linux-kernel - [PATCH v2 01/15] perf/x86/lbr: Simplify the exposure check for the LBR

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Message-Id: <20221125040604.5051-2-weijiang.yang@intel.com>
Date:   Thu, 24 Nov 2022 23:05:50 -0500
From:   Yang Weijiang <weijiang.yang@...el.com>
To:     seanjc@...gle.com, pbonzini@...hat.com, jmattson@...gle.com,
        kvm@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     like.xu.linux@...il.com, kan.liang@...ux.intel.com,
        wei.w.wang@...el.com, weijiang.yang@...el.com,
        Like Xu <like.xu@...ux.intel.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Andi Kleen <ak@...ux.intel.com>
Subject: [PATCH v2 01/15] perf/x86/lbr: Simplify the exposure check for the LBR_INFO registers

From: Like Xu <like.xu@...ux.intel.com>

The x86_pmu.lbr_info is 0 unless explicitly initialized, so there's
no point checking x86_pmu.intel_cap.lbr_format.

Cc: Peter Zijlstra <peterz@...radead.org>
Reviewed-by: Kan Liang <kan.liang@...ux.intel.com>
Reviewed-by: Andi Kleen <ak@...ux.intel.com>
Signed-off-by: Like Xu <like.xu@...ux.intel.com>
Signed-off-by: Yang Weijiang <weijiang.yang@...el.com>
---
 arch/x86/events/intel/lbr.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/arch/x86/events/intel/lbr.c b/arch/x86/events/intel/lbr.c
index 4dbde69c423b..e7caabfa1377 100644
--- a/arch/x86/events/intel/lbr.c
+++ b/arch/x86/events/intel/lbr.c
@@ -1606,12 +1606,10 @@ void __init intel_pmu_arch_lbr_init(void)
  */
 void x86_perf_get_lbr(struct x86_pmu_lbr *lbr)
 {
-	int lbr_fmt = x86_pmu.intel_cap.lbr_format;
-
 	lbr->nr = x86_pmu.lbr_nr;
 	lbr->from = x86_pmu.lbr_from;
 	lbr->to = x86_pmu.lbr_to;
-	lbr->info = (lbr_fmt == LBR_FORMAT_INFO) ? x86_pmu.lbr_info : 0;
+	lbr->info = x86_pmu.lbr_info;
 }
 EXPORT_SYMBOL_GPL(x86_perf_get_lbr);
 
-- 
2.27.0