ci/diffs: replace perf reverts with a proper fix

Link: https://lore.kernel.org/bpf/d3c6b899-7281-4f97-a449-96f506181bab@linux.intel.com/
Signed-off-by: Ihor Solodrai <isolodrai@meta.com>

Author: theihor

ci/diffs/20250601-0003-Revert-perf-Only-dump-the-throttle-log-for-the-leade.patch

@@ -1,7 +1,7 @@
 From 4b65d5ae971430287855a89635a184c489bd02a5 Mon Sep 17 00:00:00 2001
 From: Saket Kumar Bhaskar <skb99@linux.ibm.com>
 Date: Mon, 12 May 2025 14:41:07 +0530
-Subject: [PATCH 1/4] selftests/bpf: Fix bpf selftest build error
+Subject: [PATCH 1/3] selftests/bpf: Fix bpf selftest build error
 
 On linux-next, build for bpf selftest displays an error due to
 mismatch in the expected function signature of bpf_testmod_test_read

ci/diffs/20250601-0004-Revert-perf-Fix-the-throttle-logic-for-a-group.patch

@@ -1,7 +1,7 @@
 From baa39c169dd526cb0186187fc44ec462266efcc6 Mon Sep 17 00:00:00 2001
 From: Yonghong Song <yonghong.song@linux.dev>
 Date: Thu, 29 May 2025 13:11:51 -0700
-Subject: [PATCH 2/4] selftests/bpf: Fix selftest
+Subject: [PATCH 2/3] selftests/bpf: Fix selftest
  btf_tag/btf_type_tag_percpu_vmlinux_helper failure
 
 Ihor Solodrai reported selftest 'btf_tag/btf_type_tag_percpu_vmlinux_helper'

…s-bpf-Fix-bpf-selftest-build-error.patch …s-bpf-Fix-bpf-selftest-build-error.patchci/diffs/20250601-0001-selftests-bpf-Fix-bpf-selftest-build-error.patch renamed to ci/diffs/20250602-0001-selftests-bpf-Fix-bpf-selftest-build-error.patch ci/diffs/20250601-0001-selftests-bpf-Fix-bpf-selftest-build-error.patch renamed to ci/diffs/20250602-0001-selftests-bpf-Fix-bpf-selftest-build-error.patch

@@ -0,0 +1,98 @@
+From df3bed9ea57603e62696a2f8aee9609d3500b7d1 Mon Sep 17 00:00:00 2001
+From: Kan Liang <kan.liang@linux.intel.com>
+Date: Wed, 28 May 2025 10:58:32 -0700
+Subject: [PATCH 3/3] perf: Fix the throttle error of some clock events
+
+The Arm CI reports RCU stall, which can be reproduced by the below perf
+command.
+  perf record -a -e cpu-clock -- sleep 2
+
+The cpu-clock and task_clock are two special SW events, which rely on
+the hrtimer. Instead of invoking the stop(), the HRTIMER_NORESTART is
+returned to stop the timer. Because the hrtimer interrupt handler cannot
+cancel itself, which causes infinite loop.
+
+There may be two ways to fix it.
+- Add a check of MAX_INTERRUPTS in the event_stop. Return immediately if
+the stop is invoked by the throttle.
+- Introduce a PMU flag to track the case. Avoid the event_stop in
+perf_event_throttle() if the flag is detected.
+
+The latter looks more generic. It may be used if there are more other
+cases that want to avoid the stop later. The latter is implemented.
+
+Reported-by: Leo Yan <leo.yan@arm.com>
+Reported-by: Aishwarya TCV <aishwarya.tcv@arm.com>
+Closes: https://lore.kernel.org/lkml/20250527161656.GJ2566836@e132581.arm.com/
+Tested-by: Leo Yan <leo.yan@arm.com>
+Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
+Link: https://lore.kernel.org/r/20250528175832.2999139-1-kan.liang@linux.intel.com
+Signed-off-by: Alexei Starovoitov <ast@kernel.org>
+---
+ include/linux/perf_event.h |  1 +
+ kernel/events/core.c       | 23 ++++++++++++++++++++---
+ 2 files changed, 21 insertions(+), 3 deletions(-)
+
+diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
+index 52dc7cfab0e0..97a747a97a50 100644
+--- a/include/linux/perf_event.h
++++ b/include/linux/perf_event.h
+@@ -305,6 +305,7 @@ struct perf_event_pmu_context;
+ #define PERF_PMU_CAP_EXTENDED_HW_TYPE	0x0100
+ #define PERF_PMU_CAP_AUX_PAUSE		0x0200
+ #define PERF_PMU_CAP_AUX_PREFER_LARGE	0x0400
++#define PERF_PMU_CAP_NO_THROTTLE_STOP	0x0800
+ 
+ /**
+  * pmu::scope
+diff --git a/kernel/events/core.c b/kernel/events/core.c
+index f34c99f8ce8f..abd19bb571e3 100644
+--- a/kernel/events/core.c
++++ b/kernel/events/core.c
+@@ -2656,7 +2656,22 @@ static void perf_event_unthrottle(struct perf_event *event, bool start)
+ 
+ static void perf_event_throttle(struct perf_event *event)
+ {
+-	event->pmu->stop(event, 0);
++	/*
++	 * Some PMUs, e.g., cpu-clock and task_clock, may rely on
++	 * a special mechanism (hrtimer) to manipulate counters.
++	 * The regular stop doesn't work, since the hrtimer interrupt
++	 * handler cannot cancel itself.
++	 *
++	 * The stop should be avoided for such cases. Let the
++	 * driver-specific code handle it.
++	 *
++	 * The counters will eventually be disabled in the driver-specific
++	 * code. In unthrottle, they still need to be re-enabled.
++	 * There is no handling for PERF_PMU_CAP_NO_THROTTLE_STOP in
++	 * the perf_event_unthrottle().
++	 */
++	if (!(event->pmu->capabilities & PERF_PMU_CAP_NO_THROTTLE_STOP))
++		event->pmu->stop(event, 0);
+ 	event->hw.interrupts = MAX_INTERRUPTS;
+ 	if (event == event->group_leader)
+ 		perf_log_throttle(event, 0);
+@@ -11848,7 +11863,8 @@ static int cpu_clock_event_init(struct perf_event *event)
+ static struct pmu perf_cpu_clock = {
+ 	.task_ctx_nr	= perf_sw_context,
+ 
+-	.capabilities	= PERF_PMU_CAP_NO_NMI,
++	.capabilities	= PERF_PMU_CAP_NO_NMI |
++			  PERF_PMU_CAP_NO_THROTTLE_STOP,
+ 	.dev		= PMU_NULL_DEV,
+ 
+ 	.event_init	= cpu_clock_event_init,
+@@ -11930,7 +11946,8 @@ static int task_clock_event_init(struct perf_event *event)
+ static struct pmu perf_task_clock = {
+ 	.task_ctx_nr	= perf_sw_context,
+ 
+-	.capabilities	= PERF_PMU_CAP_NO_NMI,
++	.capabilities	= PERF_PMU_CAP_NO_NMI |
++			  PERF_PMU_CAP_NO_THROTTLE_STOP,
+ 	.dev		= PMU_NULL_DEV,
+ 
+ 	.event_init	= task_clock_event_init,
+-- 
+2.49.0
+