CoreSight

coresight@lists.linaro.org

5 participants
2513 discussions

Re: [PATCH] coresight: cti: Remove unused variables in cti_{dis,en}able_hw()

by Suzuki K Poulose

Hi Nathan On 24/10/2022 16:12, Nathan Chancellor wrote: > Clean up the following warnings, as the variables are no longer used. > > drivers/hwtracing/coresight/coresight-cti-core.c:93:17: warning: unused variable 'dev' [-Wunused-variable] > struct device *dev = &drvdata->csdev->dev; > ^ > drivers/hwtracing/coresight/coresight-cti-core.c:154:17: warning: unused variable 'dev' [-Wunused-variable] > struct device *dev = &drvdata->csdev->dev; > ^ > 2 warnings generated. > > Fixes: 665c157e0204 ("coresight: cti: Fix hang in cti_disable_hw()") > Signed-off-by: Nathan Chancellor <nathan(a)kernel.org> Thanks for your patch, this is now reverted upstream. I have queued a patch locally to sqaush the changes and plan to push it once the revert lands upstream. Thanks Suzuki

3 years

[PATCH V10 0/2] Add support for UltraSoc System Memory Buffer

by Junhao He

Add support for UltraSoc System Memory Buffer. Change since v9: - Update the Contact tag in SMB document. - Replace the spinlock with mutex. - Do some clean-ups in "smb_enable()" and "smb_release()". - Use classic memory mapped interface. - Link: https://lore.kernel.org/linux-arm-kernel/20220818132231.28240-1-hejunhao3@h… Change since v8: - Insert a blank line at the end of the config tag in Kconfig. - Fix the "llseek" initialization. - Link: https://lore.kernel.org/linux-arm-kernel/20220816131634.38195-1-hejunhao3@h… Change since v7: - Use the macros for register bit flags and numbers of resource. - Fix punctuation. - Update the Date tag and the KernelVersion tag in the document. - Link: https://lore.kernel.org/lkml/20220712091353.34540-1-hejunhao3@huawei.com/ Change since v6: - Modify the code style and driver description according to Suzuki's comment. - Modify configuration of "drvdata->reading", to void problems in open/read concurrency scenario. - Rename the macro of "SMB_FLOW_MASK". - Use the "handle->head" to determine the page number and offset. - Link: https://lore.kernel.org/linux-arm-kernel/20220606130223.57354-1-liuqi115@hu… Change since v5: - Address the comments from Suzuki, add some comments in SMB document, and modify configuration of "drvdata->reading", to void problems in multi-core concurrency scenario - Link: https://lore.kernel.org/linux-arm-kernel/20220416083953.52610-1-liuqi115@hu… Change since v4: - Add a simple document of SMB driver according to Suzuki's comment. - Address the comments from Suzuki. - Link: https://lore.kernel.org/linux-arm-kernel/20220128061755.31909-1-liuqi115@hu… Change since v3: - Modify the file header according to community specifications. - Address the comments from Mathieu. - Link: https://lore.kernel.org/linux-arm-kernel/20211118110016.40398-1-liuqi115@hu… Change since v2: - Move ultrasoc driver to drivers/hwtracing/coresight. - Link: https://lists.linaro.org/pipermail/coresight/2021-November/007310.html Change since v1: - Drop the document of UltraSoc according to Mathieu's comment. - Add comments to explain some private hardware settings. - Address the comments from Mathieu. - Link: https://lists.linaro.org/pipermail/coresight/2021-August/006842.html Change since RFC: - Move driver to drivers/hwtracing/coresight/ultrasoc. - Remove ultrasoc-axi-com.c, as AXI-COM doesn't need to be configured in basic tracing function. - Remove ultrasoc.c as SMB does not need to register with the ultrasoc core. - Address the comments from Mathieu and Suzuki. - Link: https://lists.linaro.org/pipermail/coresight/2021-June/006535.html Qi Liu (2): drivers/coresight: Add UltraSoc System Memory Buffer driver Documentation: Add document for UltraSoc SMB drivers .../sysfs-bus-coresight-devices-ultra_smb | 31 + .../trace/coresight/ultrasoc-smb.rst | 80 +++ drivers/hwtracing/coresight/Kconfig | 11 + drivers/hwtracing/coresight/Makefile | 1 + drivers/hwtracing/coresight/ultrasoc-smb.c | 635 ++++++++++++++++++ drivers/hwtracing/coresight/ultrasoc-smb.h | 116 ++++ 6 files changed, 874 insertions(+) create mode 100644 Documentation/ABI/testing/sysfs-bus-coresight-devices-ultra_smb create mode 100644 Documentation/trace/coresight/ultrasoc-smb.rst create mode 100644 drivers/hwtracing/coresight/ultrasoc-smb.c create mode 100644 drivers/hwtracing/coresight/ultrasoc-smb.h -- 2.33.0

3 years

[GIT PULL v2] coresight: Fixes for v6.1

by Suzuki K Poulose

Hi Greg, Please find a couple of fixes for coresight subsystem. I have addressed your comments from the previous post : - Removed 2 patches that were not really critical for v6.1 - Fixes tag is added - Fixed git repo URL. Please pull. Thanks Suzuki The following changes since commit 9abf2313adc1ca1b6180c508c25f22f9395cc780: Linux 6.1-rc1 (2022-10-16 15:36:24 -0700) are available in the Git repository at: git://git.kernel.org/pub/scm/linux/kernel/git/coresight/linux.git tags/coresight-fixes-v6.1-1 for you to fetch changes up to 665c157e0204176023860b51a46528ba0ba62c33: coresight: cti: Fix hang in cti_disable_hw() (2022-10-20 22:34:23 +0100) ---------------------------------------------------------------- coresight: Fixes for v6.1 Fixes for coresight drivers for v6.1 - Fix possible deadlock CTI mutexes (LOCKDEP) - Fix hang in CTI with runtime power management Signed-off-by: Suzuki K Poulose <suzuki.poulose(a)arm.com> ---------------------------------------------------------------- James Clark (1): coresight: cti: Fix hang in cti_disable_hw() Sudeep Holla (1): coresight: Fix possible deadlock with lock dependency drivers/hwtracing/coresight/coresight-core.c | 7 ++++--- drivers/hwtracing/coresight/coresight-cti-core.c | 8 +++----- 2 files changed, 7 insertions(+), 8 deletions(-)

3 years

Re: [GIT PULL] coresight: Fixes for v6.1

by Suzuki K Poulose

Greg On 20/10/2022 09:43, Greg KH wrote: > On Thu, Oct 20, 2022 at 10:41:07AM +0200, Greg KH wrote: >> On Wed, Oct 19, 2022 at 10:31:18PM +0100, Suzuki K Poulose wrote: >>> Greg, >>> >>> Please find some of the fixes coresight drivers for v6.1. >>> The important ones are a couple for the CTI driver which >>> could cause hangs on a system with tracing. >>> >>> Please pull, >>> Suzuki >>> >>> >>> The following changes since commit 9abf2313adc1ca1b6180c508c25f22f9395cc780: >>> >>> Linux 6.1-rc1 (2022-10-16 15:36:24 -0700) >>> >>> are available in the Git repository at: >>> >>> git.kernel.org/pub/scm/linux/kernel/git/coresight/linux.git tags/coresight-fixes-v6.1-1 > > Nit, this is not a valid URL to pull from. Please fix for your next > submission. > > >>> >>> for you to fetch changes up to 262068519b562dcf73297b2a75fb850342ba99e5: >>> >>> coresight: cti: Fix hang in cti_disable_hw() (2022-10-19 15:47:53 +0100) >>> >>> ---------------------------------------------------------------- >>> coresight: Fixes for v6.1 >>> >>> Fixes for coresight drivers for v6.1 >>> >>> - Fix possible deadlock CTI mutexes (LOCKDEP) >>> - Fix hang in CTI with runtime power management >>> - Fix grammars in a comment >>> - Use sysfs_emit() instead of scnprintf() >> >> Sorry, but patch 2 here, doing the sysfs_emit() is not allowed. That >> user has been banned from lore.kernel.org for sending patches through a >> random gmail account with no verification that they really are from ZTE >> at all. Until we get proof from ZTE that this developer really is who >> they say they are, we can't take patches from them. >> >> Please do not take any future patches from anyone sending from gmail.com >> that purports to be from ZTE until this is worked out. >> >> Also, it's not a "fix" at all, and shouldn't be needed for 6.1-final at >> all. >> >> I'll just drop that patch and regenerate this on my end to get the 3 >> other fixes merged in here properly. > > I'll also drop the grammer "fix" in here too, that's not needed for > 6.1-final. > > Also, the two other commits in here, do they need to go to stable trees? > I see no "Fixes:" or "cc: stable" markings on them at all. > > How about you just regenerate the pull request with just the 2 patches > here that are valid and put proper Fixes: tags on them, then send me a > fixed up pull request. Sure, will do that. Thanks for the feedback ! I will take care of your points in the future submissions. Cheers Suzuki

3 years

[GIT PULL] coresight: Fixes for v6.1

by Suzuki K Poulose

Greg, Please find some of the fixes coresight drivers for v6.1. The important ones are a couple for the CTI driver which could cause hangs on a system with tracing. Please pull, Suzuki The following changes since commit 9abf2313adc1ca1b6180c508c25f22f9395cc780: Linux 6.1-rc1 (2022-10-16 15:36:24 -0700) are available in the Git repository at: git.kernel.org/pub/scm/linux/kernel/git/coresight/linux.git tags/coresight-fixes-v6.1-1 for you to fetch changes up to 262068519b562dcf73297b2a75fb850342ba99e5: coresight: cti: Fix hang in cti_disable_hw() (2022-10-19 15:47:53 +0100) ---------------------------------------------------------------- coresight: Fixes for v6.1 Fixes for coresight drivers for v6.1 - Fix possible deadlock CTI mutexes (LOCKDEP) - Fix hang in CTI with runtime power management - Fix grammars in a comment - Use sysfs_emit() instead of scnprintf() Signed-off-by: Suzuki K Poulose <suzuki.poulose(a)arm.com> ---------------------------------------------------------------- James Clark (1): coresight: cti: Fix hang in cti_disable_hw() Jilin Yuan (1): coresight: etm4x: fix repeated words in comments Sudeep Holla (1): coresight: Fix possible deadlock with lock dependency zhang songyi (1): coresight: use sysfs_emit() to instead of scnprintf() drivers/hwtracing/coresight/coresight-core.c | 7 ++++--- drivers/hwtracing/coresight/coresight-cti-core.c | 8 +++----- drivers/hwtracing/coresight/coresight-etm4x-core.c | 2 +- drivers/hwtracing/coresight/coresight-stm.c | 8 ++++---- 4 files changed, 12 insertions(+), 13 deletions(-)

3 years

[PATCH v9 00/13] perf: test: Add trace data quality tests for CoreSight

by carsten.haitzler＠foss.arm.com

From: Carsten Haitzler <carsten.haitzler(a)arm.com> This series adds more test cases to perf test as well as new infrastructure for testing coresight data quality to ensure the data coming out of the kernel via perf actually contains useful information. Signed-off-by: Carsten Haitzler <carsten.haitzler(a)arm.com> Carsten Haitzler (13): perf test: Add CoreSight shell lib shared code for future tests perf test: Add build infra for perf test tools for CoreSight tests perf test: Add asm pureloop test tool perf test: Add asm pureloop test shell script perf test: Add git ignore for perf data generated by the CoreSight tests perf test: Add memcpy thread test tool perf test: Add memcpy thread test shell script perf test: Add thread loop test tool perf test: Add thread loop test shell scripts perf test: Add unroll thread test tool perf test: Add unroll thread test shell script perf test: Add git ignore for tmp and output files of CoreSight tests perf test: Add relevant documentation about CoreSight testing .../trace/coresight/coresight-perf.rst | 158 ++++++++++++++++++ MAINTAINERS | 1 + tools/perf/.gitignore | 6 +- .../perf/Documentation/perf-arm-coresight.txt | 5 + tools/perf/Makefile.config | 2 + tools/perf/Makefile.perf | 15 +- tools/perf/tests/shell/coresight/Makefile | 29 ++++ .../tests/shell/coresight/Makefile.miniconfig | 14 ++ .../tests/shell/coresight/asm_pure_loop.sh | 18 ++ .../shell/coresight/asm_pure_loop/.gitignore | 1 + .../shell/coresight/asm_pure_loop/Makefile | 34 ++++ .../coresight/asm_pure_loop/asm_pure_loop.S | 28 ++++ .../shell/coresight/memcpy_thread/.gitignore | 1 + .../shell/coresight/memcpy_thread/Makefile | 33 ++++ .../coresight/memcpy_thread/memcpy_thread.c | 79 +++++++++ .../shell/coresight/memcpy_thread_16k_10.sh | 18 ++ .../shell/coresight/thread_loop/.gitignore | 1 + .../shell/coresight/thread_loop/Makefile | 33 ++++ .../shell/coresight/thread_loop/thread_loop.c | 86 ++++++++++ .../coresight/thread_loop_check_tid_10.sh | 19 +++ .../coresight/thread_loop_check_tid_2.sh | 19 +++ .../coresight/unroll_loop_thread/.gitignore | 1 + .../coresight/unroll_loop_thread/Makefile | 33 ++++ .../unroll_loop_thread/unroll_loop_thread.c | 74 ++++++++ .../shell/coresight/unroll_loop_thread_10.sh | 18 ++ tools/perf/tests/shell/lib/coresight.sh | 132 +++++++++++++++ 26 files changed, 854 insertions(+), 4 deletions(-) create mode 100644 Documentation/trace/coresight/coresight-perf.rst create mode 100644 tools/perf/Documentation/perf-arm-coresight.txt create mode 100644 tools/perf/tests/shell/coresight/Makefile create mode 100644 tools/perf/tests/shell/coresight/Makefile.miniconfig create mode 100755 tools/perf/tests/shell/coresight/asm_pure_loop.sh create mode 100644 tools/perf/tests/shell/coresight/asm_pure_loop/.gitignore create mode 100644 tools/perf/tests/shell/coresight/asm_pure_loop/Makefile create mode 100644 tools/perf/tests/shell/coresight/asm_pure_loop/asm_pure_loop.S create mode 100644 tools/perf/tests/shell/coresight/memcpy_thread/.gitignore create mode 100644 tools/perf/tests/shell/coresight/memcpy_thread/Makefile create mode 100644 tools/perf/tests/shell/coresight/memcpy_thread/memcpy_thread.c create mode 100755 tools/perf/tests/shell/coresight/memcpy_thread_16k_10.sh create mode 100644 tools/perf/tests/shell/coresight/thread_loop/.gitignore create mode 100644 tools/perf/tests/shell/coresight/thread_loop/Makefile create mode 100644 tools/perf/tests/shell/coresight/thread_loop/thread_loop.c create mode 100755 tools/perf/tests/shell/coresight/thread_loop_check_tid_10.sh create mode 100755 tools/perf/tests/shell/coresight/thread_loop_check_tid_2.sh create mode 100644 tools/perf/tests/shell/coresight/unroll_loop_thread/.gitignore create mode 100644 tools/perf/tests/shell/coresight/unroll_loop_thread/Makefile create mode 100644 tools/perf/tests/shell/coresight/unroll_loop_thread/unroll_loop_thread.c create mode 100755 tools/perf/tests/shell/coresight/unroll_loop_thread_10.sh create mode 100644 tools/perf/tests/shell/lib/coresight.sh -- 2.32.0

3 years

[PATCH] coresight: cti: Fix hang in cti_disable_hw()

by James Clark

cti_enable_hw() and cti_disable_hw() are called from an atomic context so shouldn't use runtime PM because it can result in a sleep when communicating with firmware. Since commit 3c6656337852 ("Revert "firmware: arm_scmi: Add clock management to the SCMI power domain""), this causes a hang on Juno when running the Perf Coresight tests or running this command: perf record -e cs_etm//u -- ls This was also missed until the revert commit because pm_runtime_put() was called with the wrong device until commit 692c9a499b28 ("coresight: cti: Correct the parameter for pm_runtime_put") With lock and scheduler debugging enabled the following is output: coresight cti_sys0: cti_enable_hw -- dev:cti_sys0 parent: 20020000.cti BUG: sleeping function called from invalid context at drivers/base/power/runtime.c:1151 in_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 330, name: perf-exec preempt_count: 2, expected: 0 RCU nest depth: 0, expected: 0 INFO: lockdep is turned off. irq event stamp: 0 hardirqs last enabled at (0): [<0000000000000000>] 0x0 hardirqs last disabled at (0): [<ffff80000822b394>] copy_process+0xa0c/0x1948 softirqs last enabled at (0): [<ffff80000822b394>] copy_process+0xa0c/0x1948 softirqs last disabled at (0): [<0000000000000000>] 0x0 CPU: 3 PID: 330 Comm: perf-exec Not tainted 6.0.0-00053-g042116d99298 #7 Hardware name: ARM LTD ARM Juno Development Platform/ARM Juno Development Platform, BIOS EDK II Sep 13 2022 Call trace: dump_backtrace+0x134/0x140 show_stack+0x20/0x58 dump_stack_lvl+0x8c/0xb8 dump_stack+0x18/0x34 __might_resched+0x180/0x228 __might_sleep+0x50/0x88 __pm_runtime_resume+0xac/0xb0 cti_enable+0x44/0x120 coresight_control_assoc_ectdev+0xc0/0x150 coresight_enable_path+0xb4/0x288 etm_event_start+0x138/0x170 etm_event_add+0x48/0x70 event_sched_in.isra.122+0xb4/0x280 merge_sched_in+0x1fc/0x3d0 visit_groups_merge.constprop.137+0x16c/0x4b0 ctx_sched_in+0x114/0x1f0 perf_event_sched_in+0x60/0x90 ctx_resched+0x68/0xb0 perf_event_exec+0x138/0x508 begin_new_exec+0x52c/0xd40 load_elf_binary+0x6b8/0x17d0 bprm_execve+0x360/0x7f8 do_execveat_common.isra.47+0x218/0x238 __arm64_sys_execve+0x48/0x60 invoke_syscall+0x4c/0x110 el0_svc_common.constprop.4+0xfc/0x120 do_el0_svc+0x34/0xc0 el0_svc+0x40/0x98 el0t_64_sync_handler+0x98/0xc0 el0t_64_sync+0x170/0x174 Fix the issue by removing the runtime PM calls completely. They are not needed here because it must have already been done when building the path for a trace. Fixes: 835d722ba10a ("coresight: cti: Initial CoreSight CTI Driver") Reported-by: Aishwarya TCV <Aishwarya.TCV(a)arm.com> Reported-by: Cristian Marussi <Cristian.Marussi(a)arm.com> Signed-off-by: Suzuki Poulose <Suzuki.Poulose(a)arm.com> Signed-off-by: James Clark <james.clark(a)arm.com> --- drivers/hwtracing/coresight/coresight-cti-core.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/drivers/hwtracing/coresight/coresight-cti-core.c b/drivers/hwtracing/coresight/coresight-cti-core.c index 8988b2ed2ea6..c5f7fc4e2552 100644 --- a/drivers/hwtracing/coresight/coresight-cti-core.c +++ b/drivers/hwtracing/coresight/coresight-cti-core.c @@ -94,7 +94,6 @@ static int cti_enable_hw(struct cti_drvdata *drvdata) unsigned long flags; int rc = 0; - pm_runtime_get_sync(dev->parent); spin_lock_irqsave(&drvdata->spinlock, flags); /* no need to do anything if enabled or unpowered*/ @@ -119,7 +118,6 @@ static int cti_enable_hw(struct cti_drvdata *drvdata) /* cannot enable due to error */ cti_err_not_enabled: spin_unlock_irqrestore(&drvdata->spinlock, flags); - pm_runtime_put(dev->parent); return rc; } @@ -175,7 +173,6 @@ static int cti_disable_hw(struct cti_drvdata *drvdata) coresight_disclaim_device_unlocked(csdev); CS_LOCK(drvdata->base); spin_unlock(&drvdata->spinlock); - pm_runtime_put(dev->parent); return 0; /* not disabled this call */ -- 2.28.0

3 years

Re: [PATCH] coresight: etm4x: fix repeated words in comments

by Suzuki K Poulose

On 19/10/2022 13:49, Jilin Yuan wrote: > Delete the redundant word 'the'. > > Signed-off-by: Jilin Yuan <yuanjilin(a)cdjrlc.com> Thanks, Queued. > --- > drivers/hwtracing/coresight/coresight-etm4x-core.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c > index 80fefaba58ee..849c563cfc65 100644 > --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c > +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c > @@ -1478,7 +1478,7 @@ static int etm4_set_event_filters(struct etmv4_drvdata *drvdata, > /* > * If filters::ssstatus == 1, trace acquisition was > * started but the process was yanked away before the > - * the stop address was hit. As such the start/stop > + * stop address was hit. As such the start/stop > * logic needs to be re-started so that tracing can > * resume where it left. > *

3 years

Re: [PATCH v9 13/13] perf test: Add relevant documentation about CoreSight testing

by Carsten Haitzler

This is weird. This shouldn't be making its way into any man page at all. It's just a file pointing people at other parts of the kernel tree for docs (because when I looked for docs - i found nothing for any kind of getting started guide - I put something here as this was the obvious place for perf related docs for testing - but was told to put the docs elsewhere in core kernel documentation, but I put a reference here for those who follow after to be able to more easily find it). There is some rule somewhere it seems that makes anything perf-*.txt into a man page. I need to rename this file it seems. On 10/11/22 08:27, Sven Schnelle wrote: > Hi Carsten, > > carsten.haitzler(a)foss.arm.com writes: > >> From: Carsten Haitzler <carsten.haitzler(a)arm.com> >> >> Add/improve documentation helping people get started with CoreSight and >> perf as well as describe the testing and how it works. >> >> Cc: linux-doc(a)vger.kernel.org >> Signed-off-by: Carsten Haitzler <carsten.haitzler(a)arm.com> >> --- >> .../trace/coresight/coresight-perf.rst | 158 ++++++++++++++++++ >> .../perf/Documentation/perf-arm-coresight.txt | 5 + >> 2 files changed, 163 insertions(+) >> create mode 100644 Documentation/trace/coresight/coresight-perf.rst >> create mode 100644 tools/perf/Documentation/perf-arm-coresight.txt >> > > Investigating a rpm build failure i see the following error with next-20221011: > > % cd tools/perf/Documentation > % make O=/home/svens/linux-build/ man V=1 > rm -f /home/svens/linux-build/perf-arm-coresight.xml+ /home/svens/linux-build/perf-arm-coresight.xml && \ > asciidoc -b docbook -d manpage \ > --unsafe -f asciidoc.conf -aperf_version= \ > -aperf_date=2022-10-06 \ > -o /home/svens/linux-build/perf-arm-coresight.xml+ perf-arm-coresight.txt && \ > mv /home/svens/linux-build/perf-arm-coresight.xml+ /home/svens/linux-build/perf-arm-coresight.xml > asciidoc: FAILED: manpage document title is mandatory > make: *** [Makefile:266: /home/svens/linux-build/perf-arm-coresight.xml] Error 1 > > Can you please fix this? > > Thanks!

3 years

[PATCH v10 13/13] perf test: Add relevant documentation about CoreSight testing

by carsten.haitzler＠foss.arm.com

From: Carsten Haitzler <carsten.haitzler(a)arm.com> Add/improve documentation helping people get started with CoreSight and perf as well as describe the testing and how it works. Cc: linux-doc(a)vger.kernel.org Signed-off-by: Carsten Haitzler <carsten.haitzler(a)arm.com> --- .../trace/coresight/coresight-perf.rst | 158 ++++++++++++++++++ tools/perf/Documentation/arm-coresight.txt | 5 + 2 files changed, 163 insertions(+) create mode 100644 Documentation/trace/coresight/coresight-perf.rst create mode 100644 tools/perf/Documentation/arm-coresight.txt diff --git a/Documentation/trace/coresight/coresight-perf.rst b/Documentation/trace/coresight/coresight-perf.rst new file mode 100644 index 000000000000..d087aae7d492 --- /dev/null +++ b/Documentation/trace/coresight/coresight-perf.rst @@ -0,0 +1,158 @@ +.. SPDX-License-Identifier: GPL-2.0 + +================ +CoreSight - Perf +================ + + :Author: Carsten Haitzler <carsten.haitzler(a)arm.com> + :Date: June 29th, 2022 + +Perf is able to locally access CoreSight trace data and store it to the +output perf data files. This data can then be later decoded to give the +instructions that were traced for debugging or profiling purposes. You +can log such data with a perf record command like:: + + perf record -e cs_etm//u testbinary + +This would run some test binary (testbinary) until it exits and record +a perf.data trace file. That file would have AUX sections if CoreSight +is working correctly. You can dump the content of this file as +readable text with a command like:: + + perf report --stdio --dump -i perf.data + +You should find some sections of this file have AUX data blocks like:: + + 0x1e78 [0x30]: PERF_RECORD_AUXTRACE size: 0x11dd0 offset: 0 ref: 0x1b614fc1061b0ad1 idx: 0 tid: 531230 cpu: -1 + + . ... CoreSight ETM Trace data: size 73168 bytes + Idx:0; ID:10; I_ASYNC : Alignment Synchronisation. + Idx:12; ID:10; I_TRACE_INFO : Trace Info.; INFO=0x0 { CC.0 } + Idx:17; ID:10; I_ADDR_L_64IS0 : Address, Long, 64 bit, IS0.; Addr=0x0000000000000000; + Idx:26; ID:10; I_TRACE_ON : Trace On. + Idx:27; ID:10; I_ADDR_CTXT_L_64IS0 : Address & Context, Long, 64 bit, IS0.; Addr=0x0000FFFFB6069140; Ctxt: AArch64,EL0, NS; + Idx:38; ID:10; I_ATOM_F6 : Atom format 6.; EEEEEEEEEEEEEEEEEEEEEEEE + Idx:39; ID:10; I_ATOM_F6 : Atom format 6.; EEEEEEEEEEEEEEEEEEEEEEEE + Idx:40; ID:10; I_ATOM_F6 : Atom format 6.; EEEEEEEEEEEEEEEEEEEEEEEE + Idx:41; ID:10; I_ATOM_F6 : Atom format 6.; EEEEEEEEEEEN + ... + +If you see these above, then your system is tracing CoreSight data +correctly. + +To compile perf with CoreSight support in the tools/perf directory do:: + + make CORESIGHT=1 + +This requires OpenCSD to build. You may install distribution packages +for the support such as libopencsd and libopencsd-dev or download it +and build yourself. Upstream OpenCSD is located at: + + https://github.com/Linaro/OpenCSD + +For complete information on building perf with CoreSight support and +more extensive usage look at: + + https://github.com/Linaro/OpenCSD/blob/master/HOWTO.md + + +Kernel CoreSight Support +------------------------ + +You will also want CoreSight support enabled in your kernel config. +Ensure it is enabled with:: + + CONFIG_CORESIGHT=y + +There are various other CoreSight options you probably also want +enabled like:: + + CONFIG_CORESIGHT_LINKS_AND_SINKS=y + CONFIG_CORESIGHT_LINK_AND_SINK_TMC=y + CONFIG_CORESIGHT_CATU=y + CONFIG_CORESIGHT_SINK_TPIU=y + CONFIG_CORESIGHT_SINK_ETBV10=y + CONFIG_CORESIGHT_SOURCE_ETM4X=y + CONFIG_CORESIGHT_CTI=y + CONFIG_CORESIGHT_CTI_INTEGRATION_REGS=y + +Please refer to the kernel configuration help for more information. + +Perf test - Verify kernel and userspace perf CoreSight work +----------------------------------------------------------- + +When you run perf test, it will do a lot of self tests. Some of those +tests will cover CoreSight (only if enabled and on ARM64). You +generally would run perf test from the tools/perf directory in the +kernel tree. Some tests will check some internal perf support like: + + Check Arm CoreSight trace data recording and synthesized samples + Check Arm SPE trace data recording and synthesized samples + +Some others will actually use perf record and some test binaries that +are in tests/shell/coresight and will collect traces to ensure a +minimum level of functionality is met. The scripts that launch these +tests are in the same directory. These will all look like: + + CoreSight / ASM Pure Loop + CoreSight / Memcpy 16k 10 Threads + CoreSight / Thread Loop 10 Threads - Check TID + etc. + +These perf record tests will not run if the tool binaries do not exist +in tests/shell/coresight/\*/ and will be skipped. If you do not have +CoreSight support in hardware then either do not build perf with +CoreSight support or remove these binaries in order to not have these +tests fail and have them skip instead. + +These tests will log historical results in the current working +directory (e.g. tools/perf) and will be named stats-\*.csv like: + + stats-asm_pure_loop-out.csv + stats-memcpy_thread-16k_10.csv + ... + +These statistic files log some aspects of the AUX data sections in +the perf data output counting some numbers of certain encodings (a +good way to know that it's working in a very simple way). One problem +with CoreSight is that given a large enough amount of data needing to +be logged, some of it can be lost due to the processor not waking up +in time to read out all the data from buffers etc.. You will notice +that the amount of data collected can vary a lot per run of perf test. +If you wish to see how this changes over time, simply run perf test +multiple times and all these csv files will have more and more data +appended to it that you can later examine, graph and otherwise use to +figure out if things have become worse or better. + +This means sometimes these tests fail as they don't capture all the +data needed. This is about tracking quality and amount of data +produced over time and to see when changes to the Linux kernel improve +quality of traces. + +Be aware that some of these tests take quite a while to run, specifically +in processing the perf data file and dumping contents to then examine what +is inside. + +You can change where these csv logs are stored by setting the +PERF_TEST_CORESIGHT_STATDIR environment variable before running perf +test like:: + + export PERF_TEST_CORESIGHT_STATDIR=/var/tmp + perf test + +They will also store resulting perf output data in the current +directory for later inspection like:: + + perf-asm_pure_loop-out.data + perf-memcpy_thread-16k_10.data + ... + +You can alter where the perf data files are stored by setting the +PERF_TEST_CORESIGHT_DATADIR environment variable such as:: + + PERF_TEST_CORESIGHT_DATADIR=/var/tmp + perf test + +You may wish to set these above environment variables if you wish to +keep the output of tests outside of the current working directory for +longer term storage and examination. diff --git a/tools/perf/Documentation/arm-coresight.txt b/tools/perf/Documentation/arm-coresight.txt new file mode 100644 index 000000000000..c117fc50a2a9 --- /dev/null +++ b/tools/perf/Documentation/arm-coresight.txt @@ -0,0 +1,5 @@ +Arm CoreSight Support +===================== + +For full documentation, see Documentation/trace/coresight/coresight-perf.rst +in the kernel tree. -- 2.32.0

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