Messages in this thread | | | From | Namhyung Kim <> | Subject | Re: [PATCHSET 00/17] perf tools: Introduce new 'ftrace' command (v4) | Date | Thu, 29 Aug 2013 11:56:46 +0900 |
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Hi Jeremy,
On Wed, 28 Aug 2013 10:57:08 -0400, Jeremy Eder wrote: > On 130813 11:20:52, Namhyung Kim wrote: >> @@ -579,6 +587,8 @@ out: >> pthread_cond_signal(&recorder_ready_cond); >> pthread_mutex_unlock(&recorder_mutex); >> } >> + >> + pr_debug2("done with %ld bytes\n", (long)byte_written); >> return fra; >> } >> > > Hmm, I already had hunk #3 in your git tree v4.
Oops, sorry about that.
> >> @@ -1139,12 +1149,12 @@ retry: >> return record; >> } >> >> - munmap(fra->map, pevent_get_page_size(ftrace->pevent)); >> - fra->map = NULL; >> - >> if (fra->done) >> return NULL; >> >> + munmap(fra->map, pevent_get_page_size(ftrace->pevent)); >> + fra->map = NULL; >> + >> fra->offset += pevent_get_page_size(ftrace->pevent); >> if (fra->offset >= fra->size) { >> /* EOF */ > > > After patching your tree with just the first 2 hunks, I'm able to > get ftrace-style function graphing out of perf. > > # ./perf ftrace record df > Filesystem 1K-blocks Used Available Use% Mounted on > <snip>... > > # ./perf --no-pager ftrace show | head -20 > overriding event (11) ftrace:funcgraph_entry with new print handler > overriding event (10) ftrace:funcgraph_exit with new print handler > 2) 0.686 us | finish_task_switch(); > 2) 0.260 us | finish_wait(); > 2) | mutex_lock() { > 2) 0.211 us | _cond_resched(); > 2) 1.170 us | } > 2) 0.319 us | generic_pipe_buf_confirm(); > 2) 0.261 us | generic_pipe_buf_map(); > 2) 0.129 us | generic_pipe_buf_unmap(); > 2) 0.747 us | anon_pipe_buf_release(); > 2) 0.138 us | mutex_unlock(); > 2) | __wake_up_sync_key() { > 2) 0.279 us | _raw_spin_lock_irqsave(); > 2) 0.135 us | __wake_up_common(); > 2) 0.133 us | __lock_text_start(); > 2) 3.386 us | } > 2) | kill_fasync() { > 2) | smp_reschedule_interrupt() { > 2) 0.130 us | kvm_guest_apic_eoi_write(); > > Nice.
Glad to see this. :)
> > Not sure if you intend to move all ftrace functionality over to > perf ftrace, but the function graph timings is a great start and something sorely > missing. > > Do you intend to add -e event support or -l function-specific options ? In the real > world, without filtering on events or functions, I've had systems hang, plus > performance impact is too great. > > A common invocation of ftrace via trace-cmd is: > # trace-cmd record -p function_graph -e irq:* -l do_IRQ ping -c1 www.redhat.com > > So possible perf equivalent? > # ./perf ftrace record -e irq:* -e do_IRQ ping -c1 www.redhat.com
Yes I'm considering adding more features in trace-cmd to perf ftrace. The function filtering is the one in the highest priority. I also want to add support for other events but it needs bit more thinking.
Thanks, Namhyung
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