kernel/linux.git/tools/perf/Documentation, branch v3.13.3

perf record: Add an option to force per-cpu mmaps

2013-11-14T19:10:27+00:00

By default, when tasks are specified (i.e. -p, -t or -u options) per-thread mmaps are created. Add an option to override that and force per-cpu mmaps. Further comments by peterz: So this option allows -t/-p/-u to create one buffer per cpu and attach all the various thread/process/user tasks' their counters to that one buffer? As opposed to the current state where each such counter would have its own buffer. Signed-off-by: Adrian Hunter Tested-by: Sukadev Bhattiprolu Acked-by: Peter Zijlstra Cc: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1383313899-15987-7-git-send-email-adrian.hunter@intel.com Signed-off-by: Arnaldo Carvalho de Melo

perf trace: Add summary only option

2013-11-12T19:24:38+00:00

Per request from Pekka make --summary a summary only option meaning do not show the individual system calls. Add another option to see all syscalls along with the summary. In addition use 's' and 'S' as shortcuts for the options. Requested-by: Pekka Enberg Signed-off-by: David Ahern Tested-by: Pekka Enberg Cc: Adrian Hunter Cc: Ingo Molnar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Pekka Enberg Link: http://lkml.kernel.org/r/1384273875-3751-1-git-send-email-dsahern@gmail.com Signed-off-by: Arnaldo Carvalho de Melo

Merge branch 'perf/urgent' into perf/core

2013-10-29T10:23:32+00:00

Conflicts: tools/perf/builtin-record.c tools/perf/builtin-top.c tools/perf/util/hist.h

perf top: Split -G and --call-graph

2013-10-28T19:06:00+00:00

Splitting -G and --call-graph for record command, so we could use '-G' with no option. The '-G' option now takes NO argument and enables the configured unwind method, which is currently the frame pointers method. It will be possible to configure unwind method via config file in upcoming patches. All current '-G' arguments is overtaken by --call-graph option. NOTE: The documentation for top --call-graph option was wrongly copied from report command. Signed-off-by: Jiri Olsa Tested-by: David Ahern Tested-by: Ingo Molnar Reviewed-by: David Ahern Acked-by: Ingo Molnar Cc: Adrian Hunter Cc: Andi Kleen Cc: Corey Ashford Cc: David Ahern Cc: Ingo Molnar Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1382797536-32303-3-git-send-email-jolsa@redhat.com Signed-off-by: Arnaldo Carvalho de Melo

perf record: Split -g and --call-graph

2013-10-28T19:05:59+00:00

Splitting -g and --call-graph for record command, so we could use '-g' with no option. The '-g' option now takes NO argument and enables the configured unwind method, which is currently the frame pointers method. It will be possible to configure unwind method via config file in upcoming patches. All current '-g' arguments is overtaken by --call-graph option. Signed-off-by: Jiri Olsa Tested-by: David Ahern Tested-by: Ingo Molnar Reviewed-by: David Ahern Acked-by: Ingo Molnar Cc: Adrian Hunter Cc: Andi Kleen Cc: Corey Ashford Cc: David Ahern Cc: Ingo Molnar Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1382797536-32303-2-git-send-email-jolsa@redhat.com [ reordered -g/--call-graph on --help and expanded the man page according to comments by David Ahern and Namhyung Kim ] Signed-off-by: Arnaldo Carvalho de Melo

perf top: Add --max-stack option to limit callchain stack scan

2013-10-21T20:36:25+00:00

When the callgraph function is enabled (-G), it may take a long time to scan all the stack data and merge them accordingly. This patch adds a new --max-stack option to perf-top to limit the depth of callchain stack data to look at to reduce the time it takes for perf-top to finish its processing. It reduces the amount of information provided to the user in exchange for faster speed. Signed-off-by: Waiman Long Acked-by: David Ahern Tested-by: Davidlohr Bueso Cc: Adrian Hunter Cc: Aswin Chandramouleeswaran Cc: David Ahern Cc: Ingo Molnar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Scott J Norton Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1382107129-2010-5-git-send-email-Waiman.Long@hp.com Signed-off-by: Arnaldo Carvalho de Melo

perf report: Add --max-stack option to limit callchain stack scan

2013-10-21T20:36:25+00:00

When callgraph data was included in the perf data file, it may take a long time to scan all those data and merge them together especially if the stored callchains are long and the perf data file itself is large, like a Gbyte or so. The callchain stack is currently limited to PERF_MAX_STACK_DEPTH (127). This is a large value. Usually the callgraph data that developers are most interested in are the first few levels, the rests are usually not looked at. This patch adds a new --max-stack option to perf-report to limit the depth of callchain stack data to look at to reduce the time it takes for perf-report to finish its processing. It trades the presence of trailing stack information with faster speed. The following table shows the elapsed time of doing perf-report on a perf.data file of size 985,531,828 bytes. --max_stack Elapsed Time Output data size ----------- ------------ ---------------- not set 88.0s 124,422,651 64 87.5s 116,303,213 32 87.2s 112,023,804 16 86.6s 94,326,380 8 59.9s 33,697,248 4 40.7s 10,116,637 -g none 27.1s 2,555,810 Signed-off-by: Waiman Long Acked-by: David Ahern Cc: Adrian Hunter Cc: Aswin Chandramouleeswaran Cc: David Ahern Cc: Ingo Molnar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Scott J Norton Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1382107129-2010-4-git-send-email-Waiman.Long@hp.com Signed-off-by: Arnaldo Carvalho de Melo

perf trace: Use vfs_getname hook if available

2013-10-16T14:18:24+00:00

Initially it tries to find a probe:vfs_getname that should be setup with: perf probe 'vfs_getname=getname_flags:65 pathname=result->name:string' or with slight changes to cope with code flux in the getname_flags code. In the future, if a "vfs:getname" tracepoint becomes available, then it will be preferred. This is not strictly required and more expensive method of reading the /proc/pid/fd/ symlink will be used when the fd->path array entry is not populated by a previous vfs_getname + open syscall ret sequence. As with any other 'perf probe' probe the setup must be done just once and the probe will be left inactive, waiting for users, be it 'perf trace' of any other tool. Cc: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Mike Galbraith Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/n/tip-ujg8se8glq5izmu8cdkq15po@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf buildid-cache: Add ability to add kcore to the cache

2013-10-14T15:20:38+00:00

kcore can be used to view the running kernel object code. However, kcore changes as modules are loaded and unloaded, and when the kernel decides to modify its own code. Consequently it is useful to create a copy of kcore at a particular time. Unlike vmlinux, kcore is not unique for a given build-id. And in addition, the kallsyms and modules files are also needed. The tool therefore creates a directory: ~/.debug/[kernel.kcore]// which contains: kcore, kallsyms and modules. Note that the copied kcore contains only code sections. See the kcore_copy() function for how that is determined. The tool will not make additional copies of kcore if there is already one with the same modules at the same addresses. Currently, perf tools will not look for kcore in the cache. That is addressed in another patch. Signed-off-by: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Mike Galbraith Cc: Namhyung Kim Cc: Paul Mackerras Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/525BF849.5030405@intel.com [ renamed 'index' to 'idx' to avoid shadowing string.h symbol in f12, use at least one member initializer when initializing a struct to zeros, also to fix the build on f12 ] Signed-off-by: Arnaldo Carvalho de Melo

perf trace: Add summary option to dump syscall statistics

2013-10-14T13:28:50+00:00

When enabled dumps a summary of all syscalls by task with the usual statistics -- min, max, average and relative stddev. For example, make - 26341 : 3344 [ 17.4% ] 0.000 ms read : 52 0.000 4.802 0.644 30.08 write : 20 0.004 0.036 0.010 21.72 open : 24 0.003 0.046 0.014 23.68 close : 64 0.002 0.055 0.008 22.53 stat : 2714 0.002 0.222 0.004 4.47 fstat : 18 0.001 0.041 0.006 46.26 mmap : 30 0.003 0.009 0.006 5.71 mprotect : 8 0.006 0.039 0.016 32.16 munmap : 12 0.007 0.077 0.020 38.25 brk : 48 0.002 0.014 0.004 10.18 rt_sigaction : 18 0.002 0.002 0.002 2.11 rt_sigprocmask : 60 0.002 0.128 0.010 32.88 access : 2 0.006 0.006 0.006 0.00 pipe : 12 0.004 0.048 0.013 35.98 vfork : 34 0.448 0.980 0.692 3.04 execve : 20 0.000 0.387 0.046 56.66 wait4 : 34 0.017 9923.287 593.221 68.45 fcntl : 8 0.001 0.041 0.013 48.79 getdents : 48 0.002 0.079 0.013 19.62 getcwd : 2 0.005 0.005 0.005 0.00 chdir : 2 0.070 0.070 0.070 0.00 getrlimit : 2 0.045 0.045 0.045 0.00 arch_prctl : 2 0.002 0.002 0.002 0.00 setrlimit : 2 0.002 0.002 0.002 0.00 openat : 94 0.003 0.005 0.003 2.11 Signed-off-by: David Ahern Cc: Frederic Weisbecker Cc: Ingo Molnar Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Stephane Eranian Link: http://lkml.kernel.org/r/1381289214-24885-3-git-send-email-dsahern@gmail.com Signed-off-by: Arnaldo Carvalho de Melo