diff options
| author | Ingo Molnar <mingo@kernel.org> | 2015-07-17 12:28:12 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-07-18 03:42:51 +0200 |
| commit | 5aaeb5c01c5b6c0be7b7aadbf3ace9f3a4458c3d (patch) | |
| tree | 8cf45cdd6647d1067d94aaad64598a7728f15d6b /arch/x86 | |
| parent | 0c8c0f03e3a292e031596484275c14cf39c0ab7a (diff) | |
x86/fpu, sched: Introduce CONFIG_ARCH_WANTS_DYNAMIC_TASK_STRUCT and use it on x86
Don't burden architectures without dynamic task_struct sizing
with the overhead of dynamic sizing.
Also optimize the x86 code a bit by caching task_struct_size.
Acked-and-Tested-by: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave@sr71.net>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1437128892-9831-3-git-send-email-mingo@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/fpu/init.c | 17 | ||||
| -rw-r--r-- | arch/x86/kernel/process.c | 2 |
3 files changed, 11 insertions, 9 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 3dbb7e7909ca..b3a1a5d77d92 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -41,6 +41,7 @@ config X86 select ARCH_USE_CMPXCHG_LOCKREF if X86_64 select ARCH_USE_QUEUED_RWLOCKS select ARCH_USE_QUEUED_SPINLOCKS + select ARCH_WANTS_DYNAMIC_TASK_STRUCT select ARCH_WANT_FRAME_POINTERS select ARCH_WANT_IPC_PARSE_VERSION if X86_32 select ARCH_WANT_OPTIONAL_GPIOLIB diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c index deacbfa6b33e..0b39173dd971 100644 --- a/arch/x86/kernel/fpu/init.c +++ b/arch/x86/kernel/fpu/init.c @@ -4,6 +4,8 @@ #include <asm/fpu/internal.h> #include <asm/tlbflush.h> +#include <linux/sched.h> + /* * Initialize the TS bit in CR0 according to the style of context-switches * we are using: @@ -136,16 +138,14 @@ static void __init fpu__init_system_generic(void) unsigned int xstate_size; EXPORT_SYMBOL_GPL(xstate_size); -#define CHECK_MEMBER_AT_END_OF(TYPE, MEMBER) \ - BUILD_BUG_ON((sizeof(TYPE) - \ - offsetof(TYPE, MEMBER) - \ - sizeof(((TYPE *)0)->MEMBER)) > \ - 0) \ +/* Enforce that 'MEMBER' is the last field of 'TYPE': */ +#define CHECK_MEMBER_AT_END_OF(TYPE, MEMBER) \ + BUILD_BUG_ON(sizeof(TYPE) != offsetofend(TYPE, MEMBER)) /* - * We append the 'struct fpu' to the task_struct. + * We append the 'struct fpu' to the task_struct: */ -int __weak arch_task_struct_size(void) +static void __init fpu__init_task_struct_size(void) { int task_size = sizeof(struct task_struct); @@ -172,7 +172,7 @@ int __weak arch_task_struct_size(void) CHECK_MEMBER_AT_END_OF(struct thread_struct, fpu); CHECK_MEMBER_AT_END_OF(struct task_struct, thread); - return task_size; + arch_task_struct_size = task_size; } /* @@ -326,6 +326,7 @@ void __init fpu__init_system(struct cpuinfo_x86 *c) fpu__init_system_generic(); fpu__init_system_xstate_size_legacy(); fpu__init_system_xstate(); + fpu__init_task_struct_size(); fpu__init_system_ctx_switch(); } diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 975420eac105..397688beed4b 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -81,7 +81,7 @@ EXPORT_SYMBOL_GPL(idle_notifier_unregister); */ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) { - memcpy(dst, src, arch_task_struct_size()); + memcpy(dst, src, arch_task_struct_size); return fpu__copy(&dst->thread.fpu, &src->thread.fpu); } |