On 130813 11:20:52, Namhyung Kim wrote:
> ------------8<-------------
> diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c
> index 9e78ec19caeb..10590b794cae 100644
> --- a/tools/perf/builtin-ftrace.c
> +++ b/tools/perf/builtin-ftrace.c
> @@ -555,17 +555,25 @@ sleep:
> while (true) {
> int n = read(trace_fd, buf, sizeof(buf));
>
> - if (n < 0)
> - goto out_close;
> - if (n == 0)
> + if (n < 0) {
> + if (errno == EINTR || errno == EAGAIN)
> + break;
> + perror("flush read");
> + goto out_close2;
> + } else if (n == 0)
> break;
> - if (write(output_fd, buf, n) != n)
> - goto out_close;
> +
> + if (write(output_fd, buf, n) != n) {
> + perror("flush write");
> + goto out_close2;
> + }
>
> byte_written += n;
> }
> fra->state = RECORD_STATE__DONE;
>
> +out_close2:
> + close(output_fd);
> out_close:
> close(trace_fd);
> out:
> @@ -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.
> @@ -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.
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
Thanks!
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