Merge branch 'tip/perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/urgent
diff --git a/arch/x86/kernel/cpu/perf_event_amd_ibs.c b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
index ab6343d..3b8a2d3 100644
--- a/arch/x86/kernel/cpu/perf_event_amd_ibs.c
+++ b/arch/x86/kernel/cpu/perf_event_amd_ibs.c
@@ -199,8 +199,7 @@
goto out;
}
- pr_err(FW_BUG "using offset %d for IBS interrupts\n", offset);
- pr_err(FW_BUG "workaround enabled for IBS LVT offset\n");
+ pr_info("IBS: LVT offset %d assigned\n", offset);
return 0;
out:
@@ -265,19 +264,23 @@
static __init int amd_ibs_init(void)
{
u32 caps;
- int ret;
+ int ret = -EINVAL;
caps = __get_ibs_caps();
if (!caps)
return -ENODEV; /* ibs not supported by the cpu */
- if (!ibs_eilvt_valid()) {
- ret = force_ibs_eilvt_setup();
- if (ret) {
- pr_err("Failed to setup IBS, %d\n", ret);
- return ret;
- }
- }
+ /*
+ * Force LVT offset assignment for family 10h: The offsets are
+ * not assigned by the BIOS for this family, so the OS is
+ * responsible for doing it. If the OS assignment fails, fall
+ * back to BIOS settings and try to setup this.
+ */
+ if (boot_cpu_data.x86 == 0x10)
+ force_ibs_eilvt_setup();
+
+ if (!ibs_eilvt_valid())
+ goto out;
get_online_cpus();
ibs_caps = caps;
@@ -287,7 +290,11 @@
smp_call_function(setup_APIC_ibs, NULL, 1);
put_online_cpus();
- return perf_event_ibs_init();
+ ret = perf_event_ibs_init();
+out:
+ if (ret)
+ pr_err("Failed to setup IBS, %d\n", ret);
+ return ret;
}
/* Since we need the pci subsystem to init ibs we can't do this earlier: */
diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c
index 2be5ebe..8d601b1 100644
--- a/arch/x86/kernel/cpu/perf_event_intel.c
+++ b/arch/x86/kernel/cpu/perf_event_intel.c
@@ -1545,6 +1545,13 @@
x86_pmu.pebs_constraints = NULL;
}
+static void intel_sandybridge_quirks(void)
+{
+ printk(KERN_WARNING "PEBS disabled due to CPU errata.\n");
+ x86_pmu.pebs = 0;
+ x86_pmu.pebs_constraints = NULL;
+}
+
__init int intel_pmu_init(void)
{
union cpuid10_edx edx;
@@ -1694,6 +1701,7 @@
break;
case 42: /* SandyBridge */
+ x86_pmu.quirks = intel_sandybridge_quirks;
case 45: /* SandyBridge, "Romely-EP" */
memcpy(hw_cache_event_ids, snb_hw_cache_event_ids,
sizeof(hw_cache_event_ids));
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 1e9ebe5..b1f8912 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -822,6 +822,7 @@
int mmap_locked;
struct user_struct *mmap_user;
struct ring_buffer *rb;
+ struct list_head rb_entry;
/* poll related */
wait_queue_head_t waitq;
diff --git a/kernel/events/core.c b/kernel/events/core.c
index b0c1186..600c162 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -185,6 +185,9 @@
static void update_context_time(struct perf_event_context *ctx);
static u64 perf_event_time(struct perf_event *event);
+static void ring_buffer_attach(struct perf_event *event,
+ struct ring_buffer *rb);
+
void __weak perf_event_print_debug(void) { }
extern __weak const char *perf_pmu_name(void)
@@ -3191,12 +3194,33 @@
struct ring_buffer *rb;
unsigned int events = POLL_HUP;
+ /*
+ * Race between perf_event_set_output() and perf_poll(): perf_poll()
+ * grabs the rb reference but perf_event_set_output() overrides it.
+ * Here is the timeline for two threads T1, T2:
+ * t0: T1, rb = rcu_dereference(event->rb)
+ * t1: T2, old_rb = event->rb
+ * t2: T2, event->rb = new rb
+ * t3: T2, ring_buffer_detach(old_rb)
+ * t4: T1, ring_buffer_attach(rb1)
+ * t5: T1, poll_wait(event->waitq)
+ *
+ * To avoid this problem, we grab mmap_mutex in perf_poll()
+ * thereby ensuring that the assignment of the new ring buffer
+ * and the detachment of the old buffer appear atomic to perf_poll()
+ */
+ mutex_lock(&event->mmap_mutex);
+
rcu_read_lock();
rb = rcu_dereference(event->rb);
- if (rb)
+ if (rb) {
+ ring_buffer_attach(event, rb);
events = atomic_xchg(&rb->poll, 0);
+ }
rcu_read_unlock();
+ mutex_unlock(&event->mmap_mutex);
+
poll_wait(file, &event->waitq, wait);
return events;
@@ -3497,6 +3521,49 @@
return ret;
}
+static void ring_buffer_attach(struct perf_event *event,
+ struct ring_buffer *rb)
+{
+ unsigned long flags;
+
+ if (!list_empty(&event->rb_entry))
+ return;
+
+ spin_lock_irqsave(&rb->event_lock, flags);
+ if (!list_empty(&event->rb_entry))
+ goto unlock;
+
+ list_add(&event->rb_entry, &rb->event_list);
+unlock:
+ spin_unlock_irqrestore(&rb->event_lock, flags);
+}
+
+static void ring_buffer_detach(struct perf_event *event,
+ struct ring_buffer *rb)
+{
+ unsigned long flags;
+
+ if (list_empty(&event->rb_entry))
+ return;
+
+ spin_lock_irqsave(&rb->event_lock, flags);
+ list_del_init(&event->rb_entry);
+ wake_up_all(&event->waitq);
+ spin_unlock_irqrestore(&rb->event_lock, flags);
+}
+
+static void ring_buffer_wakeup(struct perf_event *event)
+{
+ struct ring_buffer *rb;
+
+ rcu_read_lock();
+ rb = rcu_dereference(event->rb);
+ list_for_each_entry_rcu(event, &rb->event_list, rb_entry) {
+ wake_up_all(&event->waitq);
+ }
+ rcu_read_unlock();
+}
+
static void rb_free_rcu(struct rcu_head *rcu_head)
{
struct ring_buffer *rb;
@@ -3522,9 +3589,19 @@
static void ring_buffer_put(struct ring_buffer *rb)
{
+ struct perf_event *event, *n;
+ unsigned long flags;
+
if (!atomic_dec_and_test(&rb->refcount))
return;
+ spin_lock_irqsave(&rb->event_lock, flags);
+ list_for_each_entry_safe(event, n, &rb->event_list, rb_entry) {
+ list_del_init(&event->rb_entry);
+ wake_up_all(&event->waitq);
+ }
+ spin_unlock_irqrestore(&rb->event_lock, flags);
+
call_rcu(&rb->rcu_head, rb_free_rcu);
}
@@ -3547,6 +3624,7 @@
atomic_long_sub((size >> PAGE_SHIFT) + 1, &user->locked_vm);
vma->vm_mm->pinned_vm -= event->mmap_locked;
rcu_assign_pointer(event->rb, NULL);
+ ring_buffer_detach(event, rb);
mutex_unlock(&event->mmap_mutex);
ring_buffer_put(rb);
@@ -3701,7 +3779,7 @@
void perf_event_wakeup(struct perf_event *event)
{
- wake_up_all(&event->waitq);
+ ring_buffer_wakeup(event);
if (event->pending_kill) {
kill_fasync(&event->fasync, SIGIO, event->pending_kill);
@@ -5823,6 +5901,8 @@
INIT_LIST_HEAD(&event->group_entry);
INIT_LIST_HEAD(&event->event_entry);
INIT_LIST_HEAD(&event->sibling_list);
+ INIT_LIST_HEAD(&event->rb_entry);
+
init_waitqueue_head(&event->waitq);
init_irq_work(&event->pending, perf_pending_event);
@@ -6029,6 +6109,8 @@
old_rb = event->rb;
rcu_assign_pointer(event->rb, rb);
+ if (old_rb)
+ ring_buffer_detach(event, old_rb);
ret = 0;
unlock:
mutex_unlock(&event->mmap_mutex);
diff --git a/kernel/events/internal.h b/kernel/events/internal.h
index 09097dd..64568a6 100644
--- a/kernel/events/internal.h
+++ b/kernel/events/internal.h
@@ -22,6 +22,9 @@
local_t lost; /* nr records lost */
long watermark; /* wakeup watermark */
+ /* poll crap */
+ spinlock_t event_lock;
+ struct list_head event_list;
struct perf_event_mmap_page *user_page;
void *data_pages[0];
diff --git a/kernel/events/ring_buffer.c b/kernel/events/ring_buffer.c
index a2a2920..7f3011c 100644
--- a/kernel/events/ring_buffer.c
+++ b/kernel/events/ring_buffer.c
@@ -209,6 +209,9 @@
rb->writable = 1;
atomic_set(&rb->refcount, 1);
+
+ INIT_LIST_HEAD(&rb->event_list);
+ spin_lock_init(&rb->event_lock);
}
#ifndef CONFIG_PERF_USE_VMALLOC
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index e426264..d7915d4 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -34,6 +34,16 @@
return size;
}
+static void hists__init(struct hists *hists)
+{
+ memset(hists, 0, sizeof(*hists));
+ hists->entries_in_array[0] = hists->entries_in_array[1] = RB_ROOT;
+ hists->entries_in = &hists->entries_in_array[0];
+ hists->entries_collapsed = RB_ROOT;
+ hists->entries = RB_ROOT;
+ pthread_mutex_init(&hists->lock, NULL);
+}
+
void perf_evsel__init(struct perf_evsel *evsel,
struct perf_event_attr *attr, int idx)
{
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index a36a3fa..abef270 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -1211,13 +1211,3 @@
return ret;
}
-
-void hists__init(struct hists *hists)
-{
- memset(hists, 0, sizeof(*hists));
- hists->entries_in_array[0] = hists->entries_in_array[1] = RB_ROOT;
- hists->entries_in = &hists->entries_in_array[0];
- hists->entries_collapsed = RB_ROOT;
- hists->entries = RB_ROOT;
- pthread_mutex_init(&hists->lock, NULL);
-}
diff --git a/tools/perf/util/hist.h b/tools/perf/util/hist.h
index c86c1d2..89289c8 100644
--- a/tools/perf/util/hist.h
+++ b/tools/perf/util/hist.h
@@ -63,8 +63,6 @@
struct callchain_cursor callchain_cursor;
};
-void hists__init(struct hists *hists);
-
struct hist_entry *__hists__add_entry(struct hists *self,
struct addr_location *al,
struct symbol *parent, u64 period);
diff --git a/tools/perf/util/session.c b/tools/perf/util/session.c
index 85c1e6b7..0f4555c 100644
--- a/tools/perf/util/session.c
+++ b/tools/perf/util/session.c
@@ -1333,6 +1333,10 @@
}
map = cpu_map__new(cpu_list);
+ if (map == NULL) {
+ pr_err("Invalid cpu_list\n");
+ return -1;
+ }
for (i = 0; i < map->nr; i++) {
int cpu = map->map[i];