Merge branch 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  perf: Fix reading in perf_event_read()
  watchdog: Don't change watchdog state on read of sysctl
  watchdog: Fix sysctl consistency
  watchdog: Fix broken nowatchdog logic
  perf: Fix Pentium4 raw event validation
  perf: Fix alloc_callchain_buffers()

2 files changed, 24 insertions, 29 deletions

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 126a302c481c..999835b6112b 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -1901,11 +1901,12 @@ static void __perf_event_read(void *info)
                 return;
 
         raw_spin_lock(&ctx->lock);
-        update_context_time(ctx);
+        if (ctx->is_active)
+                update_context_time(ctx);
         update_event_times(event);
+        if (event->state == PERF_EVENT_STATE_ACTIVE)
+                event->pmu->read(event);
         raw_spin_unlock(&ctx->lock);
-
-        event->pmu->read(event);
 }
 
 static inline u64 perf_event_count(struct perf_event *event)
@@ -1999,8 +2000,7 @@ static int alloc_callchain_buffers(void)
          * accessed from NMI. Use a temporary manual per cpu allocation
          * until that gets sorted out.
          */
-        size = sizeof(*entries) + sizeof(struct perf_callchain_entry *) *
-                num_possible_cpus();
+        size = offsetof(struct callchain_cpus_entries, cpu_entries[nr_cpu_ids]);
 
         entries = kzalloc(size, GFP_KERNEL);
         if (!entries)
diff --git a/kernel/watchdog.c b/kernel/watchdog.c
index d7ebdf4cea98..f37f974aa81b 100644
--- a/kernel/watchdog.c
+++ b/kernel/watchdog.c
@@ -27,7 +27,7 @@
 #include <asm/irq_regs.h>
 #include <linux/perf_event.h>
 
-int watchdog_enabled;
+int watchdog_enabled = 1;
 int __read_mostly softlockup_thresh = 60;
 
 static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts);
@@ -43,9 +43,6 @@ static DEFINE_PER_CPU(unsigned long, hrtimer_interrupts_saved);
 static DEFINE_PER_CPU(struct perf_event *, watchdog_ev);
 #endif
 
-static int no_watchdog;
-
-
 /* boot commands */
 /*
  * Should we panic when a soft-lockup or hard-lockup occurs:
@@ -58,7 +55,7 @@ static int __init hardlockup_panic_setup(char *str)
         if (!strncmp(str, "panic", 5))
                 hardlockup_panic = 1;
         else if (!strncmp(str, "0", 1))
-                no_watchdog = 1;
+                watchdog_enabled = 0;
         return 1;
 }
 __setup("nmi_watchdog=", hardlockup_panic_setup);
@@ -77,7 +74,7 @@ __setup("softlockup_panic=", softlockup_panic_setup);
 
 static int __init nowatchdog_setup(char *str)
 {
-        no_watchdog = 1;
+        watchdog_enabled = 0;
         return 1;
 }
 __setup("nowatchdog", nowatchdog_setup);
@@ -85,7 +82,7 @@ __setup("nowatchdog", nowatchdog_setup);
 /* deprecated */
 static int __init nosoftlockup_setup(char *str)
 {
-        no_watchdog = 1;
+        watchdog_enabled = 0;
         return 1;
 }
 __setup("nosoftlockup", nosoftlockup_setup);
@@ -432,9 +429,6 @@ static int watchdog_enable(int cpu)
                 wake_up_process(p);
         }
 
-        /* if any cpu succeeds, watchdog is considered enabled for the system */
-        watchdog_enabled = 1;
-
         return 0;
 }
 
@@ -462,12 +456,16 @@ static void watchdog_disable(int cpu)
 static void watchdog_enable_all_cpus(void)
 {
         int cpu;
-        int result = 0;
+
+        watchdog_enabled = 0;
 
         for_each_online_cpu(cpu)
-                result += watchdog_enable(cpu);
+                if (!watchdog_enable(cpu))
+                        /* if any cpu succeeds, watchdog is considered
+                           enabled for the system */
+                        watchdog_enabled = 1;
 
-        if (result)
+        if (!watchdog_enabled)
                 printk(KERN_ERR "watchdog: failed to be enabled on some cpus\n");
 
 }
@@ -476,9 +474,6 @@ static void watchdog_disable_all_cpus(void)
 {
         int cpu;
 
-        if (no_watchdog)
-                return;
-
         for_each_online_cpu(cpu)
                 watchdog_disable(cpu);
 
@@ -498,10 +493,12 @@ int proc_dowatchdog_enabled(struct ctl_table *table, int write,
 {
         proc_dointvec(table, write, buffer, length, ppos);
 
-        if (watchdog_enabled)
-                watchdog_enable_all_cpus();
-        else
-                watchdog_disable_all_cpus();
+        if (write) {
+                if (watchdog_enabled)
+                        watchdog_enable_all_cpus();
+                else
+                        watchdog_disable_all_cpus();
+        }
         return 0;
 }
 
@@ -530,7 +527,8 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu)
                 break;
         case CPU_ONLINE:
         case CPU_ONLINE_FROZEN:
-                err = watchdog_enable(hotcpu);
+                if (watchdog_enabled)
+                        err = watchdog_enable(hotcpu);
                 break;
 #ifdef CONFIG_HOTPLUG_CPU
         case CPU_UP_CANCELED:
@@ -555,9 +553,6 @@ void __init lockup_detector_init(void)
         void *cpu = (void *)(long)smp_processor_id();
         int err;
 
-        if (no_watchdog)
-                return;
-
         err = cpu_callback(&cpu_nfb, CPU_UP_PREPARE, cpu);
         WARN_ON(notifier_to_errno(err));