diff options
Diffstat (limited to 'arch/x86/kernel/process_64.c')
-rw-r--r-- | arch/x86/kernel/process_64.c | 23 |
1 files changed, 0 insertions, 23 deletions
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index 9b9fe4a85c87..992b4e542bc3 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c | |||
@@ -386,18 +386,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) | |||
386 | int cpu = smp_processor_id(); | 386 | int cpu = smp_processor_id(); |
387 | struct tss_struct *tss = &per_cpu(init_tss, cpu); | 387 | struct tss_struct *tss = &per_cpu(init_tss, cpu); |
388 | unsigned fsindex, gsindex; | 388 | unsigned fsindex, gsindex; |
389 | bool preload_fpu; | ||
390 | |||
391 | /* | ||
392 | * If the task has used fpu the last 5 timeslices, just do a full | ||
393 | * restore of the math state immediately to avoid the trap; the | ||
394 | * chances of needing FPU soon are obviously high now | ||
395 | */ | ||
396 | preload_fpu = tsk_used_math(next_p) && next_p->fpu_counter > 5; | ||
397 | |||
398 | /* we're going to use this soon, after a few expensive things */ | ||
399 | if (preload_fpu) | ||
400 | prefetch(next->fpu.state); | ||
401 | 389 | ||
402 | /* | 390 | /* |
403 | * Reload esp0, LDT and the page table pointer: | 391 | * Reload esp0, LDT and the page table pointer: |
@@ -430,10 +418,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) | |||
430 | /* Must be after DS reload */ | 418 | /* Must be after DS reload */ |
431 | __unlazy_fpu(prev_p); | 419 | __unlazy_fpu(prev_p); |
432 | 420 | ||
433 | /* Make sure cpu is ready for new context */ | ||
434 | if (preload_fpu) | ||
435 | clts(); | ||
436 | |||
437 | /* | 421 | /* |
438 | * Leave lazy mode, flushing any hypercalls made here. | 422 | * Leave lazy mode, flushing any hypercalls made here. |
439 | * This must be done before restoring TLS segments so | 423 | * This must be done before restoring TLS segments so |
@@ -492,13 +476,6 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p) | |||
492 | task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV)) | 476 | task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV)) |
493 | __switch_to_xtra(prev_p, next_p, tss); | 477 | __switch_to_xtra(prev_p, next_p, tss); |
494 | 478 | ||
495 | /* | ||
496 | * Preload the FPU context, now that we've determined that the | ||
497 | * task is likely to be using it. | ||
498 | */ | ||
499 | if (preload_fpu) | ||
500 | __math_state_restore(); | ||
501 | |||
502 | return prev_p; | 479 | return prev_p; |
503 | } | 480 | } |
504 | 481 | ||