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| author | Rik van Riel <riel@redhat.com> | 2016-10-14 08:15:31 -0400 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-10-16 11:38:41 +0200 |
| commit | c474e50711aa79b7bd0ea30b44744baca5650375 (patch) | |
| tree | 10ff9375bea326d9f4c3241e01e3b3cf17540544 /arch/x86/kernel/process_64.c | |
| parent | 317b622cb2fda1812d8646e211cdb23dce2564d0 (diff) | |
| download | linux-c474e50711aa79b7bd0ea30b44744baca5650375.tar.bz2 | |
x86/fpu: Split old_fpu & new_fpu handling into separate functions
By moving all of the new_fpu state handling into switch_fpu_finish(),
the code can be simplified some more.
This gets rid of the prefetch, but given the size of the FPU register
state on modern CPUs, and the amount of work done by __switch_to()
inbetween both functions, the value of a single cache line prefetch
seems somewhat dubious anyway.
Signed-off-by: Rik van Riel <riel@redhat.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1476447331-21566-3-git-send-email-riel@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/process_64.c')
| -rw-r--r-- | arch/x86/kernel/process_64.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index ee944bd2310d..705669efb762 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -264,9 +264,8 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) int cpu = smp_processor_id(); struct tss_struct *tss = &per_cpu(cpu_tss, cpu); unsigned prev_fsindex, prev_gsindex; - fpu_switch_t fpu_switch; - fpu_switch = switch_fpu_prepare(prev_fpu, next_fpu, cpu); + switch_fpu_prepare(prev_fpu, cpu); /* We must save %fs and %gs before load_TLS() because * %fs and %gs may be cleared by load_TLS(). @@ -416,7 +415,7 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) prev->gsbase = 0; prev->gsindex = prev_gsindex; - switch_fpu_finish(next_fpu, fpu_switch); + switch_fpu_finish(next_fpu, cpu); /* * Switch the PDA and FPU contexts. |