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authorDavid S. Miller <davem@davemloft.net>2017-08-22 03:06:42 +0300
committerDavid S. Miller <davem@davemloft.net>2017-08-22 03:06:42 +0300
commite2a7c34fb2856fd5306e307e170e3dde358d0dce (patch)
treeafeb300b04186b1a1f649b2cd8a401a75878297c /kernel/events
parent7d3f0cd43feea1636dd7746f22fe8249b34d1b79 (diff)
parent6470812e22261d2342ef1597be62e63a0423d691 (diff)
downloadlinux-e2a7c34fb2856fd5306e307e170e3dde358d0dce.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Diffstat (limited to 'kernel/events')
-rw-r--r--kernel/events/core.c47
1 files changed, 39 insertions, 8 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index a7a6c1d19a49..8c01572709ac 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2217,6 +2217,33 @@ static int group_can_go_on(struct perf_event *event,
return can_add_hw;
}
+/*
+ * Complement to update_event_times(). This computes the tstamp_* values to
+ * continue 'enabled' state from @now, and effectively discards the time
+ * between the prior tstamp_stopped and now (as we were in the OFF state, or
+ * just switched (context) time base).
+ *
+ * This further assumes '@event->state == INACTIVE' (we just came from OFF) and
+ * cannot have been scheduled in yet. And going into INACTIVE state means
+ * '@event->tstamp_stopped = @now'.
+ *
+ * Thus given the rules of update_event_times():
+ *
+ * total_time_enabled = tstamp_stopped - tstamp_enabled
+ * total_time_running = tstamp_stopped - tstamp_running
+ *
+ * We can insert 'tstamp_stopped == now' and reverse them to compute new
+ * tstamp_* values.
+ */
+static void __perf_event_enable_time(struct perf_event *event, u64 now)
+{
+ WARN_ON_ONCE(event->state != PERF_EVENT_STATE_INACTIVE);
+
+ event->tstamp_stopped = now;
+ event->tstamp_enabled = now - event->total_time_enabled;
+ event->tstamp_running = now - event->total_time_running;
+}
+
static void add_event_to_ctx(struct perf_event *event,
struct perf_event_context *ctx)
{
@@ -2224,9 +2251,12 @@ static void add_event_to_ctx(struct perf_event *event,
list_add_event(event, ctx);
perf_group_attach(event);
- event->tstamp_enabled = tstamp;
- event->tstamp_running = tstamp;
- event->tstamp_stopped = tstamp;
+ /*
+ * We can be called with event->state == STATE_OFF when we create with
+ * .disabled = 1. In that case the IOC_ENABLE will call this function.
+ */
+ if (event->state == PERF_EVENT_STATE_INACTIVE)
+ __perf_event_enable_time(event, tstamp);
}
static void ctx_sched_out(struct perf_event_context *ctx,
@@ -2471,10 +2501,11 @@ static void __perf_event_mark_enabled(struct perf_event *event)
u64 tstamp = perf_event_time(event);
event->state = PERF_EVENT_STATE_INACTIVE;
- event->tstamp_enabled = tstamp - event->total_time_enabled;
+ __perf_event_enable_time(event, tstamp);
list_for_each_entry(sub, &event->sibling_list, group_entry) {
+ /* XXX should not be > INACTIVE if event isn't */
if (sub->state >= PERF_EVENT_STATE_INACTIVE)
- sub->tstamp_enabled = tstamp - sub->total_time_enabled;
+ __perf_event_enable_time(sub, tstamp);
}
}
@@ -5090,7 +5121,7 @@ static void perf_mmap_open(struct vm_area_struct *vma)
atomic_inc(&event->rb->aux_mmap_count);
if (event->pmu->event_mapped)
- event->pmu->event_mapped(event);
+ event->pmu->event_mapped(event, vma->vm_mm);
}
static void perf_pmu_output_stop(struct perf_event *event);
@@ -5113,7 +5144,7 @@ static void perf_mmap_close(struct vm_area_struct *vma)
unsigned long size = perf_data_size(rb);
if (event->pmu->event_unmapped)
- event->pmu->event_unmapped(event);
+ event->pmu->event_unmapped(event, vma->vm_mm);
/*
* rb->aux_mmap_count will always drop before rb->mmap_count and
@@ -5411,7 +5442,7 @@ aux_unlock:
vma->vm_ops = &perf_mmap_vmops;
if (event->pmu->event_mapped)
- event->pmu->event_mapped(event);
+ event->pmu->event_mapped(event, vma->vm_mm);
return ret;
}