releases/4.19.51/perf-x86-intel-allow-pebs-multi-entry-in-watermark-m.patch

   1 From c35afa09949a596a06aba156d67afe720444cdd4 Mon Sep 17 00:00:00 2001
   2 From: Stephane Eranian <eranian@google.com>
   3 Date: Mon, 13 May 2019 17:34:00 -0700
   4 Subject: perf/x86/intel: Allow PEBS multi-entry in watermark mode
   5
   6 [ Upstream commit c7a286577d7592720c2f179aadfb325a1ff48c95 ]
   7
   8 This patch fixes a restriction/bug introduced by:
   9
  10    583feb08e7f7 ("perf/x86/intel: Fix handling of wakeup_events for multi-entry PEBS")
  11
  12 The original patch prevented using multi-entry PEBS when wakeup_events != 0.
  13 However given that wakeup_events is part of a union with wakeup_watermark, it
  14 means that in watermark mode, PEBS multi-entry is also disabled which is not the
  15 intent. This patch fixes this by checking is watermark mode is enabled.
  16
  17 Signed-off-by: Stephane Eranian <eranian@google.com>
  18 Cc: Linus Torvalds <torvalds@linux-foundation.org>
  19 Cc: Peter Zijlstra <peterz@infradead.org>
  20 Cc: Thomas Gleixner <tglx@linutronix.de>
  21 Cc: jolsa@redhat.com
  22 Cc: kan.liang@intel.com
  23 Cc: vincent.weaver@maine.edu
  24 Fixes: 583feb08e7f7 ("perf/x86/intel: Fix handling of wakeup_events for multi-entry PEBS")
  25 Link: http://lkml.kernel.org/r/20190514003400.224340-1-eranian@google.com
  26 Signed-off-by: Ingo Molnar <mingo@kernel.org>
  27 Signed-off-by: Sasha Levin <sashal@kernel.org>
  28 ---
  29  arch/x86/events/intel/core.c | 2 +-
  30  1 file changed, 1 insertion(+), 1 deletion(-)
  31
  32 diff --git a/arch/x86/events/intel/core.c b/arch/x86/events/intel/core.c
  33 index 09c53bcbd497..c8b0bf2b0d5e 100644
  34 --- a/arch/x86/events/intel/core.c
  35 +++ b/arch/x86/events/intel/core.c
  36 @@ -3072,7 +3072,7 @@ static int intel_pmu_hw_config(struct perf_event *event)
  37                 return ret;
  38
  39         if (event->attr.precise_ip) {
  40 -               if (!(event->attr.freq || event->attr.wakeup_events)) {
  41 +               if (!(event->attr.freq || (event->attr.wakeup_events && !event->attr.watermark))) {
  42                         event->hw.flags |= PERF_X86_EVENT_AUTO_RELOAD;
  43                         if (!(event->attr.sample_type &
  44                               ~intel_pmu_large_pebs_flags(event)))
  45 --
  46 2.20.1
  47