From: Stephane Eranian <eranian@google.com>
To: linux-kernel@vger.kernel.org
Cc: peterz@infradead.org, kim.phillips@amd.com, acme@redhat.com,
jolsa@redhat.com, songliubraving@fb.com, mpe@ellerman.id.au,
maddy@linux.ibm.com
Subject: [PATCH v4 08/14] ACPI: add perf low power callback
Date: Fri, 10 Dec 2021 13:02:23 -0800 [thread overview]
Message-ID: <20211210210229.2991238-9-eranian@google.com> (raw)
In-Reply-To: <20211210210229.2991238-1-eranian@google.com>
This patch add an optional callback needed by some PMU features, e.g., AMD
BRS, to give a chance to the perf_events code to change its state before
going to low power and after coming back.
The callback is void when the PERF_NEEDS_LOPWR_CB flag is not set.
This flag must be set in arch specific perf_event.h header whenever needed.
When not set, there is no impact of the ACPI code.
Signed-off-by: Stephane Eranian <eranian@google.com>
---
drivers/acpi/acpi_pad.c | 6 ++++++
drivers/acpi/processor_idle.c | 5 +++++
include/linux/perf_event.h | 6 ++++++
3 files changed, 17 insertions(+)
diff --git a/drivers/acpi/acpi_pad.c b/drivers/acpi/acpi_pad.c
index f45979aa2d64..a306a07a60b5 100644
--- a/drivers/acpi/acpi_pad.c
+++ b/drivers/acpi/acpi_pad.c
@@ -164,6 +164,9 @@ static int power_saving_thread(void *data)
tsc_marked_unstable = 1;
}
local_irq_disable();
+
+ perf_lopwr_cb(true);
+
tick_broadcast_enable();
tick_broadcast_enter();
stop_critical_timings();
@@ -172,6 +175,9 @@ static int power_saving_thread(void *data)
start_critical_timings();
tick_broadcast_exit();
+
+ perf_lopwr_cb(false);
+
local_irq_enable();
if (time_before(expire_time, jiffies)) {
diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 76ef1bcc8848..7a3a613ae5ed 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -20,6 +20,7 @@
#include <linux/tick.h>
#include <linux/cpuidle.h>
#include <linux/cpu.h>
+#include <linux/perf_event.h>
#include <acpi/processor.h>
/*
@@ -546,6 +547,8 @@ static void wait_for_freeze(void)
*/
static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
{
+ perf_lopwr_cb(true);
+
if (cx->entry_method == ACPI_CSTATE_FFH) {
/* Call into architectural FFH based C-state */
acpi_processor_ffh_cstate_enter(cx);
@@ -556,6 +559,8 @@ static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
inb(cx->address);
wait_for_freeze();
}
+
+ perf_lopwr_cb(false);
}
/**
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index bbe02c80244b..f9760873e145 100644
--- a/include/linux/perf_event.h
+++ b/include/linux/perf_event.h
@@ -1674,4 +1674,10 @@ typedef int (perf_snapshot_branch_stack_t)(struct perf_branch_entry *entries,
unsigned int cnt);
DECLARE_STATIC_CALL(perf_snapshot_branch_stack, perf_snapshot_branch_stack_t);
+#ifndef PERF_NEEDS_LOPWR_CB
+static inline void perf_lopwr_cb(bool mode)
+{
+}
+#endif
+
#endif /* _LINUX_PERF_EVENT_H */
--
2.34.1.173.g76aa8bc2d0-goog
next prev parent reply other threads:[~2021-12-10 21:03 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-10 21:02 [PATCH v4 00/14] perf/x86/amd: Add AMD Fam19h Branch Sampling support Stephane Eranian
2021-12-10 21:02 ` [PATCH v4 01/14] perf/core: add perf_clear_branch_entry_bitfields() helper Stephane Eranian
2021-12-10 21:02 ` [PATCH v4 02/14] x86/cpufeatures: add AMD Fam19h Branch Sampling feature Stephane Eranian
2021-12-10 21:21 ` Borislav Petkov
2021-12-10 21:25 ` Stephane Eranian
2021-12-10 21:02 ` [PATCH v4 03/14] perf/x86/amd: add AMD Fam19h Branch Sampling support Stephane Eranian
2021-12-29 9:54 ` Like Xu
2022-01-03 23:24 ` Stephane Eranian
2021-12-10 21:02 ` [PATCH v4 04/14] perf/x86/amd: add branch-brs helper event for Fam19h BRS Stephane Eranian
2021-12-10 21:02 ` [PATCH v4 05/14] perf/x86/amd: enable branch sampling priv level filtering Stephane Eranian
2021-12-10 21:02 ` [PATCH v4 06/14] perf/x86/amd: add AMD branch sampling period adjustment Stephane Eranian
2021-12-10 21:02 ` [PATCH v4 07/14] perf/x86/amd: make Zen3 branch sampling opt-in Stephane Eranian
2021-12-10 21:02 ` Stephane Eranian [this message]
2021-12-13 5:56 ` [PATCH v4 08/14] ACPI: add perf low power callback kernel test robot
2021-12-13 22:40 ` kernel test robot
2021-12-23 13:11 ` Like Xu
2021-12-10 21:02 ` [PATCH v4 09/14] perf/x86/amd: add idle hooks for branch sampling Stephane Eranian
2021-12-10 21:02 ` [PATCH v4 10/14] perf tools: add branch-brs as a new event Stephane Eranian
2021-12-10 21:02 ` [PATCH v4 11/14] perf evsel: Make evsel__env always return a valid env Stephane Eranian
2021-12-10 21:02 ` [PATCH v4 12/14] perf tools: Improve IBS error handling Stephane Eranian
2021-12-10 21:02 ` [PATCH v4 13/14] perf tools: Improve error handling of AMD Branch Sampling Stephane Eranian
2021-12-10 21:02 ` [PATCH v4 14/14] perf report: add addr_from/addr_to sort dimensions Stephane Eranian
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