linux-kernel - [Patch v6 03/22] perf/x86/intel: Convert x86_perf

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Message-Id: <20260209072047.2180332-4-dapeng1.mi@linux.intel.com>
Date: Mon,  9 Feb 2026 15:20:28 +0800
From: Dapeng Mi <dapeng1.mi@...ux.intel.com>
To: Peter Zijlstra <peterz@...radead.org>,
	Ingo Molnar <mingo@...hat.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>,
	Namhyung Kim <namhyung@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Dave Hansen <dave.hansen@...ux.intel.com>,
	Ian Rogers <irogers@...gle.com>,
	Adrian Hunter <adrian.hunter@...el.com>,
	Jiri Olsa <jolsa@...nel.org>,
	Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
	Andi Kleen <ak@...ux.intel.com>,
	Eranian Stephane <eranian@...gle.com>
Cc: Mark Rutland <mark.rutland@....com>,
	broonie@...nel.org,
	Ravi Bangoria <ravi.bangoria@....com>,
	linux-kernel@...r.kernel.org,
	linux-perf-users@...r.kernel.org,
	Zide Chen <zide.chen@...el.com>,
	Falcon Thomas <thomas.falcon@...el.com>,
	Dapeng Mi <dapeng1.mi@...el.com>,
	Xudong Hao <xudong.hao@...el.com>,
	Dapeng Mi <dapeng1.mi@...ux.intel.com>
Subject: [Patch v6 03/22] perf/x86/intel: Convert x86_perf_regs to per-cpu variables

Currently, the intel_pmu_drain_pebs_icl() and intel_pmu_drain_arch_pebs()
helpers define many temporary variables. Upcoming patches will add new
fields like *ymm_regs and *zmm_regs to the x86_perf_regs structure to
support sampling for these SIMD registers. This would increase the stack
size consumed by these helpers, potentially triggering the warning:
"the frame size of 1048 bytes is larger than 1024 bytes
 [-Wframe-larger-than=]".

To eliminate this warning, convert x86_perf_regs to per-cpu variables.

No functional changes are intended.

Signed-off-by: Dapeng Mi <dapeng1.mi@...ux.intel.com>
---

V6: new patch.

 arch/x86/events/intel/ds.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/arch/x86/events/intel/ds.c b/arch/x86/events/intel/ds.c
index 57805c6ba0c3..87bf8672f5a8 100644
--- a/arch/x86/events/intel/ds.c
+++ b/arch/x86/events/intel/ds.c
@@ -3174,14 +3174,16 @@ __intel_pmu_handle_last_pebs_record(struct pt_regs *iregs,
 
 }
 
+DEFINE_PER_CPU(struct x86_perf_regs, pebs_perf_regs);
+
 static void intel_pmu_drain_pebs_icl(struct pt_regs *iregs, struct perf_sample_data *data)
 {
 	short counts[INTEL_PMC_IDX_FIXED + MAX_FIXED_PEBS_EVENTS] = {};
 	void *last[INTEL_PMC_IDX_FIXED + MAX_FIXED_PEBS_EVENTS];
 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	struct debug_store *ds = cpuc->ds;
-	struct x86_perf_regs perf_regs;
-	struct pt_regs *regs = &perf_regs.regs;
+	struct x86_perf_regs *perf_regs = this_cpu_ptr(&pebs_perf_regs);
+	struct pt_regs *regs = &perf_regs->regs;
 	struct pebs_basic *basic;
 	void *base, *at, *top;
 	u64 mask;
@@ -3231,8 +3233,8 @@ static void intel_pmu_drain_arch_pebs(struct pt_regs *iregs,
 	void *last[INTEL_PMC_IDX_FIXED + MAX_FIXED_PEBS_EVENTS];
 	struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
 	union arch_pebs_index index;
-	struct x86_perf_regs perf_regs;
-	struct pt_regs *regs = &perf_regs.regs;
+	struct x86_perf_regs *perf_regs = this_cpu_ptr(&pebs_perf_regs);
+	struct pt_regs *regs = &perf_regs->regs;
 	void *base, *at, *top;
 	u64 mask;
 
-- 
2.34.1