[PATCH] perf/x86: Add cond_resched() when allocate/release DS buffers

[Namhyung Kim]

On large systems, it's possible to trigger sched latency warning during
the DS buffer allocation or release.  Add cond_resched() to avoid it.

Reported-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
 arch/x86/events/intel/ds.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index c0b7ac1c7594ea92..c8e90c5a8d3390ab 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -754,6 +754,7 @@ void release_ds_buffers(void)
 		if (x86_pmu.ds_pebs)
 			release_pebs_buffer(cpu);
 		release_bts_buffer(cpu);
+		cond_resched();
 	}
 }
 
@@ -791,6 +792,8 @@ void reserve_ds_buffers(void)
 
 		if (bts_err && pebs_err)
 			break;
+
+		cond_resched();
 	}
 
 	if (bts_err) {
-- 
2.51.1.838.g19442a804e-goog