kernel/linux.git/tools/perf/util, branch v4.6.4

perf evsel: Handle EACCESS + perf_event_paranoid=2 in fallback()

2016-05-12T19:13:16+00:00

Now with the default for the kernel.perf_event_paranoid sysctl being 2 [1] we need to fall back to :u, i.e. to set perf_event_attr.exclude_kernel to 1. Before: [acme@jouet linux]$ perf record usleep 1 Error: You may not have permission to collect stats. Consider tweaking /proc/sys/kernel/perf_event_paranoid, which controls use of the performance events system by unprivileged users (without CAP_SYS_ADMIN). The current value is 2: -1: Allow use of (almost) all events by all users >= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK >= 1: Disallow CPU event access by users without CAP_SYS_ADMIN >= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN [acme@jouet linux]$ After: [acme@jouet linux]$ perf record usleep 1 [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.016 MB perf.data (7 samples) ] [acme@jouet linux]$ perf evlist cycles:u [acme@jouet linux]$ perf evlist -v cycles:u: size: 112, { sample_period, sample_freq }: 4000, sample_type: IP|TID|TIME|PERIOD, disabled: 1, inherit: 1, exclude_kernel: 1, mmap: 1, comm: 1, freq: 1, enable_on_exec: 1, task: 1, sample_id_all: 1, exclude_guest: 1, mmap2: 1, comm_exec: 1 [acme@jouet linux]$ And if the user turns on verbose mode, an explanation will appear: [acme@jouet linux]$ perf record -v usleep 1 Warning: kernel.perf_event_paranoid=2, trying to fall back to excluding kernel samples mmap size 528384B [ perf record: Woken up 1 times to write data ] Looking at the vmlinux_path (8 entries long) Using /lib/modules/4.6.0-rc7+/build/vmlinux for symbols [ perf record: Captured and wrote 0.016 MB perf.data (7 samples) ] [acme@jouet linux]$ [1] 0161028b7c8a ("perf/core: Change the default paranoia level to 2") Reported-by: Ingo Molnar Cc: Adrian Hunter Cc: Andy Lutomirski Cc: David Ahern Cc: Jiri Olsa Cc: Kees Cook Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-b20jmx4dxt5hpaa9t2rroi0o@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Improve EPERM error handling in open_strerror()

2016-05-12T18:44:55+00:00

We were showing a hardcoded default value for the kernel.perf_event_paranoid sysctl, now that it became more paranoid (1 -> 2 [1]), this would need to be updated, instead show the current value: [acme@jouet linux]$ perf record ls Error: You may not have permission to collect stats. Consider tweaking /proc/sys/kernel/perf_event_paranoid, which controls use of the performance events system by unprivileged users (without CAP_SYS_ADMIN). The current value is 2: -1: Allow use of (almost) all events by all users >= 0: Disallow raw tracepoint access by users without CAP_IOC_LOCK >= 1: Disallow CPU event access by users without CAP_SYS_ADMIN >= 2: Disallow kernel profiling by users without CAP_SYS_ADMIN [acme@jouet linux]$ [1] 0161028b7c8a ("perf/core: Change the default paranoia level to 2") Reported-by: Ingo Molnar Cc: Adrian Hunter Cc: Andy Lutomirski Cc: David Ahern Cc: Jiri Olsa Cc: Kees Cook Cc: Linus Torvalds Cc: Masami Hiramatsu Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-0gc4rdpg8d025r5not8s8028@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf probe: Check if dwarf_getlocations() is available

2016-05-12T14:26:59+00:00

If not, tell the user that: config/Makefile:273: Old libdw.h, finding variables at given 'perf probe' point will not work, install elfutils-devel/libdw-dev >= 0.157 And return -ENOTSUPP in die_get_var_range(), failing features that need it, like the one pointed out above. This fixes the build on older systems, such as Ubuntu 12.04.5. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Vinson Lee Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-9l7luqkq4gfnx7vrklkq4obs@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use readdir() instead of deprecated readdir_r()

2016-05-12T14:26:58+00:00

The readdir() function is thread safe as long as just one thread uses a DIR, which is the case when parsing tracepoint event definitions, to avoid breaking the build with glibc-2.23.90 (upcoming 2.24), use it instead of readdir_r(). See: http://man7.org/linux/man-pages/man3/readdir.3.html "However, in modern implementations (including the glibc implementation), concurrent calls to readdir() that specify different directory streams are thread-safe. In cases where multiple threads must read from the same directory stream, using readdir() with external synchronization is still preferable to the use of the deprecated readdir_r(3) function." Noticed while building on a Fedora Rawhide docker container. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-wddn49r6bz6wq4ee3dxbl7lo@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf thread_map: Use readdir() instead of deprecated readdir_r()

2016-05-12T14:26:58+00:00

The readdir() function is thread safe as long as just one thread uses a DIR, which is the case in thread_map, so, to avoid breaking the build with glibc-2.23.90 (upcoming 2.24), use it instead of readdir_r(). See: http://man7.org/linux/man-pages/man3/readdir.3.html "However, in modern implementations (including the glibc implementation), concurrent calls to readdir() that specify different directory streams are thread-safe. In cases where multiple threads must read from the same directory stream, using readdir() with external synchronization is still preferable to the use of the deprecated readdir_r(3) function." Noticed while building on a Fedora Rawhide docker container. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-del8h2a0f40z75j4r42l96l0@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use readdir() instead of deprecated readdir_r()

2016-05-12T13:22:54+00:00

The readdir() function is thread safe as long as just one thread uses a DIR, which is the case when synthesizing events for pre-existing threads by traversing /proc, so, to avoid breaking the build with glibc-2.23.90 (upcoming 2.24), use it instead of readdir_r(). See: http://man7.org/linux/man-pages/man3/readdir.3.html "However, in modern implementations (including the glibc implementation), concurrent calls to readdir() that specify different directory streams are thread-safe. In cases where multiple threads must read from the same directory stream, using readdir() with external synchronization is still preferable to the use of the deprecated readdir_r(3) function." Noticed while building on a Fedora Rawhide docker container. CC /tmp/build/perf/util/event.o util/event.c: In function '__event__synthesize_thread': util/event.c:466:2: error: 'readdir_r' is deprecated [-Werror=deprecated-declarations] while (!readdir_r(tasks, &dirent, &next) && next) { ^~~~~ In file included from /usr/include/features.h:368:0, from /usr/include/stdint.h:25, from /usr/lib/gcc/x86_64-redhat-linux/6.0.0/include/stdint.h:9, from /git/linux/tools/include/linux/types.h:6, from util/event.c:1: /usr/include/dirent.h:189:12: note: declared here Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-i1vj7nyjp2p750rirxgrfd3c@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf diff: Fix duplicated output column

2016-05-11T14:55:32+00:00

The commit b97511c5bc94 ("perf tools: Add overhead/overhead_children keys defaults via string") moved initialization of column headers but it missed to check the sort__mode. As 'perf diff' doesn't call perf_hpp__init(), the setup_overhead() also should not be called. Before: # Baseline Delta Children Overhead Shared Object Symbol # ........ ....... ........ ........ ................... ....................... # 28.48% -28.47% 28.48% 28.48% [kernel.vmlinux ] [k] intel_idle 11.51% -11.47% 11.51% 11.51% libxul.so [.] 0x0000000001a360f7 3.49% -3.49% 3.49% 3.49% [kernel.vmlinux] [k] generic_exec_single 2.91% -2.89% 2.91% 2.91% libdbus-1.so.3.8.11 [.] 0x000000000000cdc2 2.86% -2.85% 2.86% 2.86% libxcb.so.1.1.0 [.] 0x000000000000c890 2.44% -2.39% 2.44% 2.44% [kernel.vmlinux] [k] perf_event_aux_ctx After: # Baseline Delta Shared Object Symbol # ........ ....... ................... ....................... # 28.48% -28.47% [kernel.vmlinux] [k] intel_idle 11.51% -11.47% libxul.so [.] 0x0000000001a360f7 3.49% -3.49% [kernel.vmlinux] [k] generic_exec_single 2.91% -2.89% libdbus-1.so.3.8.11 [.] 0x000000000000cdc2 2.86% -2.85% libxcb.so.1.1.0 [.] 0x000000000000c890 2.44% -2.39% [kernel.vmlinux] [k] perf_event_aux_ctx Signed-off-by: Namhyung Kim Signed-off-by: Arnaldo Carvalho de Melo Acked-by: Jiri Olsa Cc: # 4.5+ Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Fixes: b97511c5bc94 ("perf tools: Add overhead/overhead_children keys defaults via string") Link: http://lkml.kernel.org/r/1462890384-12486-2-git-send-email-acme@kernel.org Signed-off-by: Ingo Molnar

Merge tag 'perf-urgent-for-mingo-20160418' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent

2016-04-19T06:41:59+00:00

Pull a perf/urgent fix from Arnaldo Carvalho de Melo: - Fix segfault tracing transactions in Intel PT (Adrian Hunter) Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Ingo Molnar

perf intel-pt: Fix segfault tracing transactions

2016-04-18T14:00:56+00:00

Tracing a workload that uses transactions gave a seg fault as follows: perf record -e intel_pt// workload perf report Program received signal SIGSEGV, Segmentation fault. 0x000000000054b58c in intel_pt_reset_last_branch_rb (ptq=0x1a36110) at util/intel-pt.c:929 929 ptq->last_branch_rb->nr = 0; (gdb) p ptq->last_branch_rb $1 = (struct branch_stack *) 0x0 (gdb) up 1148 intel_pt_reset_last_branch_rb(ptq); (gdb) l 1143 if (ret) 1144 pr_err("Intel Processor Trace: failed to deliver transaction event 1145 ret); 1146 1147 if (pt->synth_opts.callchain) 1148 intel_pt_reset_last_branch_rb(ptq); 1149 1150 return ret; 1151 } 1152 (gdb) p pt->synth_opts.callchain $2 = true (gdb) (gdb) bt #0 0x000000000054b58c in intel_pt_reset_last_branch_rb (ptq=0x1a36110) #1 0x000000000054c1e0 in intel_pt_synth_transaction_sample (ptq=0x1a36110) #2 0x000000000054c5b2 in intel_pt_sample (ptq=0x1a36110) Caused by checking the 'callchain' flag when it should have been the 'last_branch' flag. Fix that. Reported-by: Andi Kleen Signed-off-by: Adrian Hunter Cc: Jiri Olsa Cc: stable@vger.kernel.org # v4.4+ Fixes: f14445ee72c5 ("perf intel-pt: Support generating branch stack") Link: http://lkml.kernel.org/r/1460977068-11566-1-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-04-03T12:22:12+00:00

Pull perf fixes from Ingo Molnar: "Misc kernel side fixes: - fix event leak - fix AMD PMU driver bug - fix core event handling bug - fix build bug on certain randconfigs Plus misc tooling fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/amd/ibs: Fix pmu::stop() nesting perf/core: Don't leak event in the syscall error path perf/core: Fix time tracking bug with multiplexing perf jit: genelf makes assumptions about endian perf hists: Fix determination of a callchain node's childlessness perf tools: Add missing initialization of perf_sample.cpumode in synthesized samples perf tools: Fix build break on powerpc perf/x86: Move events_sysfs_show() outside CPU_SUP_INTEL perf bench: Fix detached tarball building due to missing 'perf bench memcpy' headers perf tests: Fix tarpkg build test error output redirection