- 07 6月, 2016 1 次提交
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由 Andi Kleen 提交于
Add basic plumbing for TopDown in perf stat TopDown is intended to replace the frontend cycles idle/ backend cycles idle metrics in standard perf stat output. These metrics are not reliable in many workloads, due to out of order effects. This implements a new --topdown mode in perf stat (similar to --transaction) that measures the pipe line bottlenecks using standardized formulas. The measurement can be all done with 5 counters (one fixed counter) The result are four metrics: FrontendBound, BackendBound, BadSpeculation, Retiring that describe the CPU pipeline behavior on a high level. The full top down methology has many hierarchical metrics. This implementation only supports level 1 which can be collected without multiplexing. A full implementation of top down on top of perf is available in pmu-tools toplev. (http://github.com/andikleen/pmu-tools) The current version works on Intel Core CPUs starting with Sandy Bridge, and Atom CPUs starting with Silvermont. In principle the generic metrics should be also implementable on other out of order CPUs. TopDown level 1 uses a set of abstracted metrics which are generic to out of order CPU cores (although some CPUs may not implement all of them): topdown-total-slots Available slots in the pipeline topdown-slots-issued Slots issued into the pipeline topdown-slots-retired Slots successfully retired topdown-fetch-bubbles Pipeline gaps in the frontend topdown-recovery-bubbles Pipeline gaps during recovery from misspeculation These metrics then allow to compute four useful metrics: FrontendBound, BackendBound, Retiring, BadSpeculation. Add a new --topdown options to enable events. When --topdown is specified set up events for all topdown events supported by the kernel. Add topdown-* as a special case to the event parser, as is needed for all events containing -. The actual code to compute the metrics is in follow-on patches. v2: Use standard sysctl read function. v3: Move x86 specific code to arch/ v4: Enable --metric-only implicitly for topdown. v5: Add --single-thread option to not force per core mode v6: Fix output order of topdown metrics v7: Allow combining with -d v8: Remove --single-thread again v9: Rename functions, adding arch_ and topdown_. v10: Expand man page and describe TopDown better Paste intro into commit description. Print error when malloc fails. Signed-off-by: NAndi Kleen <ak@linux.intel.com> Acked-by: NJiri Olsa <jolsa@kernel.org> Link: http://lkml.kernel.org/r/1464119559-17203-1-git-send-email-andi@firstfloor.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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- 06 6月, 2016 1 次提交
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由 Andi Kleen 提交于
'perf test' tries to parse all entries in /sys/devices/cpu/events/. Ignore the special entries like '.scale', which cannot be directly parsed as an event. This patch assumes all files containing a '.' are special and can be ignored. Reported-by: NArnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: NAndi Kleen <ak@linux.intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Link: http://lkml.kernel.org/r/1465223766-29902-1-git-send-email-andi@firstfloor.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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- 04 6月, 2016 4 次提交
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由 He Kuang 提交于
There's a display inconsistency when there are multiple tracepoint events, some of which have the 'call-graph' config option set but the first one hasn't, i.e. the whole logic for call graph processing is enabled only if the first tracepoint event has call-graph set. For instance, if we record signal_deliver with call-graph and signal_generate without: $ perf record -g -a -e signal:signal_deliver -e signal:signal_generate/call-graph=no/ [ perf record: Captured and wrote 0.017 MB perf.data (2 samples) ] $ perf script kworker/u2:1 13 [000] 6563.875949: signal:signal_generate: sig=2 errno=0 code=128 comm=perf pid=1313 grp=1 res=0 ff61cc __send_signal+0x3ec ([kernel.kallsyms]) perf 1313 [000] 6563.877584: signal:signal_deliver: sig=2 errno=0 code=128 sa_handler=43115e sa_flags=14000000 7ffff314 get_signal+0x80007f0023a4 ([kernel.kallsyms]) 7fffe358 do_signal+0x80007f002028 ([kernel.kallsyms]) 7fffa5e8 exit_to_usermode_loop+0x80007f002053 ([kernel.kallsyms]) ... Then we exchange the order of these two events in commandline, and keep signal_generate without call-graph. $ perf record -g -a -e signal:signal_generate/call-graph=no/ -e signal:signal_deliver [ perf record: Captured and wrote 0.017 MB perf.data (2 samples) ] $ perf script kworker/u2:2 1314 [000] 6933.353060: signal:signal_generate: sig=2 errno=0 code=128 comm=perf pid=1321 grp=1 res=0 perf 1321 [000] 6933.353872: signal:signal_deliver: sig=2 errno=0 code=128 sa_handler=43115e sa_flags=14000000 This time, the callchain of the event signal_deliver disappeared. The problem is caused by that perf only checks for the first evsel in evlist and decides if callchain should be printed. This patch traverses all evsels in evlist to see if any of them have callchains, and shows the right result: $ perf script kworker/u2:2 1314 [000] 6933.353060: signal:signal_generate: sig=2 errno=0 code=128 comm=perf pid=1321 grp=1 res=0 ff61cc __send_signal+0x3ec ([kernel.kallsyms]) perf 1321 [000] 6933.353872: signal:signal_deliver: sig=2 errno=0 code=128 sa_handler=43115e sa_flags=14000000 7ffff314 get_signal+0x80007f0023a4 ([kernel.kallsyms]) 7fffe358 do_signal+0x80007f002028 ([kernel.kallsyms]) 7fffa5e8 exit_to_usermode_loop+0x80007f002053 ([kernel.kallsyms]) ... Signed-off-by: NHe Kuang <hekuang@huawei.com> Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/r/1463374279-97209-1-git-send-email-hekuang@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Lucas Stach 提交于
This fixes cross compilation of libapi. Signed-off-by: NLucas Stach <l.stach@pengutronix.de> Cc: Jiri Olsa <jolsa@kernel.org> Cc: kernel@pengutronix.de Cc: patchwork-lst@pengutronix.de Link: http://lkml.kernel.org/r/1458235670-27341-1-git-send-email-l.stach@pengutronix.deSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Wang Nan 提交于
If zalloc fail, setting evlist->mmap[i].fd is unsafe and perf_evlist__alloc_mmap() should bail out right after that. Signed-off-by: NWang Nan <wangnan0@huawei.com> Acked-by: NMasami Hiramatsu <mhiramat@kernel.org> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Fixes: d4c6fb36 ("perf evsel: Record fd into perf_mmap") Link: http://lkml.kernel.org/r/1464699975-230440-1-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Arnaldo Carvalho de Melo 提交于
Out of perf_evsel__intval(), that requires passing the variable name, that will then be searched in the list of tracepoint variables for the given evsel. In cases such as syscall file descriptor ("fd") tracking, this is wasteful, we need just to use perf_evsel__field() and cache the format_field. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-r6f89jx9j5nkx037d0naviqy@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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- 03 6月, 2016 13 次提交
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由 Andi Kleen 提交于
Now that we have topology_max_smt_threads() use it to detect the HT workarounds for older CPUs. Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1463703002-19686-6-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andi Kleen 提交于
Add topdown event declarations to Silvermont / Airmont. These cores do not support the full Top Down metrics, but an useful subset (FrontendBound, Retiring, Backend Bound/Bad Speculation). The perf stat tool automatically handles the missing events and combines the available metrics. Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1463703002-19686-5-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andi Kleen 提交于
Add declarations for the events needed for topdown to the Intel big core CPUs starting with Sandy Bridge. We need to report different values if HyperThreading is on or off. The only thing this patch does is to export some events in sysfs. topdown level 1 uses a set of abstracted metrics which are generic to out of order CPU cores (although some CPUs may not implement all of them): topdown-total-slots Available slots in the pipeline topdown-slots-issued Slots issued into the pipeline topdown-slots-retired Slots successfully retired topdown-fetch-bubbles Pipeline gaps in the frontend topdown-recovery-bubbles Pipeline gaps during recovery from misspeculation A slot is a single operation in the CPU pipe line. These metrics then allow to compute four useful metrics: FrontendBound, BackendBound, Retiring, BadSpeculation. The formulas to compute the metrics are generic, they only change based on the availability on the abstracted input values. The kernel declares the events supported by the current CPU and their scaling factors (such as the pipeline width) and perf stat then computes the formulas based on the available metrics. This is similar how existing perf metrics, such as TSC metrics or IPC, are implemented. This abstracts all CPU pipe line specific knowledge in the kernel driver, but still avoids the need for larger scale perf interface changes. For HyperThreading the any bit is needed to get accurate values when both threads are executing. This implies that the events can only be collected as root or with perf_event_paranoid=-1 for now. The basic scheme is based on the following paper: Yasin, A Top Down Method for Performance analysis and Counter architecture ISPASS14 (pdf available via google) Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1463703002-19686-4-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andi Kleen 提交于
Add a way to show different sysfs events attributes depending on HyperThreading is on or off. This is difficult to determine early at boot, so we just do it dynamically when the sysfs attribute is read. Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1463703002-19686-3-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Andi Kleen 提交于
For SMT specific workarounds it is useful to know if SMT is active on any online CPU in the system. This currently requires a loop over all online CPUs. Add a global variable that is updated with the maximum number of smt threads on any CPU on online/offline, and use it for topology_max_smt_threads() The single call is easier to use than a loop. Not exported to user space because user space already can use the existing sibling interfaces to find this out. Signed-off-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Cc: jolsa@kernel.org Link: http://lkml.kernel.org/r/1463703002-19686-2-git-send-email-andi@firstfloor.orgSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Vineet Gupta 提交于
This allows (with a previous change to the perf error return ABI) for calling out in userspace the exact reason for perf record failing when PMU doesn't support overflow interrupts. Note that this needs to be put ahead of existing precise_ip check as that gets hit otherwise for the sampling fail case as well. Signed-off-by: NVineet Gupta <vgupta@synopsys.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: <acme@redhat.com> Cc: <linux-snps-arc@lists.infradead.org> Cc: <vincent.weaver@maine.edu> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com> Link: http://lkml.kernel.org/r/1462786660-2900-2-git-send-email-vgupta@synopsys.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Vineet Gupta 提交于
Change the return code for sampling event not supported from -ENOTSUPP to -EOPNOTSUPP. This allows userspace to identify this case specifically, instead of printing the catch-all error message it did previously. Technically this is an ABI change, but we think we can get away with it. Old behavior: ------- | # perf record ls | Error: | The sys_perf_event_open() syscall returned with 524 (Unknown error 524) | for event (cycles:ppp). | /bin/dmesg may provide additional information. | No CONFIG_PERF_EVENTS=y kernel support configured? New behavior: ------- | # perf record ls | Error: | PMU Hardware doesn't support sampling/overflow-interrupts. Signed-off-by: NVineet Gupta <vgupta@synopsys.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: <acme@redhat.com> Cc: <linux-snps-arc@lists.infradead.org> Cc: <vincent.weaver@maine.edu> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Vineet Gupta <Vineet.Gupta1@synopsys.com> Link: http://lkml.kernel.org/r/1462786660-2900-3-git-send-email-vgupta@synopsys.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Kan Liang 提交于
Some platforms, e.g. Knights Landing, use a common PCI device ID for multiple instances of an uncore PMU device type. So it is impossible to locate the specific instances only by PCI device ID. The current code specially handles Knights Landing by arbitrarily pointing an instance to an unused uncore box. However, we still have no idea which uncore device is mapped to which box. Furthermore, there could be more platforms which use a common PCI device ID for uncore devices. We have to specially handle them one by one. This patch records full device information (slot, func, and device ID) in id_table[]. So the probe function can point the instance to a specific uncore box by checking the full device information. Tested-by: NLukasz Odzioba <lukasz.odzioba@intel.com> Signed-off-by: NKan Liang <kan.liang@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Acked-by: tglx@linutronix.de Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: bp@suse.de Cc: harish.chegondi@intel.com Cc: hubert.chrzaniuk@intel.com Cc: lawrence.f.meadows@intel.com Link: http://lkml.kernel.org/r/1463379504-39003-1-git-send-email-kan.liang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Lukasz Odzioba 提交于
Due to change in register definition we need to update OCR mask: MSR_OFFCORE_RESP0 reserved bits: 3,4,18,29,30,33,34, 8,11,14 MSR_OFFCORE_RESP1 reserved bits: 3,4,18,29,30,33,34, 38 Reported-by: NAndi Kleen <ak@linux.intel.com> Signed-off-by: NLukasz Odzioba <lukasz.odzioba@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: akpm@linux-foundation.org Cc: hpa@zytor.com Cc: kan.liang@intel.com Cc: lukasz.anaczkowski@intel.com Cc: zheng.z.yan@intel.com Link: http://lkml.kernel.org/r/1463433419-16893-1-git-send-email-lukasz.odzioba@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Lukasz Odzioba 提交于
Add the 'static' keyword to intel_bdw_event_constraints[], snb_events_attrs[], nhm_events_attrs[] and intel_skl_event_constraints arrays[], because they are only used locally. Signed-off-by: NLukasz Odzioba <lukasz.odzioba@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: akpm@linux-foundation.org Cc: hpa@zytor.com Cc: kan.liang@intel.com Cc: lukasz.anaczkowski@intel.com Cc: zheng.z.yan@intel.com Link: http://lkml.kernel.org/r/1463433378-16816-1-git-send-email-lukasz.odzioba@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Kan Liang 提交于
This patch fixes an issue which was introduced by commit: 91a612ee ("perf/core: Fix dynamic interrupt throttle") ... which commit unconditionally sets the perf_sample_allowed_ns value to !0. But that could trigger a bug in the following corner case: The user can disable the dynamic interrupt throttle mechanism by setting perf_cpu_time_max_percent to 0. Then they change perf_event_max_sample_rate. For this case, the mechanism will be enabled implicitly, because perf_sample_allowed_ns becomes !0 - which is not what we want. This patch only updates perf_sample_allowed_ns when the dynamic interrupt throttle mechanism is enabled. Signed-off-by: NKan Liang <kan.liang@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: acme@kernel.org Link: http://lkml.kernel.org/r/1462260366-3160-1-git-send-email-kan.liang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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由 Peter Zijlstra 提交于
perf/core: Rename the perf_event_aux*() APIs to perf_event_sb*(), to separate them from AUX ring-buffer records There are now two different things called AUX in perf, the infrastructure to deliver the mmap/comm/task records and the AUX part in the mmap buffer (with associated AUX_RECORD). Since the former is internal, rename it to side-band to reduce the confusion factor. No change in functionality. Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: linux-kernel@vger.kernel.org Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Kan Liang 提交于
The perf_event_aux() function iterates all PMUs and all events in their respective per-CPU contexts to find the events to deliver side-band records to. For example, the brk test case in lkp triggers many mmap() operations, which, if we're also running perf, results in many perf_event_aux() invocations. If we enable uncore PMU support (even when uncore events are not used), dozens of uncore PMUs will be iterated, which can significantly decrease brk_test's throughput. For example, the brk throughput: without uncore PMUs: 2647573 ops_per_sec with uncore PMUs: 1768444 ops_per_sec ... a 33% reduction. To get at the per-CPU events that need side-band records, this patch puts these events on a per-CPU list, this avoids iterating the PMUs and any events that do not need side-band records. Per task events are unchanged to avoid extra overhead on the context switch paths. Suggested-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Reported-by: NHuang, Ying <ying.huang@linux.intel.com> Signed-off-by: NKan Liang <kan.liang@intel.com> Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Link: http://lkml.kernel.org/r/1458757477-3781-1-git-send-email-kan.liang@intel.comSigned-off-by: NIngo Molnar <mingo@kernel.org>
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- 31 5月, 2016 4 次提交
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由 Ingo Molnar 提交于
Merge tag 'perf-core-for-mingo-20160530' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: User visible/kernel ABI changes: - Per event callchain limit: Recently we introduced a sysctl to tune the max-stack for all events for which callchains were requested: $ sysctl kernel.perf_event_max_stack kernel.perf_event_max_stack = 127 Now this patch introduces a way to configure this per event, i.e. this becomes possible: $ perf record -e sched:*/max-stack=2/ -e block:*/max-stack=10/ -a allowing finer tuning of how much buffer space callchains use. This uses an u16 from the reserved space at the end, leaving another u16 for future use. There has been interest in even finer tuning, namely to control the max stack for kernel and userspace callchains separately. Further discussion is needed, we may for instance use the remaining u16 for that and when it is present, assume that the sample_max_stack introduced in this patch applies for the kernel, and the u16 left is used for limiting the userspace callchain. (Arnaldo Carvalho de Melo) Infrastructure changes: - Adopt get_main_thread from db-export.c (Andi Kleen) - More prep work for backward ring buffer support (Wang Nan) - Prep work for supporting SDT (Statically Defined Tracing) tracepoints (Masami Hiramatsu) - Add arch/*/include/generated/ to .gitignore (Taeung Song) Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Masami Hiramatsu 提交于
Use path/to/bin/buildid/elf instead of path/to/bin/buildid to store corresponding elf binary. This also stores vdso in buildid/vdso, kallsyms in buildid/kallsyms. Note that the existing caches are not updated until user adds or updates the cache. Anyway, if there is the old style build-id cache it falls back to use it. (IOW, it is backward compatible) Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org> Signed-off-by: NMasami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: NNamhyung Kim <namhyung@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20160528151537.16098.85815.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Masami Hiramatsu 提交于
Cleanup the code flow of dso__find_kallsyms() to remove redundant checking code and add some comment for readability. Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org> Acked-by: NNamhyung Kim <namhyung@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20160528151522.16098.43446.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Masami Hiramatsu 提交于
Introduce filename__readable to check readability by opening the file directly. Since the access(R_OK) just checks the readability based on real UID/GID, it is ignored that the effective UID/GID and capabilities for some special file (e.g. /proc/kcore). filename__readable() directly opens given file with O_RDONLY so that the kernel checks it by effective UID/GID and capabilities. Signed-off-by: NMasami Hiramatsu <mhiramat@kernel.org> Acked-by: NNamhyung Kim <namhyung@kernel.org> Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: Hemant Kumar <hemant@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/20160528151513.16098.97576.stgit@devboxSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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- 30 5月, 2016 10 次提交
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由 Taeung Song 提交于
Commit 1b700c99 ("perf tools: Build syscall table .c header from kernel's syscall_64.tbl") automatically generates per-arch syscall table arrays, e.g.: arch/x86/include/generated/asm/syscalls_64.c So add this directory to .gitignore Signed-off-by: NTaeung Song <treeze.taeung@gmail.com> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Wang Nan <wangnan0@huawei.com> Fixes: 1b700c99 ("perf tools: Build syscall table .c header from kernel's syscall_64.tbl") Link: http://lkml.kernel.org/r/1464343274-19403-1-git-send-email-treeze.taeung@gmail.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Wang Nan 提交于
Before this patch there's no way to pass arguments to fdarray__filter's call back function. This improvement will be used by 'perf record' to support unmapping ring buffer for both main evlist and overwrite evlist. Without this patch there's no way to track overwrite evlist from 'struct fdarray'. Signed-off-by: NWang Nan <wangnan0@huawei.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1464183898-174512-10-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Wang Nan 提交于
Now we have evlist->backward to indicate the mmap direction. Make perf_evlist__mmap_read() choose right direction automatically. Signed-off-by: NWang Nan <wangnan0@huawei.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1464183898-174512-3-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Wang Nan 提交于
evlist->mmap[i]->refcnt could be 0 if an evlist has no evsel or if all evsels don't match the evlist during mmap. For example, when all evsels are overwritable but the evlist itself is normal. To avoid crashing, perf should check 'base' pointer before checking refcnt, and raise bug only when base is not NULL. Signed-off-by: NWang Nan <wangnan0@huawei.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1464183898-174512-2-git-send-email-wangnan0@huawei.com [ Renamed 'mmap' variable, it is reserved in old distros such as Ubuntu 12.04, breaking the build ] Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Wang Nan 提交于
There's no need to receive events from overwritable ring buffer. Instead, perf should make them run in background until some external event of interest takes place. This patch makes ignores normal events from overwrite evlists. Overwritable events must be mapped readonly and backward, so if evlist and evsel doesn't match (evsel->overwrite is true but either evlist is read/write or evlist is not backward, and vice versa), skip mapping it. Signed-off-by: NWang Nan <wangnan0@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1464056944-166978-3-git-send-email-wangnan0@huawei.comSigned-off-by: NHe Kuang <hekuang@huawei.com> [ Split from a larger patch ] Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Wang Nan 提交于
It is possible that all events in an evlist are overwritable. perf_event__synth_time_conv() should not crash in this case. record__pick_pc() is used to check avaliability. Signed-off-by: NWang Nan <wangnan0@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1464056944-166978-3-git-send-email-wangnan0@huawei.comSigned-off-by: NHe Kuang <hekuang@huawei.com> [ Split from a larger patch ] Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Arnaldo Carvalho de Melo 提交于
The tooling counterpart, now it is possible to do: # perf record -e sched:sched_switch/max-stack=10/ -e cycles/call-graph=dwarf,max-stack=4/ -e cpu-cycles/call-graph=dwarf,max-stack=1024/ usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.052 MB perf.data (5 samples) ] # perf evlist -v sched:sched_switch: type: 2, size: 112, config: 0x110, { sample_period, sample_freq }: 1, sample_type: IP|TID|TIME|CALLCHAIN|CPU|PERIOD|RAW|IDENTIFIER, read_format: ID, disabled: 1, inherit: 1, mmap: 1, comm: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1, sample_max_stack: 10 cycles/call-graph=dwarf,max-stack=4/: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CALLCHAIN|PERIOD|REGS_USER|STACK_USER|IDENTIFIER, read_format: ID, disabled: 1, inherit: 1, freq: 1, enable_on_exec: 1, sample_id_all: 1, exclude_guest: 1, exclude_callchain_user: 1, sample_regs_user: 0xff0fff, sample_stack_user: 8192, sample_max_stack: 4 cpu-cycles/call-graph=dwarf,max-stack=1024/: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|CALLCHAIN|PERIOD|REGS_USER|STACK_USER|IDENTIFIER, read_format: ID, disabled: 1, inherit: 1, freq: 1, enable_on_exec: 1, sample_id_all: 1, exclude_guest: 1, exclude_callchain_user: 1, sample_regs_user: 0xff0fff, sample_stack_user: 8192, sample_max_stack: 1024 # Tip: use 'perf evlist --trace-fields' to show fields for tracepoint events Using just /max-stack=N/ means /call-graph=fp,max-stack=N/, that should be further configurable by means of some .perfconfig knob. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Wang Nan <wangnan0@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/n/tip-kolmn1yo40p7jhswxwrc7rrd@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Arnaldo Carvalho de Melo 提交于
Additionally to being able to control the system wide maximum depth via /proc/sys/kernel/perf_event_max_stack, now we are able to ask for different depths per event, using perf_event_attr.sample_max_stack for that. This uses an u16 hole at the end of perf_event_attr, that, when perf_event_attr.sample_type has the PERF_SAMPLE_CALLCHAIN, if sample_max_stack is zero, means use perf_event_max_stack, otherwise it'll be bounds checked under callchain_mutex. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Brendan Gregg <brendan.d.gregg@gmail.com> Cc: David Ahern <dsahern@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: He Kuang <hekuang@huawei.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Milian Wolff <milian.wolff@kdab.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Cc: Wang Nan <wangnan0@huawei.com> Cc: Zefan Li <lizefan@huawei.com> Link: http://lkml.kernel.org/n/tip-kolmn1yo40p7jhswxwrc7rrd@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Andi Kleen 提交于
Move the get_main_thread function from db-export.c to thread.c so that it can be used elsewhere. Signed-off-by: NAndi Kleen <ak@linux.intel.com> Cc: Jiri Olsa <jolsa@kernel.org> Link: http://lkml.kernel.org/r/1464051145-19968-2-git-send-email-andi@firstfloor.org [ Removed leftover bits from db-export.h ] Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Ingo Molnar 提交于
Merge tag 'perf-urgent-for-mingo-20160527' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fixes from Arnaldo Carvalho de Melo: - Fix kptr_restrict=2 related 'perf record' segfault (Wang Nan) - Fix CTF/libbabeltrace handling of chinese COMM strings (Wang Nan) Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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- 27 5月, 2016 3 次提交
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由 Wang Nan 提交于
We observed some crazy apps on Android set their comm to unprintable string. For example: # cat /proc/10607/task/*/comm tencent.qqmusic ... Binder_2 日志输出线 <-- Chinese word 'log output thread' WifiManager ... 'perf data convert' fails to convert perf.data with such string to CTF format. For example: # cat << EOF > ./badguy.c #include <sys/prctl.h> int main(int argc, char *argv[]) { prctl(PR_SET_NAME, "\xe6\x97\xa5\xe5\xbf\x97\xe8\xbe\x93\xe5\x87\xba\xe7\xba\xbf"); while(1) sleep(1); return 0; } EOF # gcc ./badguy.c # perf record -e sched:* ./a.out # perf data convert --to-ctf ./bad.ctf CTF stream 4 flush failed [ perf data convert: Converted 'perf.data' into CTF data './bad.ctf' ] [ perf data convert: Converted and wrote 0.008 MB (78 samples) ] # babeltrace ./bad.ctf/ [error] Packet size (18446744073709551615 bits) is larger than remaining file size (262144 bits). [error] Stream index creation error. [error] Open file stream error. [warning] [Context] Cannot open_trace of format ctf at path ./bad.ctf. [warning] [Context] cannot open trace "./bad.ctf" from ./bad.ctf/ for reading. [error] Cannot open any trace for reading. [error] opening trace "./bad.ctf/" for reading. [error] none of the specified trace paths could be opened. This patch converts unprintable characters to hexadecimal word. After applying this patch the above test works correctly: # ~/perf data convert --to-ctf ./good.ctf [ perf data convert: Converted 'perf.data' into CTF data './good.ctf' ] [ perf data convert: Converted and wrote 0.008 MB (78 samples) ] # babeltrace ./good.ctf .. [23:14:35.491665268] (+0.000001100) sched:sched_wakeup: { cpu_id = 4 }, { perf_ip = 0xFFFFFFFF810AEF33, perf_tid = 0, perf_pid = 0, perf_id = 5123, perf_period = 1, common_type = 270, common_flags = 45, common_preempt_count = 4, common_pid = 0, comm = "\xe6\x97\xa5\xe5\xbf\x97\xe8\xbe\x93\xe5\x87\xba\xe7\xba\xbf", pid = 1057, prio = 120, success = 1, target_cpu = 4 } [23:14:35.491666230] (+0.000000962) sched:sched_wakeup: { cpu_id = 4 }, { perf_ip = 0xFFFFFFFF810AEF33, perf_tid = 0, perf_pid = 0, perf_id = 5122, perf_period = 1, common_type = 270, common_flags = 45, common_preempt_count = 4, common_pid = 0, comm = "\xe6\x97\xa5\xe5\xbf\x97\xe8\xbe\x93\xe5\x87\xba\xe7\xba\xbf", pid = 1057, prio = 120, success = 1, target_cpu = 4 } .. Committer note: To build perf with libabeltrace, use: $ mkdir -p /tmp/build/perf $ make LIBBABELTRACE=1 LIBBABELTRACE_DIR=/usr/local O=/tmp/build/perf -C tools/perf install-bin Or equivalent (no O=, fixup LIBBABELTRACE_DIR, etc). Signed-off-by: NWang Nan <wangnan0@huawei.com> Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1464348951-179595-1-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Wang Nan 提交于
Before this patch, a simple 'perf record' could fail if kptr_restrict is set to 1 (for normal user) or 2 (for root): # perf record ls WARNING: Kernel address maps (/proc/{kallsyms,modules}) are restricted, check /proc/sys/kernel/kptr_restrict. Samples in kernel functions may not be resolved if a suitable vmlinux file is not found in the buildid cache or in the vmlinux path. Samples in kernel modules won't be resolved at all. If some relocation was applied (e.g. kexec) symbols may be misresolved even with a suitable vmlinux or kallsyms file. Segmentation fault (core dumped) This patch skips perf_event__synthesize_kernel_mmap() when kptr is not available. Signed-off-by: NWang Nan <wangnan0@huawei.com> Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com> Fixes: 45e90056 ("perf machine: Do not bail out if not managing to read ref reloc symbol") Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1464081688-167940-2-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Wang Nan 提交于
If kptr_restrict is set to 2, even root is not allowed to see pointers. This patch checks kptr_restrict even if euid == 0. For root, report error if kptr_restrict is 2. Signed-off-by: NWang Nan <wangnan0@huawei.com> Tested-by: NArnaldo Carvalho de Melo <acme@redhat.com> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1464081688-167940-1-git-send-email-wangnan0@huawei.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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- 25 5月, 2016 1 次提交
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由 Vincent Stehlé 提交于
On rapl cleanup path, kfree() is given by mistake the address of the pointer of the structure to free (rapl_pmus->pmus + i). Pass the pointer instead (rapl_pmus->pmus[i]). Fixes: 9de8d686 "perf/x86/intel/rapl: Convert it to a per package facility" Signed-off-by: NVincent Stehlé <vincent.stehle@intel.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: stable@vger.kernel.org Link: http://lkml.kernel.org/r/1464101629-14905-1-git-send-email-vincent.stehle@intel.comSigned-off-by: NThomas Gleixner <tglx@linutronix.de>
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- 24 5月, 2016 3 次提交
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由 Ingo Molnar 提交于
Merge tag 'perf-core-for-mingo-20160523' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/core improvements from Arnaldo Carvalho de Melo: User visible changes: - Add "srcline_from" and "srcline_to" branch sort keys to 'perf top' and 'perf report' (Andi Kleen) Infrastructure changes: - Make 'perf trace' auto-attach fd->name and ptr->name beautifiers based on the name of syscall arguments, this way new syscalls that have 'const char * (path,pathname,filename)' will use the fd->name beautifier (vfs_getname perf probe, if in place) and the 'fd->name' (vfs_getname or via /proc/PID/fd/) (Arnaldo Carvalho de Melo) - Infrastructure to read from a ring buffer in backward write mode (Wang Nan) Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: NIngo Molnar <mingo@kernel.org>
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由 Wang Nan 提交于
Introduce rb_find_range() to find start and end position from a backward ring buffer. Signed-off-by: NWang Nan <wangnan0@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1463987628-163563-5-git-send-email-wangnan0@huawei.comSigned-off-by: NHe Kuang <hekuang@huawei.com> Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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由 Wang Nan 提交于
record__mmap_read() writes data from ring buffer into perf.data. 'head' is maintained by the kernel, points to the last written record. 'old' is maintained by perf, points to the record read in previous round. record__mmap_read() saves data from 'old' to 'head' to perf.data. The names of these variables are not very intutive. In addition, when dealing with backward writing ring buffer, the md->prev pointer should point to 'head' instead of the last byte it got. Add 'start' and 'end' pointer to make code clear and set md->prev to 'head' instead of the moved 'old' pointer. This patch doesn't change behavior since: buf = &data[old & md->mask]; size = head - old; old += size; <--- Here, old == head Signed-off-by: NWang Nan <wangnan0@huawei.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Zefan Li <lizefan@huawei.com> Cc: pi3orama@163.com Link: http://lkml.kernel.org/r/1463987628-163563-4-git-send-email-wangnan0@huawei.comSigned-off-by: NHe Kuang <hekuang@huawei.com> Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>
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