From 54fa190d0a548f7e403aa5d73e830b8aeecbf27b Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 8 Dec 2016 16:14:17 -0800 Subject: [PATCH] perf/x86: Fix exclusion of BTS and LBR for Goldmont commit b0c1ef52959582144bbea9a2b37db7f4c9e399f7 upstream. An earlier patch allowed enabling PT and LBR at the same time on Goldmont. However it also allowed enabling BTS and LBR at the same time, which is still not supported. Fix this by bypassing the check only for PT. Signed-off-by: Andi Kleen Signed-off-by: Peter Zijlstra (Intel) Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: alexander.shishkin@intel.com Cc: kan.liang@intel.com Fixes: ccbebba4c6bf ("perf/x86/intel/pt: Bypass PT vs. LBR exclusivity if the core supports it") Link: http://lkml.kernel.org/r/20161209001417.4713-1-andi@firstfloor.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- arch/x86/events/core.c | 8 ++++++-- arch/x86/events/perf_event.h | 2 +- 2 files changed, 7 insertions(+), 3 deletions(-) diff --git a/arch/x86/events/core.c b/arch/x86/events/core.c index 6e395c9..7fe88bb 100644 --- a/arch/x86/events/core.c +++ b/arch/x86/events/core.c @@ -365,7 +365,11 @@ int x86_add_exclusive(unsigned int what) { int i; - if (x86_pmu.lbr_pt_coexist) + /* + * When lbr_pt_coexist we allow PT to coexist with either LBR or BTS. + * LBR and BTS are still mutually exclusive. + */ + if (x86_pmu.lbr_pt_coexist && what == x86_lbr_exclusive_pt) return 0; if (!atomic_inc_not_zero(&x86_pmu.lbr_exclusive[what])) { @@ -388,7 +392,7 @@ fail_unlock: void x86_del_exclusive(unsigned int what) { - if (x86_pmu.lbr_pt_coexist) + if (x86_pmu.lbr_pt_coexist && what == x86_lbr_exclusive_pt) return; atomic_dec(&x86_pmu.lbr_exclusive[what]); diff --git a/arch/x86/events/perf_event.h b/arch/x86/events/perf_event.h index a77ee02..bcbb1d2 100644 --- a/arch/x86/events/perf_event.h +++ b/arch/x86/events/perf_event.h @@ -604,7 +604,7 @@ struct x86_pmu { u64 lbr_sel_mask; /* LBR_SELECT valid bits */ const int *lbr_sel_map; /* lbr_select mappings */ bool lbr_double_abort; /* duplicated lbr aborts */ - bool lbr_pt_coexist; /* LBR may coexist with PT */ + bool lbr_pt_coexist; /* (LBR|BTS) may coexist with PT */ /* * Intel PT/LBR/BTS are exclusive -- 2.7.4