Messages in this thread Patch in this message | | | Date | Thu, 13 Jun 2019 15:54:48 +0200 | From | Peter Zijlstra <> | Subject | [PATCH v2 3/5] x86/percpu, x86/irq: Relax {set,get}_irq_regs() |
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Nadav reported that since the this_cpu_*() ops got asm-volatile constraints on, code generation suffered for do_IRQ(), but since this is all with IRQs disabled we can use __this_cpu_*().
smp_x86_platform_ipi 234 222 -12,+0 smp_kvm_posted_intr_ipi 74 66 -8,+0 smp_kvm_posted_intr_wakeup_ipi 86 78 -8,+0 smp_apic_timer_interrupt 292 284 -8,+0 smp_kvm_posted_intr_nested_ipi 74 66 -8,+0 do_IRQ 195 187 -8,+0
Reported-by: Nadav Amit <nadav.amit@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> --- arch/x86/include/asm/irq_regs.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/x86/include/asm/irq_regs.h +++ b/arch/x86/include/asm/irq_regs.h @@ -16,7 +16,7 @@ DECLARE_PER_CPU(struct pt_regs *, irq_re static inline struct pt_regs *get_irq_regs(void) { - return this_cpu_read(irq_regs); + return __this_cpu_read(irq_regs); } static inline struct pt_regs *set_irq_regs(struct pt_regs *new_regs) @@ -24,7 +24,7 @@ static inline struct pt_regs *set_irq_re struct pt_regs *old_regs; old_regs = get_irq_regs(); - this_cpu_write(irq_regs, new_regs); + __this_cpu_write(irq_regs, new_regs); return old_regs; }
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