diff options
Diffstat (limited to 'arch/i386')
-rw-r--r-- | arch/i386/kernel/process.c | 12 | ||||
-rw-r--r-- | arch/i386/kernel/traps.c | 3 |
2 files changed, 14 insertions, 1 deletions
diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c index dd53c58f64f1..ae924c416b68 100644 --- a/arch/i386/kernel/process.c +++ b/arch/i386/kernel/process.c | |||
@@ -648,6 +648,11 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas | |||
648 | 648 | ||
649 | __unlazy_fpu(prev_p); | 649 | __unlazy_fpu(prev_p); |
650 | 650 | ||
651 | |||
652 | /* we're going to use this soon, after a few expensive things */ | ||
653 | if (next_p->fpu_counter > 5) | ||
654 | prefetch(&next->i387.fxsave); | ||
655 | |||
651 | /* | 656 | /* |
652 | * Reload esp0. | 657 | * Reload esp0. |
653 | */ | 658 | */ |
@@ -697,6 +702,13 @@ struct task_struct fastcall * __switch_to(struct task_struct *prev_p, struct tas | |||
697 | 702 | ||
698 | disable_tsc(prev_p, next_p); | 703 | disable_tsc(prev_p, next_p); |
699 | 704 | ||
705 | /* If the task has used fpu the last 5 timeslices, just do a full | ||
706 | * restore of the math state immediately to avoid the trap; the | ||
707 | * chances of needing FPU soon are obviously high now | ||
708 | */ | ||
709 | if (next_p->fpu_counter > 5) | ||
710 | math_state_restore(); | ||
711 | |||
700 | return prev_p; | 712 | return prev_p; |
701 | } | 713 | } |
702 | 714 | ||
diff --git a/arch/i386/kernel/traps.c b/arch/i386/kernel/traps.c index f9bb1f89d687..4a6fa2837df2 100644 --- a/arch/i386/kernel/traps.c +++ b/arch/i386/kernel/traps.c | |||
@@ -1118,7 +1118,7 @@ fastcall unsigned long patch_espfix_desc(unsigned long uesp, | |||
1118 | * Must be called with kernel preemption disabled (in this case, | 1118 | * Must be called with kernel preemption disabled (in this case, |
1119 | * local interrupts are disabled at the call-site in entry.S). | 1119 | * local interrupts are disabled at the call-site in entry.S). |
1120 | */ | 1120 | */ |
1121 | asmlinkage void math_state_restore(struct pt_regs regs) | 1121 | asmlinkage void math_state_restore(void) |
1122 | { | 1122 | { |
1123 | struct thread_info *thread = current_thread_info(); | 1123 | struct thread_info *thread = current_thread_info(); |
1124 | struct task_struct *tsk = thread->task; | 1124 | struct task_struct *tsk = thread->task; |
@@ -1128,6 +1128,7 @@ asmlinkage void math_state_restore(struct pt_regs regs) | |||
1128 | init_fpu(tsk); | 1128 | init_fpu(tsk); |
1129 | restore_fpu(tsk); | 1129 | restore_fpu(tsk); |
1130 | thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */ | 1130 | thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */ |
1131 | tsk->fpu_counter++; | ||
1131 | } | 1132 | } |
1132 | 1133 | ||
1133 | #ifndef CONFIG_MATH_EMULATION | 1134 | #ifndef CONFIG_MATH_EMULATION |