diff options
| author | Ingo Molnar <mingo@kernel.org> | 2015-04-23 17:08:41 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-05-19 15:47:26 +0200 |
| commit | eb6a3251bfe34f327570993e9a95dbf3a592b912 (patch) | |
| tree | 2d0f44201bcef45fc324a7c11c85bf7449dad2de /arch/x86/include/asm/fpu | |
| parent | ca6787ba0fcc875cfb06dc2a538ac23210b7d251 (diff) | |
x86/fpu: Remove task_disable_lazy_fpu_restore()
Replace task_disable_lazy_fpu_restore() with easier to read
open-coded uses: we already update the fpu->last_cpu field
explicitly in other cases.
(This also removes yet another task_struct using FPU method.)
Better explain the fpu::last_cpu field in the structure definition.
Reviewed-by: Borislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.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>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/fpu')
| -rw-r--r-- | arch/x86/include/asm/fpu/types.h | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu/types.h b/arch/x86/include/asm/fpu/types.h index f6317d9aa808..cad1c37d9ea2 100644 --- a/arch/x86/include/asm/fpu/types.h +++ b/arch/x86/include/asm/fpu/types.h @@ -125,7 +125,18 @@ union thread_xstate { }; struct fpu { + /* + * Records the last CPU on which this context was loaded into + * FPU registers. (In the lazy-switching case we might be + * able to reuse FPU registers across multiple context switches + * this way, if no intermediate task used the FPU.) + * + * A value of -1 is used to indicate that the FPU state in context + * memory is newer than the FPU state in registers, and that the + * FPU state should be reloaded next time the task is run. + */ unsigned int last_cpu; + unsigned int has_fpu; union thread_xstate *state; /* |