4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Andi Kleen <[email protected]> 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 <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Fixes: ccbebba4c6bf ("perf/x86/intel/pt: Bypass PT vs. LBR exclusivity if the core supports it") Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/events/core.c | 8 ++++++-- arch/x86/events/perf_event.h | 2 +- 2 files changed, 7 insertions(+), 3 deletions(-) --- 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]); --- 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
