Merge git://git.infradead.org/~dwmw2/mtd-2.6.35

[pandora-kernel.git] / arch / x86 / kernel / cpu / perf_event.c

diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c
index fd4db0d..5db5b7d 100644 (file)
--- a/arch/x86/kernel/cpu/perf_event.c
+++ b/arch/x86/kernel/cpu/perf_event.c
@@ -106,6 +106,7 @@ struct cpu_hw_events {
 
        int                     n_events;
        int                     n_added;
+       int                     n_txn;
        int                     assign[X86_PMC_IDX_MAX]; /* event to counter assignment */
        u64                     tags[X86_PMC_IDX_MAX];
        struct perf_event       *event_list[X86_PMC_IDX_MAX]; /* in enabled order */
@@ -983,6 +984,7 @@ static int x86_pmu_enable(struct perf_event *event)
 out:
        cpuc->n_events = n;
        cpuc->n_added += n - n0;
+       cpuc->n_txn += n - n0;
 
        return 0;
 }
@@ -1089,6 +1091,14 @@ static void x86_pmu_disable(struct perf_event *event)
        struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
        int i;
 
+       /*
+        * If we're called during a txn, we don't need to do anything.
+        * The events never got scheduled and ->cancel_txn will truncate
+        * the event_list.
+        */
+       if (cpuc->group_flag & PERF_EVENT_TXN_STARTED)
+               return;
+
        x86_pmu_stop(event);
 
        for (i = 0; i < cpuc->n_events; i++) {
@@ -1379,6 +1389,7 @@ static void x86_pmu_start_txn(const struct pmu *pmu)
        struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 
        cpuc->group_flag |= PERF_EVENT_TXN_STARTED;
+       cpuc->n_txn = 0;
 }
 
 /*
@@ -1391,6 +1402,11 @@ static void x86_pmu_cancel_txn(const struct pmu *pmu)
        struct cpu_hw_events *cpuc = &__get_cpu_var(cpu_hw_events);
 
        cpuc->group_flag &= ~PERF_EVENT_TXN_STARTED;
+       /*
+        * Truncate the collected events.
+        */
+       cpuc->n_added -= cpuc->n_txn;
+       cpuc->n_events -= cpuc->n_txn;
 }
 
 /*
@@ -1419,6 +1435,12 @@ static int x86_pmu_commit_txn(const struct pmu *pmu)
         */
        memcpy(cpuc->assign, assign, n*sizeof(int));
 
+       /*
+        * Clear out the txn count so that ->cancel_txn() which gets
+        * run after ->commit_txn() doesn't undo things.
+        */
+       cpuc->n_txn = 0;
+
        return 0;
 }
 
@@ -1717,7 +1739,11 @@ void perf_arch_fetch_caller_regs(struct pt_regs *regs, unsigned long ip, int ski
         */
        regs->bp = rewind_frame_pointer(skip + 1);
        regs->cs = __KERNEL_CS;
-       local_save_flags(regs->flags);
+       /*
+        * We abuse bit 3 to pass exact information, see perf_misc_flags
+        * and the comment with PERF_EFLAGS_EXACT.
+        */
+       regs->flags = 0;
 }
 
 unsigned long perf_instruction_pointer(struct pt_regs *regs)