From db2dcb4f91d5fec5c346a82c309187ee821e2495 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Tue, 20 Jan 2015 13:00:46 +0000 Subject: [PATCH] irqflags: Fix (at least latent) code generation issue The conditional in local_irq_restore() otherwise can cause code bloat (the if and else blocks may get translated into separate code paths despite the generated code being identical, dependent on compiler internal heuristics). Note that this adjustment gets the code in sync with the comment preceding it (which was slightly wrong from at least from 2.6.37 onwards). The code bloat was observed in reality with an experimental x86 patch. Signed-off-by: Jan Beulich Cc: Peter Zijlstra Cc: Steven Rostedt Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/54BE5F8E02000078000570A7@mail.emea.novell.com Signed-off-by: Ingo Molnar --- include/linux/irqflags.h | 43 ++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 21 deletions(-) diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h index d176d658fe25..5dd1272d1ab2 100644 --- a/include/linux/irqflags.h +++ b/include/linux/irqflags.h @@ -85,7 +85,7 @@ * The local_irq_*() APIs are equal to the raw_local_irq*() * if !TRACE_IRQFLAGS. */ -#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT +#ifdef CONFIG_TRACE_IRQFLAGS #define local_irq_enable() \ do { trace_hardirqs_on(); raw_local_irq_enable(); } while (0) #define local_irq_disable() \ @@ -107,22 +107,6 @@ raw_local_irq_restore(flags); \ } \ } while (0) -#define local_save_flags(flags) \ - do { \ - raw_local_save_flags(flags); \ - } while (0) - -#define irqs_disabled_flags(flags) \ - ({ \ - raw_irqs_disabled_flags(flags); \ - }) - -#define irqs_disabled() \ - ({ \ - unsigned long _flags; \ - raw_local_save_flags(_flags); \ - raw_irqs_disabled_flags(_flags); \ - }) #define safe_halt() \ do { \ @@ -131,7 +115,7 @@ } while (0) -#else /* !CONFIG_TRACE_IRQFLAGS_SUPPORT */ +#else /* !CONFIG_TRACE_IRQFLAGS */ #define local_irq_enable() do { raw_local_irq_enable(); } while (0) #define local_irq_disable() do { raw_local_irq_disable(); } while (0) @@ -140,11 +124,28 @@ raw_local_irq_save(flags); \ } while (0) #define local_irq_restore(flags) do { raw_local_irq_restore(flags); } while (0) -#define local_save_flags(flags) do { raw_local_save_flags(flags); } while (0) -#define irqs_disabled() (raw_irqs_disabled()) -#define irqs_disabled_flags(flags) (raw_irqs_disabled_flags(flags)) #define safe_halt() do { raw_safe_halt(); } while (0) +#endif /* CONFIG_TRACE_IRQFLAGS */ + +#define local_save_flags(flags) raw_local_save_flags(flags) + +/* + * Some architectures don't define arch_irqs_disabled(), so even if either + * definition would be fine we need to use different ones for the time being + * to avoid build issues. + */ +#ifdef CONFIG_TRACE_IRQFLAGS_SUPPORT +#define irqs_disabled() \ + ({ \ + unsigned long _flags; \ + raw_local_save_flags(_flags); \ + raw_irqs_disabled_flags(_flags); \ + }) +#else /* !CONFIG_TRACE_IRQFLAGS_SUPPORT */ +#define irqs_disabled() raw_irqs_disabled() #endif /* CONFIG_TRACE_IRQFLAGS_SUPPORT */ +#define irqs_disabled_flags(flags) raw_irqs_disabled_flags(flags) + #endif -- 2.20.1