From: Paul Mackerras Impact: build fix for powerpc Commit bd753921015e7905 ("perf_counter: software counter event infrastructure") introduced a use of TIF_PERF_COUNTERS into the core perfcounter code. This breaks the build on powerpc because we use a flag in a per-cpu area to signal wakeups on powerpc rather than a thread_info flag, because the thread_info flags have to be manipulated with atomic operations and are thus slower than per-cpu flags. This fixes the by changing the core to use an abstracted set_perf_counter_pending() function, which is defined on x86 to set the TIF_PERF_COUNTERS flag and on powerpc to set the per-cpu flag (paca->perf_counter_pending). It changes the previous powerpc definition of set_perf_counter_pending to not take an argument and adds a clear_perf_counter_pending, so as to simplify the definition on x86. On x86, set_perf_counter_pending() is defined as a macro. Defining it as a static inline in arch/x86/include/asm/perf_counters.h causes compile failures because gets included early in , and the definitions of set_tsk_thread_flag etc. are therefore not available in . (On powerpc this problem is avoided by defining set_perf_counter_pending etc. in .) Signed-off-by: Paul Mackerras Signed-off-by: Peter Zijlstra --- arch/powerpc/include/asm/hw_irq.h | 14 +++++++++++--- arch/powerpc/kernel/irq.c | 11 +++-------- arch/powerpc/kernel/perf_counter.c | 3 +-- arch/x86/include/asm/perf_counter.h | 3 +++ kernel/perf_counter.c | 2 +- 5 files changed, 19 insertions(+), 14 deletions(-) Index: linux-2.6/arch/powerpc/include/asm/hw_irq.h =================================================================== --- linux-2.6.orig/arch/powerpc/include/asm/hw_irq.h +++ linux-2.6/arch/powerpc/include/asm/hw_irq.h @@ -142,10 +142,17 @@ static inline unsigned long get_perf_cou return x; } -static inline void set_perf_counter_pending(int x) +static inline void set_perf_counter_pending(void) { asm volatile("stb %0,%1(13)" : : - "r" (x), + "r" (1), + "i" (offsetof(struct paca_struct, perf_counter_pending))); +} + +static inline void clear_perf_counter_pending(void) +{ + asm volatile("stb %0,%1(13)" : : + "r" (0), "i" (offsetof(struct paca_struct, perf_counter_pending))); } @@ -158,7 +165,8 @@ static inline unsigned long get_perf_cou return 0; } -static inline void set_perf_counter_pending(int x) {} +static inline void set_perf_counter_pending(void) {} +static inline void clear_perf_counter_pending(void) {} static inline void perf_counter_do_pending(void) {} #endif /* CONFIG_PERF_COUNTERS */ Index: linux-2.6/arch/powerpc/kernel/irq.c =================================================================== --- linux-2.6.orig/arch/powerpc/kernel/irq.c +++ linux-2.6/arch/powerpc/kernel/irq.c @@ -104,13 +104,6 @@ static inline notrace void set_soft_enab : : "r" (enable), "i" (offsetof(struct paca_struct, soft_enabled))); } -#ifdef CONFIG_PERF_COUNTERS -notrace void __weak perf_counter_do_pending(void) -{ - set_perf_counter_pending(0); -} -#endif - notrace void raw_local_irq_restore(unsigned long en) { /* @@ -142,8 +135,10 @@ notrace void raw_local_irq_restore(unsig iseries_handle_interrupts(); } - if (get_perf_counter_pending()) + if (get_perf_counter_pending()) { + clear_perf_counter_pending(); perf_counter_do_pending(); + } /* * if (get_paca()->hard_enabled) return; Index: linux-2.6/arch/powerpc/kernel/perf_counter.c =================================================================== --- linux-2.6.orig/arch/powerpc/kernel/perf_counter.c +++ linux-2.6/arch/powerpc/kernel/perf_counter.c @@ -653,7 +653,6 @@ void perf_counter_do_pending(void) struct cpu_hw_counters *cpuhw = &__get_cpu_var(cpu_hw_counters); struct perf_counter *counter; - set_perf_counter_pending(0); for (i = 0; i < cpuhw->n_counters; ++i) { counter = cpuhw->counter[i]; if (counter && counter->wakeup_pending) { @@ -811,7 +810,7 @@ static void perf_counter_interrupt(struc perf_counter_do_pending(); irq_exit(); } else { - set_perf_counter_pending(1); + set_perf_counter_pending(); } } } Index: linux-2.6/arch/x86/include/asm/perf_counter.h =================================================================== --- linux-2.6.orig/arch/x86/include/asm/perf_counter.h +++ linux-2.6/arch/x86/include/asm/perf_counter.h @@ -84,6 +84,9 @@ union cpuid10_edx { #define MSR_ARCH_PERFMON_FIXED_CTR2 0x30b #define X86_PMC_IDX_FIXED_BUS_CYCLES (X86_PMC_IDX_FIXED + 2) +#define set_perf_counter_pending() \ + set_tsk_thread_flag(current, TIF_PERF_COUNTERS); + #ifdef CONFIG_PERF_COUNTERS extern void init_hw_perf_counters(void); extern void perf_counters_lapic_init(int nmi); Index: linux-2.6/kernel/perf_counter.c =================================================================== --- linux-2.6.orig/kernel/perf_counter.c +++ linux-2.6/kernel/perf_counter.c @@ -1438,7 +1438,7 @@ static void perf_swcounter_interrupt(str if (nmi) { counter->wakeup_pending = 1; - set_tsk_thread_flag(current, TIF_PERF_COUNTERS); + set_perf_counter_pending(); } else wake_up(&counter->waitq); } -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/