kernel/tools/perf/util/evsel.c, branch linux-4.15.y

perf evsel: Enable ignore_missing_thread for pid option

2018-04-12T10:31:02Z

[ Upstream commit ca8000684ec4e66f965e1f9547a3c6cb834154ca ] While monitoring a multithread process with pid option, perf sometimes may return sys_perf_event_open failure with 3(No such process) if any of the process's threads die before we open the event. However, we want perf continue monitoring the remaining threads and do not exit with error. Here, the patch enables perf_evsel::ignore_missing_thread for -p option to ignore complete failure if any of threads die before we open the event. But it may still return sys_perf_event_open failure with 22(Invalid) if we monitors several event groups. sys_perf_event_open: pid 28960 cpu 40 group_fd 118202 flags 0x8 sys_perf_event_open: pid 28961 cpu 40 group_fd 118203 flags 0x8 WARNING: Ignored open failure for pid 28962 sys_perf_event_open: pid 28962 cpu 40 group_fd [118203] flags 0x8 sys_perf_event_open failed, error -22 That is because when we ignore a missing thread, we change the thread_idx without dealing with its fds, FD(evsel, cpu, thread). Then get_group_fd() may return a wrong group_fd for the next thread and sys_perf_event_open() return with 22. sys_perf_event_open(){ ... if (group_fd != -1) perf_fget_light()//to get corresponding group_leader by group_fd ... if (group_leader) if (group_leader->ctx->task != ctx->task)//should on the same task goto err_context ... } This patch also fixes this bug by introducing perf_evsel__remove_fd() and update_fds to allow removing fds for the missing thread. Changes since v1: - Change group_fd__remove() into a more genetic way without changing code logic - Remove redundant condition Changes since v2: - Use a proper function name and add some comment. - Multiline comment style fixes. Committer testing: Before this patch the recently added 'perf stat --per-thread' for system wide counting would race while enumerating all threads using /proc: [root@jouet ~]# perf stat --per-thread failed to parse CPUs map: No such file or directory Usage: perf stat [] [] -C, --cpu list of cpus to monitor in system-wide -a, --all-cpus system-wide collection from all CPUs [root@jouet ~]# perf stat --per-thread failed to parse CPUs map: No such file or directory Usage: perf stat [] [] -C, --cpu list of cpus to monitor in system-wide -a, --all-cpus system-wide collection from all CPUs [root@jouet ~]# When, say, the kernel was being built, so lots of shortlived threads, after this patch this doesn't happen. Signed-off-by: Mengting Zhang Tested-by: Arnaldo Carvalho de Melo Acked-by: Jiri Olsa Cc: Cheng Jian Cc: Li Bin Cc: Wang Nan Link: http://lkml.kernel.org/r/1513148513-6974-1-git-send-email-zhangmengting@huawei.com [ Remove one use 'evlist' alias variable ] Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

perf evsel: Fix swap for samples with raw data

2018-04-12T10:31:02Z

[ Upstream commit f9d8adb345d7adbb2d3431eea73beb89c8d6d612 ] When we detect a different endianity we swap event before processing. It's tricky for samples because we have no idea what's inside. We treat it as an array of u64s, swap them and later on we swap back parts which are different. We mangle this way also the tracepoint raw data, which ends up in report showing wrong data: 1.95% comm=Q^B pid=29285 prio=16777216 target_cpu=000 1.67% comm=l^B pid=0 prio=16777216 target_cpu=000 Luckily the traceevent library handles the endianity by itself (thank you Steven!), so we can pass the RAW data directly in the other endianity. 2.51% comm=beah-rhts-task pid=1175 prio=120 target_cpu=002 2.23% comm=kworker/0:0 pid=11566 prio=120 target_cpu=000 The fix is basically to swap back the raw data if different endianity is detected. Signed-off-by: Jiri Olsa Cc: David Ahern Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Steven Rostedt Link: http://lkml.kernel.org/r/20171129184346.3656-1-jolsa@kernel.org [ Add util/memswap.c to python-ext-sources to link missing mem_bswap_64() ] Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

perf evsel: Fix up leftover perf_evsel_stat usage via evsel->priv

2017-11-28T17:20:32Z

I forgot one conversion, which got noticed by Thomas when running: $ perf stat -e '{cpu-clock,instructions}' kill kill: not enough arguments Segmentation fault (core dumped) $ Fix it, those stats are in evsel->stats, not anymore in evsel->priv. Reported-by: Thomas-Mich Richter Tested-by: Thomas-Mich Richter Cc: Adrian Hunter Cc: Andi Kleen Cc: David Ahern Cc: Hendrik Brueckner Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Fixes: e669e833da8d ("perf evsel: Restore evsel->priv as a tool private area") Link: http://lkml.kernel.org/r/20171109150046.GN4333@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf record: Fix -c/-F options for cpu event aliases

2017-11-28T17:19:39Z

The Intel PMU event aliases have a implicit period= specifier to set the default period. Unfortunately this breaks overriding these periods with -c or -F, because the alias terms look like they are user specified to the internal parser, and user specified event qualifiers override the command line options. Track that they are coming from aliases by adding a "weak" state to the term. Any weak terms don't override command line options. I only did it for -c/-F for now, I think that's the only case that's broken currently. Before: $ perf record -c 1000 -vv -e uops_issued.any ... { sample_period, sample_freq } 2000003 After: $ perf record -c 1000 -vv -e uops_issued.any ... { sample_period, sample_freq } 1000 Signed-off-by: Andi Kleen Acked-by: Jiri Olsa Link: http://lkml.kernel.org/r/20171020202755.21410-2-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo

Merge remote-tracking branch 'tip/perf/urgent' into perf/core, to pick up fixes

2017-10-02T16:58:12Z

Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Fix attr.exclude_kernel setting for default cycles:p

2017-09-25T13:39:45Z

Yet another fix for probing the max attr.precise_ip setting: it is not enough settting attr.exclude_kernel for !root users, as they _can_ profile the kernel if the kernel.perf_event_paranoid sysctl is set to -1, so check that as well. Testing it: As non root: $ sysctl kernel.perf_event_paranoid kernel.perf_event_paranoid = 2 $ perf record sleep 1 $ perf evlist -v cycles:uppp: ..., exclude_kernel: 1, ... precise_ip: 3, ... Now as non-root, but with kernel.perf_event_paranoid set set to the most permissive value, -1: $ sysctl kernel.perf_event_paranoid kernel.perf_event_paranoid = -1 $ perf record sleep 1 $ perf evlist -v cycles:ppp: ..., exclude_kernel: 0, ... precise_ip: 3, ... $ I.e. non-root, default kernel.perf_event_paranoid: :uppp modifier = not allowed to sample the kernel, non-root, most permissible kernel.perf_event_paranoid: :ppp = allowed to sample the kernel. In both cases, use the highest available precision: attr.precise_ip = 3. Reported-and-Tested-by: Ingo Molnar Cc: Adrian Hunter Cc: Andy Lutomirski Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Fixes: d37a36979077 ("perf evsel: Fix attr.exclude_kernel setting for default cycles:p") Link: http://lkml.kernel.org/n/tip-nj2qkf75xsd6pw6hhjzfqqdx@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf record: Support direct --user-regs arguments

2017-09-13T12:49:14Z

USER_REGS can currently only collected implicitely with call graph recording. Sometimes it is useful to see them separately, and filter them. Add a new --user-regs option to record that is similar to --intr-regs, but acts on user regs. Signed-off-by: Andi Kleen Cc: Jiri Olsa Link: http://lkml.kernel.org/r/20170905170029.19722-1-andi@firstfloor.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Support new sample type for physical address

2017-09-01T17:46:00Z

Support new sample type PERF_SAMPLE_PHYS_ADDR for physical address. Add new option --phys-data to record sample physical address. Signed-off-by: Kan Liang Tested-by: Jiri Olsa Acked-by: Stephane Eranian Cc: Andi Kleen Cc: Madhavan Srinivasan Cc: Peter Zijlstra Cc: Thomas Gleixner Link: http://lkml.kernel.org/r/1504026672-7304-2-git-send-email-kan.liang@intel.com [ Added missing printing in evsel.c patch sent by Jiri Olsa ] Signed-off-by: Arnaldo Carvalho de Melo

perf record: Set read_format for inherit_stat

2017-08-28T14:05:10Z

Set read_format for what we expect to get from read event generated by perf_event_attr::inherit_stat. Signed-off-by: Jiri Olsa Cc: Alexander Shishkin Cc: Andi Kleen Cc: David Ahern Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/20170824162737.7813-5-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf: Fix documentation for sysctls perf_event_paranoid and perf_event_mlock_kb

2017-08-22T16:24:54Z

Fix misprint CAP_IOC_LOCK -> CAP_IPC_LOCK. This capability have nothing to do with raw tracepoints. This part is about bypassing mlock limits. Sysctl kernel.perf_event_paranoid = -1 allows raw and ftrace function tracepoints without CAP_SYS_ADMIN. Signed-off-by: Konstantin Khlebnikov Cc: Alexander Shishkin Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/150322916080.129746.11285255474738558340.stgit@buzz Signed-off-by: Arnaldo Carvalho de Melo