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author | Linus Torvalds <torvalds@linux-foundation.org> | 2013-12-17 12:35:54 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-12-17 12:35:54 -0800 |
commit | dd0508093b79141e0044ca02f0acb6319f69f546 (patch) | |
tree | 5e0116949fd98cfaee9b118b6637203d17fa5dd0 /arch | |
parent | 1070d5ac193af55fd335ef2aacaf03c5fc4ee461 (diff) | |
parent | 9dbdb155532395ba000c5d5d187658b0e17e529f (diff) | |
download | linux-stable-dd0508093b79141e0044ca02f0acb6319f69f546.tar.gz linux-stable-dd0508093b79141e0044ca02f0acb6319f69f546.tar.bz2 linux-stable-dd0508093b79141e0044ca02f0acb6319f69f546.zip |
Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
"Three fixes for scheduler crashes, each triggers in relatively rare,
hardware environment dependent situations"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/fair: Rework sched_fair time accounting
math64: Add mul_u64_u32_shr()
sched: Remove PREEMPT_NEED_RESCHED from generic code
sched: Initialize power_orig for overlapping groups
Diffstat (limited to 'arch')
-rw-r--r-- | arch/x86/Kconfig | 1 | ||||
-rw-r--r-- | arch/x86/include/asm/preempt.h | 11 |
2 files changed, 12 insertions, 0 deletions
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index e903c71f7e69..0952ecd60eca 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -26,6 +26,7 @@ config X86 select HAVE_AOUT if X86_32 select HAVE_UNSTABLE_SCHED_CLOCK select ARCH_SUPPORTS_NUMA_BALANCING + select ARCH_SUPPORTS_INT128 if X86_64 select ARCH_WANTS_PROT_NUMA_PROT_NONE select HAVE_IDE select HAVE_OPROFILE diff --git a/arch/x86/include/asm/preempt.h b/arch/x86/include/asm/preempt.h index 8729723636fd..c8b051933b1b 100644 --- a/arch/x86/include/asm/preempt.h +++ b/arch/x86/include/asm/preempt.h @@ -8,6 +8,12 @@ DECLARE_PER_CPU(int, __preempt_count); /* + * We use the PREEMPT_NEED_RESCHED bit as an inverted NEED_RESCHED such + * that a decrement hitting 0 means we can and should reschedule. + */ +#define PREEMPT_ENABLED (0 + PREEMPT_NEED_RESCHED) + +/* * We mask the PREEMPT_NEED_RESCHED bit so as not to confuse all current users * that think a non-zero value indicates we cannot preempt. */ @@ -74,6 +80,11 @@ static __always_inline void __preempt_count_sub(int val) __this_cpu_add_4(__preempt_count, -val); } +/* + * Because we keep PREEMPT_NEED_RESCHED set when we do _not_ need to reschedule + * a decrement which hits zero means we have no preempt_count and should + * reschedule. + */ static __always_inline bool __preempt_count_dec_and_test(void) { GEN_UNARY_RMWcc("decl", __preempt_count, __percpu_arg(0), "e"); |