From: Sasha Levin <sashal@kernel.org> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>, Michael Ellerman <mpe@ellerman.id.au>, Sasha Levin <sashal@kernel.org>, linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 5.10 17/47] powerpc/perf: Record counter overflow always if SAMPLE_IP is unset Date: Tue, 2 Mar 2021 06:56:16 -0500 [thread overview] Message-ID: <20210302115646.62291-17-sashal@kernel.org> (raw) In-Reply-To: <20210302115646.62291-1-sashal@kernel.org> From: Athira Rajeev <atrajeev@linux.vnet.ibm.com> [ Upstream commit d137845c973147a22622cc76c7b0bc16f6206323 ] While sampling for marked events, currently we record the sample only if the SIAR valid bit of Sampled Instruction Event Register (SIER) is set. SIAR_VALID bit is used for fetching the instruction address from Sampled Instruction Address Register(SIAR). But there are some usecases, where the user is interested only in the PMU stats at each counter overflow and the exact IP of the overflow event is not required. Dropping SIAR invalid samples will fail to record some of the counter overflows in such cases. Example of such usecase is dumping the PMU stats (event counts) after some regular amount of instructions/events from the userspace (ex: via ptrace). Here counter overflow is indicated to userspace via signal handler, and captured by monitoring and enabling I/O signaling on the event file descriptor. In these cases, we expect to get sample/overflow indication after each specified sample_period. Perf event attribute will not have PERF_SAMPLE_IP set in the sample_type if exact IP of the overflow event is not requested. So while profiling if SAMPLE_IP is not set, just record the counter overflow irrespective of SIAR_VALID check. Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> [mpe: Reflow comment and if formatting] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1612516492-1428-1-git-send-email-atrajeev@linux.vnet.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org> --- arch/powerpc/perf/core-book3s.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 43599e671d38..d84ab867b986 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -2112,7 +2112,17 @@ static void record_and_restart(struct perf_event *event, unsigned long val, left += period; if (left <= 0) left = period; - record = siar_valid(regs); + + /* + * If address is not requested in the sample via + * PERF_SAMPLE_IP, just record that sample irrespective + * of SIAR valid check. + */ + if (event->attr.sample_type & PERF_SAMPLE_IP) + record = siar_valid(regs); + else + record = 1; + event->hw.last_period = event->hw.sample_period; } if (left < 0x80000000LL) @@ -2130,9 +2140,10 @@ static void record_and_restart(struct perf_event *event, unsigned long val, * MMCR2. Check attr.exclude_kernel and address to drop the sample in * these cases. */ - if (event->attr.exclude_kernel && record) - if (is_kernel_addr(mfspr(SPRN_SIAR))) - record = 0; + if (event->attr.exclude_kernel && + (event->attr.sample_type & PERF_SAMPLE_IP) && + is_kernel_addr(mfspr(SPRN_SIAR))) + record = 0; /* * Finally record data if requested. -- 2.30.1
WARNING: multiple messages have this Message-ID (diff)
From: Sasha Levin <sashal@kernel.org> To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Sasha Levin <sashal@kernel.org>, Athira Rajeev <atrajeev@linux.vnet.ibm.com>, linuxppc-dev@lists.ozlabs.org Subject: [PATCH AUTOSEL 5.10 17/47] powerpc/perf: Record counter overflow always if SAMPLE_IP is unset Date: Tue, 2 Mar 2021 06:56:16 -0500 [thread overview] Message-ID: <20210302115646.62291-17-sashal@kernel.org> (raw) In-Reply-To: <20210302115646.62291-1-sashal@kernel.org> From: Athira Rajeev <atrajeev@linux.vnet.ibm.com> [ Upstream commit d137845c973147a22622cc76c7b0bc16f6206323 ] While sampling for marked events, currently we record the sample only if the SIAR valid bit of Sampled Instruction Event Register (SIER) is set. SIAR_VALID bit is used for fetching the instruction address from Sampled Instruction Address Register(SIAR). But there are some usecases, where the user is interested only in the PMU stats at each counter overflow and the exact IP of the overflow event is not required. Dropping SIAR invalid samples will fail to record some of the counter overflows in such cases. Example of such usecase is dumping the PMU stats (event counts) after some regular amount of instructions/events from the userspace (ex: via ptrace). Here counter overflow is indicated to userspace via signal handler, and captured by monitoring and enabling I/O signaling on the event file descriptor. In these cases, we expect to get sample/overflow indication after each specified sample_period. Perf event attribute will not have PERF_SAMPLE_IP set in the sample_type if exact IP of the overflow event is not requested. So while profiling if SAMPLE_IP is not set, just record the counter overflow irrespective of SIAR_VALID check. Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> [mpe: Reflow comment and if formatting] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1612516492-1428-1-git-send-email-atrajeev@linux.vnet.ibm.com Signed-off-by: Sasha Levin <sashal@kernel.org> --- arch/powerpc/perf/core-book3s.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/arch/powerpc/perf/core-book3s.c b/arch/powerpc/perf/core-book3s.c index 43599e671d38..d84ab867b986 100644 --- a/arch/powerpc/perf/core-book3s.c +++ b/arch/powerpc/perf/core-book3s.c @@ -2112,7 +2112,17 @@ static void record_and_restart(struct perf_event *event, unsigned long val, left += period; if (left <= 0) left = period; - record = siar_valid(regs); + + /* + * If address is not requested in the sample via + * PERF_SAMPLE_IP, just record that sample irrespective + * of SIAR valid check. + */ + if (event->attr.sample_type & PERF_SAMPLE_IP) + record = siar_valid(regs); + else + record = 1; + event->hw.last_period = event->hw.sample_period; } if (left < 0x80000000LL) @@ -2130,9 +2140,10 @@ static void record_and_restart(struct perf_event *event, unsigned long val, * MMCR2. Check attr.exclude_kernel and address to drop the sample in * these cases. */ - if (event->attr.exclude_kernel && record) - if (is_kernel_addr(mfspr(SPRN_SIAR))) - record = 0; + if (event->attr.exclude_kernel && + (event->attr.sample_type & PERF_SAMPLE_IP) && + is_kernel_addr(mfspr(SPRN_SIAR))) + record = 0; /* * Finally record data if requested. -- 2.30.1
next prev parent reply other threads:[~2021-03-02 12:54 UTC|newest] Thread overview: 69+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-03-02 11:56 [PATCH AUTOSEL 5.10 01/47] i2c: rcar: faster irq code to minimize HW race condition Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 02/47] i2c: rcar: optimize cacheline " Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 03/47] scsi: ufs: Add a quirk to permit overriding UniPro defaults Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 04/47] scsi: ufs: WB is only available on LUN #0 to #7 Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 05/47] scsi: ufs: Introduce a quirk to allow only page-aligned sg entries Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 06/47] udf: fix silent AED tagLocation corruption Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 07/47] iommu/vt-d: Clear PRQ overflow only when PRQ is empty Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 08/47] mmc: mxs-mmc: Fix a resource leak in an error handling path in 'mxs_mmc_probe()' Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 09/47] mmc: sdhci-of-dwcmshc: set SDHCI_QUIRK2_PRESET_VALUE_BROKEN Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 10/47] mmc: mediatek: fix race condition between msdc_request_timeout and irq Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 11/47] mmc: sdhci-iproc: Add ACPI bindings for the RPi Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 16:16 ` Jeremy Linton 2021-03-02 16:16 ` Jeremy Linton 2021-03-12 22:12 ` Sasha Levin 2021-03-12 22:12 ` Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 12/47] Platform: OLPC: Fix probe error handling Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 13/47] powerpc/pci: Add ppc_md.discover_phbs() Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 14/47] HID: i2c-hid: Add I2C_HID_QUIRK_NO_IRQ_AFTER_RESET for ITE8568 EC on Voyo Winpad A15 Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 15/47] spi: stm32: make spurious and overrun interrupts visible Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 16/47] powerpc: improve handling of unrecoverable system reset Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` Sasha Levin [this message] 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 17/47] powerpc/perf: Record counter overflow always if SAMPLE_IP is unset Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 18/47] kunit: tool: fix unit test cleanup handling Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 19/47] HID: logitech-dj: add support for the new lightspeed connection iteration Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 20/47] powerpc/64: Fix stack trace not displaying final frame Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 21/47] iommu/amd: Fix performance counter initialization Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 22/47] clk: qcom: gdsc: Implement NO_RET_PERIPH flag Sasha Levin 2021-03-02 23:04 ` Stephen Boyd 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 23/47] sparc32: Limit memblock allocation to low memory Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 24/47] sparc64: Use arch_validate_flags() to validate ADI flag Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 25/47] ACPICA: Fix race in generic_serial_bus (I2C) and GPIO op_region parameter handling Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 26/47] Input: applespi - don't wait for responses to commands indefinitely Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 27/47] x86, build: use objtool mcount Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 28/47] PCI: xgene-msi: Fix race in installing chained irq handler Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 29/47] misc: eeprom_93xx46: Add quirk to support Microchip 93LC46B eeprom Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 30/47] PCI: mediatek: Add missing of_node_put() to fix reference leak Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 31/47] drivers/base: build kunit tests without structleak plugin Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 32/47] drm/msm/a5xx: Remove overwriting A5XX_PC_DBG_ECO_CNTL register Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 33/47] PCI/LINK: Remove bandwidth notification Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 34/47] ext4: don't try to processed freed blocks until mballoc is initialized Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 35/47] PCI: cadence: Retrain Link to work around Gen2 training defect Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 36/47] kbuild: clamp SUBLEVEL to 255 Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 37/47] PCI: Fix pci_register_io_range() memory leak Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 38/47] i40e: Fix memory leak in i40e_probe Sasha Levin 2021-03-02 11:56 ` [Intel-wired-lan] " Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 39/47] kasan: fix memory corruption in kasan_bitops_tags test Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 40/47] riscv: Get rid of MAX_EARLY_MAPPING_SIZE Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 41/47] s390/smp: __smp_rescan_cpus() - move cpumask away from stack Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 42/47] drivers/base/memory: don't store phys_device in memory blocks Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 43/47] sysctl.c: fix underflow value setting risk in vm_table Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 44/47] scsi: libiscsi: Fix iscsi_prep_scsi_cmd_pdu() error handling Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 45/47] nbd: handle device refs for DESTROY_ON_DISCONNECT properly Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 46/47] scsi: target: core: Add cmd length set before cmd complete Sasha Levin 2021-03-02 11:56 ` Sasha Levin 2021-03-02 11:56 ` [PATCH AUTOSEL 5.10 47/47] scsi: target: core: Prevent underflow for service actions Sasha Levin
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