[PATCH 2/2] perf/x86/intel/lbr: Fix the return type of get_lbr_cycles()

From: kan . liang
Date: Wed Nov 25 2020 - 16:39:09 EST


From: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>

The cycle count of a timed LBR is always 1 in perf record -D.

The cycle count is stored in the first 16 bits of the IA32_LBR_x_INFO
register, but the get_lbr_cycles() return Boolean type.

Use u16 to replace the Boolean type.

Fixes: 47125db27e47 ("perf/x86/intel/lbr: Support Architectural LBR")
Reported-by: Stephane Eranian <eranian@xxxxxxxxxx>
Signed-off-by: Kan Liang <kan.liang@xxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
arch/x86/events/intel/lbr.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c
index 1aadb253d296..21890dacfcfe 100644
--- a/arch/x86/events/intel/lbr.c
+++ b/arch/x86/events/intel/lbr.c
@@ -919,7 +919,7 @@ static __always_inline bool get_lbr_predicted(u64 info)
return !(info & LBR_INFO_MISPRED);
}

-static __always_inline bool get_lbr_cycles(u64 info)
+static __always_inline u16 get_lbr_cycles(u64 info)
{
if (static_cpu_has(X86_FEATURE_ARCH_LBR) &&
!(x86_pmu.lbr_timed_lbr && info & LBR_INFO_CYC_CNT_VALID))
--
2.17.1