On Tue, Nov 5, 2013 at 1:04 PM, David Ahern <dsah...@gmail.com> wrote: > On 11/4/13, 7:40 AM, wufei wrote: >> >> Hello All, >> >> I am using perf to measure a multi-threaded program on kernel 3.2.23, >> the system has 40 cores and there are lots of context switches during >> the test. The command is: >> # perf record -e sched:sched_stat_sleep -e sched:sched_switch -e >> sched:sched_process_exit -g -r 0 -p 39249 sleep 5 >> It generates a ~1GB size perf.data. `perf report` got 2 issues: >> >> 1. A lot of this warning message: >> Warning: Timestamp below last timeslice flush > > > What's the NUMA make up? multiple sockets? > There are 4 nodes, each one with 10 cores.
> >> >> 2. No useful output, but this: >> Found 32117 unknown events! > > > Try increasing the mmap size. e.g., -m 2048. Does it decrease or remove this > stat? > It helps. There is no such problem again with this option if I only trace it in 2 seconds, but if it's 5 seconds, this problem is still there and another error message: "failed to mmap file" Thanks, Wufei. > David > -- To unsubscribe from this list: send the line "unsubscribe linux-perf-users" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
