kernel/tools/perf/builtin-ftrace.c, branch linux-4.17.y

perf ftrace: Append an EOL when write tracing files

2018-02-19T12:49:12Z

Before this change, the '--graph-funcs', '--nograph-funcs' and '--trace-funcs' options didn't work as expected when the doesn't exist. Because the kernel side hid possible errors. $ sudo ./perf ftrace -a --graph-depth 1 --graph-funcs abcdefg 0) 0.140 us | rcu_all_qs(); 3) 0.304 us | mutex_unlock(); 0) 0.153 us | find_vma(); 3) 0.088 us | __fsnotify_parent(); 0) 6.145 us | handle_mm_fault(); 3) 0.089 us | fsnotify(); 3) 0.161 us | __sb_end_write(); 3) 0.710 us | SyS_close(); 3) 7.848 us | exit_to_usermode_loop(); On the example above, I specified the function filter 'abcdefg' but all functions are enabled. The expected result is for all functions to be filtered, since there is no such function ('abcdefg') The original fix is to make the kernel support '\0' as end of string: https://lkml.org/lkml/2018/1/16/116 But above fix cannot be compatible with old kernels. Then Namhyung Kim suggest adding a space after function name. This patch will append an '\n' when write tracing file. After this fix, the perf will report correct error state. Also let it print an error if reset_tracing_files() fails. Committer testing: Now it prints: # perf ftrace -a --graph-depth 1 --graph-funcs abcdefg failed to set tracing filters # And for an existing function: # perf ftrace -a --graph-depth 1 --graph-funcs SyS_open 3) | SyS_open() { 3) ! 494.899 us | } 0) + 23.910 us | SyS_open(); 1) + 17.115 us | SyS_open(); 1) + 13.900 us | SyS_open(); ------------------------------------------ 3) qemu-sy-2817 => pickup-1290 ------------------------------------------ 3) + 20.021 us | SyS_open(); # Signed-off-by: Changbin Du Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/1519007609-14551-1-git-send-email-changbin.du@intel.com Signed-off-by: Arnaldo Carvalho de Melo

tools include: Adopt strstarts() from the kernel

2017-07-20T18:46:10Z

Replacing prefixcmp(), same purpose, inverted result, so standardize on the kernel variant, to reduce silly differences among tools/ and the kernel sources, making it easier for people to work in both codebases. And then doing: if (strstarts(option, "no-")) Looks clearer than doing: if (!prefixcmp(option, "no-")) To figure out if option starts witn "no-". Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Josh Poimboeuf Cc: Namhyung Kim Cc: Rusty Russell Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-kaei42gi7lpa8subwtv7eug8@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf ftrace: Add -D option for depth filter

2017-06-20T01:05:54Z

The -D/--graph-depth option is to set max graph depth. The following example traces max 2-depth of page fault handler. $ sudo perf ftrace -G __do_page_fault -D 2 -- hello ... 0) | __do_page_fault() { 0) 0.063 us | down_read_trylock(); 0) 0.251 us | find_vma(); 0) 5.374 us | handle_mm_fault(); 0) 0.054 us | up_read(); 0) 7.463 us | } ... Signed-off-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Steven Rostedt Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170618142302.25390-4-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf ftrace: Add option for function filtering

2017-06-20T01:05:53Z

The -T/--trace-funcs and -N/--notrace-funcs options are to specify functions to enable/disable tracing dynamically. The -G/--graph-funcs and -g/--nograph-funcs options are to set filters for function graph tracer. For example, to trace fault handling functions only: $ sudo perf ftrace -T *fault hello 0) | __do_page_fault() { 0) | handle_mm_fault() { 0) 2.117 us | __handle_mm_fault(); 0) 3.627 us | } 0) 7.811 us | } 0) | __do_page_fault() { 0) | handle_mm_fault() { 0) 2.014 us | __handle_mm_fault(); 0) 2.424 us | } 0) 2.951 us | } ... To trace all functions executed in __do_page_fault: $ sudo perf ftrace -G __do_page_fault hello 2) | __do_page_fault() { 3) 0.060 us | down_read_trylock(); 3) | find_vma() { 3) 0.075 us | vmacache_find(); 3) 0.053 us | vmacache_update(); 3) 1.246 us | } 3) | handle_mm_fault() { 3) 0.063 us | __rcu_read_lock(); 3) 0.056 us | mem_cgroup_from_task(); 3) 0.057 us | __rcu_read_unlock(); 3) | __handle_mm_fault() { 3) | filemap_map_pages() { 3) 0.058 us | __rcu_read_lock(); 3) | alloc_set_pte() { ... But don't want to show details in handle_mm_fault: $ sudo perf ftrace -G __do_page_fault -g handle_mm_fault hello 3) | __do_page_fault() { 3) 0.049 us | down_read_trylock(); 3) | find_vma() { 3) 0.048 us | vmacache_find(); 3) 0.041 us | vmacache_update(); 3) 0.680 us | } 3) 0.036 us | up_read(); 3) 4.547 us | } /* __do_page_fault */ ... Signed-off-by: Namhyung Kim Tested-by: Arnaldo Carvalho de Melo Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Steven Rostedt Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170618142302.25390-3-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf ftrace: Move setup_pager before opening trace_pipe

2017-06-20T01:05:52Z

The 'perf ftrace' command fails to reset tracer after finishing recording like below: $ sudo perf ftrace -v hello write 'nop' to tracing/current_tracer failed: Device or resource busy ... This is because the trace_pipe file is open in pager process. Move the pager setup to before opening the file. Signed-off-by: Namhyung Kim Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Steven Rostedt Cc: kernel-team@lge.com Fixes: 583359646fde ("perf ftrace: Use pager for displaying result") Link: http://lkml.kernel.org/r/20170618142302.25390-2-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf ftrace: Show error message when fails to set ftrace files

2017-06-20T01:05:51Z

It'd be better for debugging to show an error message when it fails to setup ftrace for some reason. Signed-off-by: Namhyung Kim Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Steven Rostedt Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170618142302.25390-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Remove poll.h and wait.h from util.h

2017-04-24T16:43:34Z

Not needed in this header, added to the places that need poll(), wait() and a few other prototypes. Link: http://lkml.kernel.org/n/tip-i39c7b6xmo1vwd9wxp6fmkl0@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Use api/fs/tracing_path.h where needed

2017-04-19T16:01:54Z

Instead of getting it out of luck from util.h, where it isn't needed at all. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-0bqugg5lc5ksla1v4m0dnmc1@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Include errno.h where needed

2017-04-19T16:01:51Z

Removing it from util.h, part of an effort to disentangle the includes hell, that makes changes to util.h or something included by it to cause a complete rebuild of the tools. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-ztrjy52q1rqcchuy3rubfgt2@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Remove unused 'prefix' from builtin functions

2017-03-27T14:58:09Z

We got it from the git sources but never used it for anything, with the place where this would be somehow used remaining: static int run_builtin(struct cmd_struct *p, int argc, const char **argv) { prefix = NULL; if (p->option & RUN_SETUP) prefix = NULL; /* setup_perf_directory(); */ Ditch it. Cc: Adrian Hunter Cc: David Ahern Cc: Jiri Olsa Cc: Namhyung Kim Cc: Wang Nan Link: http://lkml.kernel.org/n/tip-uw5swz05vol0qpr32c5lpvus@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo