From aa283f49276e7d840a40fb01eee6de97eaa7e012 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Mon, 10 Mar 2008 15:28:05 -0700 Subject: x86, fpu: lazy allocation of FPU area - v5 Only allocate the FPU area when the application actually uses FPU, i.e., in the first lazy FPU trap. This could save memory for non-fpu using apps. for example: on my system after boot, there are around 300 processes, with only 17 using FPU. Signed-off-by: Suresh Siddha Cc: Arjan van de Ven Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- arch/x86/kernel/process.c | 28 +++++++++++++++++++--------- 1 file changed, 19 insertions(+), 9 deletions(-) (limited to 'arch/x86/kernel/process.c') diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index ead24efbcba0..0e613e7e7b5e 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -5,24 +5,34 @@ #include #include -static struct kmem_cache *task_xstate_cachep; +struct kmem_cache *task_xstate_cachep; int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) { *dst = *src; - dst->thread.xstate = kmem_cache_alloc(task_xstate_cachep, GFP_KERNEL); - if (!dst->thread.xstate) - return -ENOMEM; - WARN_ON((unsigned long)dst->thread.xstate & 15); - memcpy(dst->thread.xstate, src->thread.xstate, xstate_size); + if (src->thread.xstate) { + dst->thread.xstate = kmem_cache_alloc(task_xstate_cachep, + GFP_KERNEL); + if (!dst->thread.xstate) + return -ENOMEM; + WARN_ON((unsigned long)dst->thread.xstate & 15); + memcpy(dst->thread.xstate, src->thread.xstate, xstate_size); + } return 0; } -void free_thread_info(struct thread_info *ti) +void free_thread_xstate(struct task_struct *tsk) { - kmem_cache_free(task_xstate_cachep, ti->task->thread.xstate); - ti->task->thread.xstate = NULL; + if (tsk->thread.xstate) { + kmem_cache_free(task_xstate_cachep, tsk->thread.xstate); + tsk->thread.xstate = NULL; + } +} + +void free_thread_info(struct thread_info *ti) +{ + free_thread_xstate(ti->task); free_pages((unsigned long)(ti), get_order(THREAD_SIZE)); } -- cgit v1.2.3