On Mon, May 06, 2013 at 10:44:56AM +0900, Namhyung Kim wrote: > Hi Jiri, > > Sorry for late reply. I've been busy these days. > > On Thu, 25 Apr 2013 15:24:18 +0900, Namhyung Kim wrote: > > On Wed, 24 Apr 2013 16:12:41 +0200, Jiri Olsa wrote: > >> I got following lockup for record command: > >> > >> # ./perf --no-pager ftrace record ls > >> ... > >> hangs > >> > >> in other terminal: > >> > >> # pstack 14237 > >> Thread 2 (Thread 0x7f3f1aa1d700 (LWP 14241)): > >> #0 0x0000003cec20b595 in pthread_cond_wait@@GLIBC_2.3.2 () from > >> /lib64/libpthread.so.0 > >> #1 0x0000000000446ebe in record_ftrace_raw_buffer (arg=0x21f9ce0) at > >> builtin-ftrace.c:451 > >> #2 0x0000003cec207d14 in start_thread () from /lib64/libpthread.so.0 > >> #3 0x0000003cebaf168d in clone () from /lib64/libc.so.6 > >> Thread 1 (Thread 0x7f3f1ba209c0 (LWP 14237)): > >> #0 0x0000003cec208e60 in pthread_join () from /lib64/libpthread.so.0 > >> #1 0x0000000000449c8c in do_ftrace_record > >> (ftrace=ftrace@entry=0x7fff1377d240) at builtin-ftrace.c:682 > >> #2 0x000000000044a57b in __cmd_ftrace_record (argv=0x7fff1377d818, > >> argc=<optimized out>, ftrace=0x7fff1377d240) at builtin-ftrace.c:1535 > >> #3 cmd_ftrace (argc=2, argv=0x7fff1377d818, prefix=<optimized out>) at > >> builtin-ftrace.c:1655 > >> #4 0x000000000041a763 in run_builtin (p=p@entry=0x7d58a0, > >> argc=argc@entry=3, argv=argv@entry=0x7fff1377d818) at perf.c:320 > >> #5 0x0000000000419faf in handle_internal_command (argv=0x7fff1377d818, > >> argc=3) at perf.c:377 > >> #6 run_argv (argv=0x7fff1377d600, argcp=0x7fff1377d60c) at perf.c:421 > >> #7 main (argc=3, argv=0x7fff1377d818) at perf.c:522 > >> > > > > How often can you reproduce it? I can't. :( > > > > But it looks there's a race between cond_wait() and cond_broatcast(). > > I'll take a look at that. > > I think the problem is that a recorder can be blocked if it received a > broadcast signal before calling cond_wait(). So I modified the code to > place signaling ready_cond and waiting start_cond in the same cs. > > Does the patch below fix your problem?
yes.. without the patch I get lockup in like 10 minutes with the patch the test is now ok for almost an hour.. jirka -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
