summaryrefslogtreecommitdiffstats
path: root/kernel/perf_event.c
diff options
context:
space:
mode:
authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-09-07 17:34:50 +0200
committerIngo Molnar <mingo@elte.hu>2010-09-09 20:46:34 +0200
commit89a1e18731959e9953fae15ddc1a983eb15a4f19 (patch)
tree5a52e77acb23f47254c94e23eb6ed35a422fce1d /kernel/perf_event.c
parent8dc85d547285668e509f86c177bcd4ea055bcaaf (diff)
downloadop-kernel-dev-89a1e18731959e9953fae15ddc1a983eb15a4f19.zip
op-kernel-dev-89a1e18731959e9953fae15ddc1a983eb15a4f19.tar.gz
perf: Provide a separate task context for swevents
Since software events are always schedulable, mixing them up with hardware events (who are not) can lead to funny scheduling oddities. Giving them their own context solves this. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: paulus <paulus@samba.org> Cc: stephane eranian <eranian@googlemail.com> Cc: Robert Richter <robert.richter@amd.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Lin Ming <ming.m.lin@intel.com> Cc: Yanmin <yanmin_zhang@linux.intel.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/perf_event.c')
-rw-r--r--kernel/perf_event.c40
1 files changed, 29 insertions, 11 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 7223ea8..357ee8d 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -4709,6 +4709,8 @@ static int perf_swevent_init(struct perf_event *event)
}
static struct pmu perf_swevent = {
+ .task_ctx_nr = perf_sw_context,
+
.event_init = perf_swevent_init,
.add = perf_swevent_add,
.del = perf_swevent_del,
@@ -4800,6 +4802,8 @@ static int perf_tp_event_init(struct perf_event *event)
}
static struct pmu perf_tracepoint = {
+ .task_ctx_nr = perf_sw_context,
+
.event_init = perf_tp_event_init,
.add = perf_trace_add,
.del = perf_trace_del,
@@ -4988,6 +4992,8 @@ static int cpu_clock_event_init(struct perf_event *event)
}
static struct pmu perf_cpu_clock = {
+ .task_ctx_nr = perf_sw_context,
+
.event_init = cpu_clock_event_init,
.add = cpu_clock_event_add,
.del = cpu_clock_event_del,
@@ -5063,6 +5069,8 @@ static int task_clock_event_init(struct perf_event *event)
}
static struct pmu perf_task_clock = {
+ .task_ctx_nr = perf_sw_context,
+
.event_init = task_clock_event_init,
.add = task_clock_event_add,
.del = task_clock_event_del,
@@ -5490,6 +5498,7 @@ SYSCALL_DEFINE5(perf_event_open,
struct perf_event_context *ctx;
struct file *event_file = NULL;
struct file *group_file = NULL;
+ struct pmu *pmu;
int event_fd;
int fput_needed = 0;
int err;
@@ -5522,20 +5531,11 @@ SYSCALL_DEFINE5(perf_event_open,
goto err_fd;
}
- /*
- * Get the target context (task or percpu):
- */
- ctx = find_get_context(event->pmu, pid, cpu);
- if (IS_ERR(ctx)) {
- err = PTR_ERR(ctx);
- goto err_alloc;
- }
-
if (group_fd != -1) {
group_leader = perf_fget_light(group_fd, &fput_needed);
if (IS_ERR(group_leader)) {
err = PTR_ERR(group_leader);
- goto err_context;
+ goto err_alloc;
}
group_file = group_leader->filp;
if (flags & PERF_FLAG_FD_OUTPUT)
@@ -5545,6 +5545,23 @@ SYSCALL_DEFINE5(perf_event_open,
}
/*
+ * Special case software events and allow them to be part of
+ * any hardware group.
+ */
+ pmu = event->pmu;
+ if ((pmu->task_ctx_nr == perf_sw_context) && group_leader)
+ pmu = group_leader->pmu;
+
+ /*
+ * Get the target context (task or percpu):
+ */
+ ctx = find_get_context(pmu, pid, cpu);
+ if (IS_ERR(ctx)) {
+ err = PTR_ERR(ctx);
+ goto err_group_fd;
+ }
+
+ /*
* Look up the group leader (we will attach this event to it):
*/
if (group_leader) {
@@ -5605,8 +5622,9 @@ SYSCALL_DEFINE5(perf_event_open,
return event_fd;
err_context:
- fput_light(group_file, fput_needed);
put_ctx(ctx);
+err_group_fd:
+ fput_light(group_file, fput_needed);
err_alloc:
free_event(event);
err_fd:
OpenPOWER on IntegriCloud