linux-kernel - [RFC PATCH 09/15] alpha/perf: Remove driver-specific throttle support

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Message-Id: <20250506164740.1317237-10-kan.liang@linux.intel.com>
Date: Tue,  6 May 2025 09:47:34 -0700
From: kan.liang@...ux.intel.com
To: peterz@...radead.org,
	mingo@...hat.com,
	namhyung@...nel.org,
	irogers@...gle.com,
	mark.rutland@....com,
	linux-kernel@...r.kernel.org,
	linux-perf-users@...r.kernel.org
Cc: eranian@...gle.com,
	ctshao@...gle.com,
	tmricht@...ux.ibm.com,
	Kan Liang <kan.liang@...ux.intel.com>,
	linux-alpha@...r.kernel.org
Subject: [RFC PATCH 09/15] alpha/perf: Remove driver-specific throttle support

From: Kan Liang <kan.liang@...ux.intel.com>

The throttle support has been added in the generic code. Remove
the driver-specific throttle support.

Besides the throttle, perf_event_overflow may return true because of
event_limit. It already does an inatomic event disable. The pmu->stop
is not required either.

Signed-off-by: Kan Liang <kan.liang@...ux.intel.com>
Cc: linux-alpha@...r.kernel.org
---
 arch/alpha/kernel/perf_event.c | 11 +++--------
 1 file changed, 3 insertions(+), 8 deletions(-)

diff --git a/arch/alpha/kernel/perf_event.c b/arch/alpha/kernel/perf_event.c
index 1f0eb4f25c0f..a3eaab094ece 100644
--- a/arch/alpha/kernel/perf_event.c
+++ b/arch/alpha/kernel/perf_event.c
@@ -852,14 +852,9 @@ static void alpha_perf_event_irq_handler(unsigned long la_ptr,
 	alpha_perf_event_update(event, hwc, idx, alpha_pmu->pmc_max_period[idx]+1);
 	perf_sample_data_init(&data, 0, hwc->last_period);
 
-	if (alpha_perf_event_set_period(event, hwc, idx)) {
-		if (perf_event_overflow(event, &data, regs)) {
-			/* Interrupts coming too quickly; "throttle" the
-			 * counter, i.e., disable it for a little while.
-			 */
-			alpha_pmu_stop(event, 0);
-		}
-	}
+	if (alpha_perf_event_set_period(event, hwc, idx))
+		perf_event_overflow(event, &data, regs);
+
 	wrperfmon(PERFMON_CMD_ENABLE, cpuc->idx_mask);
 
 	return;
-- 
2.38.1