Hello, Steven, On Fri, Jan 09, 2015 at 09:19:04AM -0500, Steven Rostedt wrote: > > Wow, too much work over the holidays ;-) Pretend to be diligent. > > > On Tue, 30 Dec 2014 13:47:26 +0900 > Minchan Kim <minchan@xxxxxxxxxx> wrote: > > > > Then, I don't think we could keep all of allocations. What we need > > is only slow allocations. I hope we can do that with ftrace. > > > > ex) > > > > # cd /sys/kernel/debug/tracing > > # echo 1 > options/stacktrace > > # echo cam_alloc > set_ftrace_filter > > # echo your_threshold > tracing_thresh > > > > I know it doesn't work now but I think it's more flexible > > and general way to handle such issues(ie, latency of some functions). > > So, I hope we could enhance ftrace rather than new wheel. > > Ccing ftrace people. > > > > I've been working on trace-cmd this month and came up with a new > "profile" command. I don't have cma_alloc but doing something like this > with kmalloc. > > > # trace-cmd profile -S -p function_graph -l __kmalloc -l '__kmalloc:stacktrace' --stderr workload 2>profile.out > > and this gives me in profile.out, something like this: > > ------ > CPU: 0 > entries: 0 > overrun: 0 > commit overrun: 0 > bytes: 3560 > oldest event ts: 349.925480 > now ts: 356.910819 > dropped events: 0 > read events: 36 > > CPU: 1 > entries: 0 > overrun: 0 > commit overrun: 0 > bytes: 408 > oldest event ts: 354.610624 > now ts: 356.910838 > dropped events: 0 > read events: 48 > > CPU: 2 > entries: 0 > overrun: 0 > commit overrun: 0 > bytes: 3184 > oldest event ts: 356.761870 > now ts: 356.910854 > dropped events: 0 > read events: 1830 > > CPU: 3 > entries: 6 > overrun: 0 > commit overrun: 0 > bytes: 2664 > oldest event ts: 356.440675 > now ts: 356.910875 > dropped events: 0 > read events: 717 > > [...] > > task: <...>-2880 > Event: func: __kmalloc() (74) Total: 53254 Avg: 719 Max: 1095 Min:481 > | > + ftrace_ops_list_func (0xffffffff810c229e) > 100% (74) time:53254 max:1095 min:481 avg:719 > ftrace_call (0xffffffff81526047) > trace_preempt_on (0xffffffff810d28ff) > preempt_count_sub (0xffffffff81061c62) > __mutex_lock_slowpath (0xffffffff81522807) > __kmalloc (0xffffffff811323f3) > __kmalloc (0xffffffff811323f3) > tracing_buffers_splice_read (0xffffffff810ca23e) > | > + set_next_entity (0xffffffff81067027) > | 66% (49) time:34925 max:1044 min:481 avg:712 > | __switch_to (0xffffffff810016d7) > | trace_hardirqs_on (0xffffffff810d28db) > | _raw_spin_unlock_irq (0xffffffff81523a8e) > | trace_preempt_on (0xffffffff810d28ff) > | preempt_count_sub (0xffffffff81061c62) > | __schedule (0xffffffff815204d3) > | trace_preempt_on (0xffffffff810d28ff) > | buffer_spd_release (0xffffffff810c91fd) > | SyS_splice (0xffffffff8115dccf) > | system_call_fastpath (0xffffffff81523f92) > | > + do_read_fault.isra.74 (0xffffffff8111431d) > | 24% (18) time:12654 max:1008 min:481 avg:703 > | | > | + select_task_rq_fair (0xffffffff81067806) > | | 89% (16) time:11234 max:1008 min:481 avg:702 > | | trace_preempt_on (0xffffffff810d28ff) > | | buffer_spd_release (0xffffffff810c91fd) > | | SyS_splice (0xffffffff8115dccf) > | | system_call_fastpath (0xffffffff81523f92) > | | > | + handle_mm_fault (0xffffffff81114df4) > | 11% (2) time:1420 max:879 min:541 avg:710 > | trace_preempt_on (0xffffffff810d28ff) > | buffer_spd_release (0xffffffff810c91fd) > | SyS_splice (0xffffffff8115dccf) > | system_call_fastpath (0xffffffff81523f92) > | > | > | > + update_stats_wait_end (0xffffffff81066c5c) > | 6% (4) time:3153 max:1095 min:635 avg:788 > | set_next_entity (0xffffffff81067027) > | __switch_to (0xffffffff810016d7) > | trace_hardirqs_on (0xffffffff810d28db) > | _raw_spin_unlock_irq (0xffffffff81523a8e) > | trace_preempt_on (0xffffffff810d28ff) > | preempt_count_sub (0xffffffff81061c62) > | __schedule (0xffffffff815204d3) > | trace_preempt_on (0xffffffff810d28ff) > | buffer_spd_release (0xffffffff810c91fd) > | SyS_splice (0xffffffff8115dccf) > | system_call_fastpath (0xffffffff81523f92) > | > + _raw_spin_unlock (0xffffffff81523af5) > | 3% (2) time:1854 max:936 min:918 avg:927 > | do_read_fault.isra.74 (0xffffffff8111431d) > | handle_mm_fault (0xffffffff81114df4) > | buffer_spd_release (0xffffffff810c91fd) > | SyS_splice (0xffffffff8115dccf) > | system_call_fastpath (0xffffffff81523f92) > | > + trace_hardirqs_off (0xffffffff810d2891) > 1% (1) time:668 max:668 min:668 avg:668 > kmem_cache_free (0xffffffff81130e48) > __dequeue_signal (0xffffffff8104c802) > trace_preempt_on (0xffffffff810d28ff) > preempt_count_sub (0xffffffff81061c62) > _raw_spin_unlock_irq (0xffffffff81523a8e) > recalc_sigpending (0xffffffff8104c5d1) > __set_task_blocked (0xffffffff8104cd2e) > trace_preempt_on (0xffffffff810d28ff) > preempt_count_sub (0xffffffff81061c62) > preempt_count_sub (0xffffffff81061c62) > buffer_spd_release (0xffffffff810c91fd) > SyS_splice (0xffffffff8115dccf) > system_call_fastpath (0xffffffff81523f92) > Looks great! > If you want better names, I would add "-e sched_switch", as that will > record the comms of the tasks and you don't end up with a bunch of > "<...>". Good tip. > > Is this something you are looking for. The profile command does not > save to disk, thus it does the analysis live, and you don't need to > worry about running out of disk space. Although, since it is live, it > may tend to drop more events (see the "overrun values"). > > You can get trace-cmd from: > > git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/trace-cmd.git > > You'll need the latest from the master branch, as even 2.5 doesn't have > the --stderr yet. > > Make sure to do a make install and make install_doc, then you can do: > > man trace-cmd-record > man trace-cmd-profile > > to read about all the options. Thansk for giving me a chance to use great tool! > > -- Steve > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@xxxxxxxxx. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a> -- Kind regards, Minchan Kim -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>