On Mon, Oct 26, 2020 at 08:47:06PM +0300, Alexey Budankov wrote:
> 
> On 24.10.2020 18:43, Jiri Olsa wrote:
> > On Wed, Oct 21, 2020 at 06:57:53PM +0300, Alexey Budankov wrote:
> >>
> >> Open files located at trace data directory in case read access
> >> mode is requested. File are opened and its fds assigned to
> >> perf_data dir files especially for loading data directories
> >> content in perf report mode.
> >>
> >> Signed-off-by: Alexey Budankov <alexey.budan...@linux.intel.com>
> >> ---
> >>  tools/perf/util/data.c | 4 ++++
> >>  1 file changed, 4 insertions(+)
> >>
> >> diff --git a/tools/perf/util/data.c b/tools/perf/util/data.c
> >> index c47aa34fdc0a..6ad61ac6ba67 100644
> >> --- a/tools/perf/util/data.c
> >> +++ b/tools/perf/util/data.c
> >> @@ -321,6 +321,10 @@ static int open_dir(struct perf_data *data)
> >>            return -1;
> >>  
> >>    ret = open_file(data);
> >> +  if (!ret && perf_data__is_dir(data)) {
> >> +          if (perf_data__is_read(data))
> >> +                  ret = perf_data__open_dir(data);
> >> +  }
> > 
> > perf_data__open_dir is also called from perf_session__new
> > is it called twice?
> 
> It is not called twice. It is in different branches.
> This one is for write and the other one is for read.

hum, is that right?

        # ./perf record --threads 
        ^C[ perf record: Woken up 15 times to write data ]
        [ perf record: Captured and wrote 1.421 MB perf.data (515 samples) ]

        # gdb ./perf
        GNU gdb (GDB) Fedora 9.1-6.fc32

        (gdb) b perf_data__open_dir
        Breakpoint 1 at 0x5b4753: file util/data.c, line 72.

        (gdb) r --no-pager report --stdio
        Starting program: /home/jolsa/kernel/linux-perf/tools/perf/perf 
--no-pager report --stdio

        Breakpoint 1, perf_data__open_dir (data=0x7fffffffb0e0) at 
util/data.c:72
        72      {
        (gdb) bt
        #0  perf_data__open_dir (data=0x7fffffffb0e0) at util/data.c:72
        #1  0x00000000005b538d in open_dir (data=0x7fffffffb0e0) at 
util/data.c:326
        #2  0x00000000005b546d in perf_data__open (data=0x7fffffffb0e0) at 
util/data.c:351
        #3  0x00000000005627e8 in perf_session__new (data=0x7fffffffb0e0, 
repipe=false, tool=0x7fffffffb220) at util/session.c:210
        #4  0x000000000045a572 in cmd_report (argc=0, argv=0x7fffffffd7a8) at 
builtin-report.c:1372
        #5  0x00000000004f49ec in run_builtin (p=0xaadab0 <commands+240>, 
argc=2, argv=0x7fffffffd7a8) at perf.c:312
        #6  0x00000000004f4c59 in handle_internal_command (argc=2, 
argv=0x7fffffffd7a8) at perf.c:364
        #7  0x00000000004f4da0 in run_argv (argcp=0x7fffffffd5ec, 
argv=0x7fffffffd5e0) at perf.c:408
        #8  0x00000000004f516c in main (argc=2, argv=0x7fffffffd7a8) at 
perf.c:538

        (gdb) c
        Continuing.

        Breakpoint 1, perf_data__open_dir (data=0x7fffffffb0e0) at 
util/data.c:72
        72      {
        (gdb) bt
        #0  perf_data__open_dir (data=0x7fffffffb0e0) at util/data.c:72
        #1  0x0000000000562883 in perf_session__new (data=0x7fffffffb0e0, 
repipe=false, tool=0x7fffffffb220) at util/session.c:234
        #2  0x000000000045a572 in cmd_report (argc=0, argv=0x7fffffffd7a8) at 
builtin-report.c:1372
        #3  0x00000000004f49ec in run_builtin (p=0xaadab0 <commands+240>, 
argc=2, argv=0x7fffffffd7a8) at perf.c:312
        #4  0x00000000004f4c59 in handle_internal_command (argc=2, 
argv=0x7fffffffd7a8) at perf.c:364
        #5  0x00000000004f4da0 in run_argv (argcp=0x7fffffffd5ec, 
argv=0x7fffffffd5e0) at perf.c:408
        #6  0x00000000004f516c in main (argc=2, argv=0x7fffffffd7a8) at 
perf.c:538


AFAICS the second (current) call to perf_data__open_dir will
do the job, because the call you added still does not see
directory with proper version and will bail out on call to
  perf_data__is_single_file

perf_session__open call will read headers and update dir version
so the current perf_data__open_dir will open the directory

jirka

Reply via email to