1. 05 Aug, 2015 6 commits
    • Kan Liang's avatar
      perf tools: Per-event time support · 32067712
      Kan Liang authored
      This patchkit adds the ability to turn off time stamps per event.
      
      One usaful case for partial time is to work with per-event callgraph to
      enable "PEBS threshold > 1" (https://lkml.org/lkml/2015/5/10/196), which
      can significantly reduce the sampling overhead.
      
      The event samples with time stamps off will not be ordered.
      Signed-off-by: default avatarKan Liang <kan.liang@intel.com>
      Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
      Cc: Andi Kleen <ak@linux.intel.com>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Link: http://lkml.kernel.org/r/1438677022-34296-2-git-send-email-kan.liang@intel.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      32067712
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Use vfs_getname syscall arg beautifier in more syscalls · 34221118
      Arnaldo Carvalho de Melo authored
      Those were covered and tested in this cset:
      
       access, chdir, chmod, chown, chroot, creat, getxattr,
       inotify_add_watch, lchown, lgetxattr, listxattr,
       lsetxattr, mkdir, mkdirat, mknod, rmdir, faccessat,
       newfstatat, openat, readlink, readlinkat, removexattr,
       setxattr, statfs, swapon, swapoff, truncate, unlinkat,
       utime, utimes, utimensat.
      
      E.g.:
      
        # trace -e statfs,access,mkdir mkdir /tmp/bla
         0.285 (0.020 ms): mkdir/2799 access(filename: /etc/ld.so.preload, mode: R         ) = -1 ENOENT No such file or directory
         1.070 (0.032 ms): mkdir/2799 statfs(pathname: /sys/fs/selinux, buf: 0x7ffeafbdc930) = 0
         1.087 (0.013 ms): mkdir/2799 statfs(pathname: /sys/fs/selinux, buf: 0x7ffeafbdc820) = 0
         1.189 (0.014 ms): mkdir/2799 access(filename: /etc/selinux/config                 ) = 0
         1.905 (0.610 ms): mkdir/2799 mkdir(pathname: /tmp/bla, mode: 511                  ) = 0
        #
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Milian Wolff <mail@milianw.de>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Link: http://lkml.kernel.org/n/tip-wbqtnlktquun3wtpjdz3okul@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      
        and an empty message aborts the commit.
      34221118
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Deref sys_enter pointer args with contents from probe:vfs_getname · f994592d
      Arnaldo Carvalho de Melo authored
      To work like strace and dereference syscall pointer args we need to
      insert probes (or tracepoints) right after we copy those bytes from
      userspace.
      
      Since we're formatting the syscall args at raw_syscalls:sys_enter time,
      we need to have a formatter that just stores the position where, later,
      when we get the probe:vfs_getname, we can insert the pointer contents.
      
      Now, if a probe:vfs_getname with this format is in place:
      
       # perf probe -l
        probe:vfs_getname (on getname_flags:72@/home/git/linux/fs/namei.c with pathname)
      
      That was, in this case, put in place with:
      
       # perf probe 'vfs_getname=getname_flags:72 pathname=filename:string'
       Added new event:
        probe:vfs_getname    (on getname_flags:72 with pathname=filename:string)
      
       You can now use it in all perf tools, such as:
      
      	perf record -e probe:vfs_getname -aR sleep 1
       #
      
      Then 'perf trace' will notice that and do the pointer -> contents
      expansion:
      
       # trace -e open touch /tmp/bla
        0.165 (0.010 ms): touch/17752 open(filename: /etc/ld.so.cache, flags: CLOEXEC) = 3
        0.195 (0.011 ms): touch/17752 open(filename: /lib64/libc.so.6, flags: CLOEXEC) = 3
        0.512 (0.012 ms): touch/17752 open(filename: /usr/lib/locale/locale-archive, flags: CLOEXEC) = 3
        0.582 (0.012 ms): touch/17752 open(filename: /tmp/bla, flags: CREAT|NOCTTY|NONBLOCK|WRONLY, mode: 438) = 3
       #
      
      Roughly equivalent to strace's output:
      
       # strace -rT -e open touch /tmp/bla
        0.000000 open("/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3 <0.000039>
        0.000317 open("/lib64/libc.so.6", O_RDONLY|O_CLOEXEC) = 3 <0.000102>
        0.001461 open("/usr/lib/locale/locale-archive", O_RDONLY|O_CLOEXEC) = 3 <0.000072>
        0.000405 open("/tmp/bla", O_WRONLY|O_CREAT|O_NOCTTY|O_NONBLOCK, 0666) = 3 <0.000055>
        0.000641 +++ exited with 0 +++
       #
      
      Now we need to either look for at all syscalls that are marked as
      pointers and have some well known names ("filename", "pathname", etc)
      and set the arg formatter to the one used for the "open" syscall in this
      patch.
      
      This implementation works for syscalls with just a string being copied
      from userspace, for matching syscalls with more than one string being
      copied via the same probe/trace point (vfs_getname) we need to extend
      the vfs_getname probe spec to include the pointer too, but there are
      some problems with that in 'perf probe' or the kernel kprobes code, need
      to investigate before considering supporting multiple strings per
      syscall.
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Milian Wolff <mail@milianw.de>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Link: http://lkml.kernel.org/n/tip-xvuwx6nuj8cf389kf9s2ue2s@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      f994592d
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Use a constant for the syscall formatting buffer · e4d44e83
      Arnaldo Carvalho de Melo authored
      We were using it as a magic number, 1024, fix that.
      
      Eventually we need to stop doing it per line, and do it per
      arg, traversing the args at output time, to avoid the memmove()
      calls that will be used in the next cset to replace pointers
      present at raw_syscalls:sys_enter time with its contents that
      appear at probe:vfs_getname time, before raw_syscalls:sys_exit
      time.
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Milian Wolff <mail@milianw.de>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Link: http://lkml.kernel.org/n/tip-4sz3wid39egay1pp8qmbur4u@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      e4d44e83
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Remember if the vfs_getname tracepoint/kprobe is in place · 08c98776
      Arnaldo Carvalho de Melo authored
      So that we can later decide if we will store where to expand the
      pathname once we are handling vfs_getname or if we should instead
      just go on and straight away print the pointer.
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Milian Wolff <mail@milianw.de>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Link: http://lkml.kernel.org/n/tip-ytxk5s5jpc50wahffmlxgxuw@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      08c98776
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Do not show syscall tracepoint filter in the --no-syscalls case · 2e5e5f87
      Arnaldo Carvalho de Melo authored
      We were accessing trace->syscalls.events members even when that struct
      wasn't initialized, i.e. --no-syscalls was specified on the command
      line, fix it to show that, still in debug mode, when we have an event
      qualifier list, i.e. when we actually are doing subset syscall tracing.
      
      Cc: Adrian Hunter <adrian.hunter@intel.com>
      Cc: Borislav Petkov <bp@suse.de>
      Cc: David Ahern <dsahern@gmail.com>
      Cc: Frederic Weisbecker <fweisbec@gmail.com>
      Cc: Jiri Olsa <jolsa@redhat.com>
      Cc: Milian Wolff <mail@milianw.de>
      Cc: Namhyung Kim <namhyung@kernel.org>
      Cc: Stephane Eranian <eranian@google.com>
      Fixes: 19867b61 ("perf trace: Use event filters for the event qualifier list")
      Link: http://lkml.kernel.org/n/tip-7980ym6vujgh3yiai0cqzc88@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      2e5e5f87
  2. 04 Aug, 2015 31 commits
  3. 31 Jul, 2015 3 commits