-x86/thread_info.h | 1 + kernel/fork.c | 10 +++++++--- 2 files changed, 8 insertions(+), 3 deletions(-) (limited to 'kernel/fork.c') diff --git a/include/asm-x86/thread_info.h b/include/asm-x86/thread_info.h index 407b88c170d..77244f17993 100644 --- a/include/asm-x86/thread_info.h +++ b/include/asm-x86/thread_info.h @@ -9,5 +9,6 @@ extern void arch_task_cache_init(void); extern void free_thread_info(struct thread_info *ti); extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src); +#define arch_task_cache_init arch_task_cache_init #endif #endif /* _ASM_X86_THREAD_INFO_H */ diff --git a/kernel/fork.c b/kernel/fork.c index 44a18192c42..89fe414645e 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -132,9 +132,13 @@ void __put_task_struct(struct task_struct *tsk) free_task(tsk); } -void __attribute__((weak)) arch_task_cache_init(void) -{ -} +/* + * macro override instead of weak attribute alias, to workaround + * gcc 4.1.0 and 4.1.1 bugs with weak attribute and empty functions. + */ +#ifndef arch_task_cache_init +#define arch_task_cache_init() +#endif void __init fork_init(unsigned long mempages) { -- cgit v1.2.3