Re: [PATCHSET 0/9] perf report: Support folded callchain output (v5)

From: Namhyung Kim
Date: Mon Nov 16 2015 - 18:09:49 EST


Hi Brendan and Arnaldo,

On Thu, Nov 12, 2015 at 09:50:21AM -0800, Brendan Gregg wrote:
> On Sun, Nov 8, 2015 at 9:45 PM, Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
> > Hello,
> >
> > This is what Brendan requested on the perf-users mailing list [1] to
> > support FlameGraphs [2] more efficiently. This patchset adds a few
> > more callchain options to adjust the output for it.
> >
> > * changes in v5)
> > - honor field separator from -t option
> > - add support for TUI and GTK
> >
> > * changes in v4)
> > - add missing doc update
> > - cleanup/fix callchain value print code
> > - add Acked-by from Brendan and Jiri
> >
> > * changes in v3)
> > - put the value before callchains
> > - fix compile error
> >
> >
> > At first, 'folded' output mode was added. The folded output puts the
> > value, a space and all calchain nodes separated by semicolons. Now it
> > only supports --stdio as other UI provides some way of folding and/or
> > expanding callchains dynamically.
> >
> > The value is now can be one of 'percent', 'period', or 'count'. The
> > percent is current default output and the period is the raw number of
> > sample periods. The count is the number of samples for each callchain.
> >
> > The proposed features of hiding hist lines with '-F none' and showing
> > hist info with callchains can be added as later work.
> >
> > Here's an example:
> >
> > $ perf report --no-children --show-nr-samples --stdio -g folded,count
> > ...
> > 39.93% 80 swapper [kernel.vmlinux] [k] intel_idel
> > 57 intel_idle;cpuidle_enter_state;cpuidle_enter;call_cpuidle;cpu_startup_entry;start_secondary
> > 23 intel_idle;cpuidle_enter_state;cpuidle_enter;call_cpuidle;cpu_startup_entry;rest_init;...
> >
>
> Thanks, I tested it, it works!
>
> It lets me do this:
>
> # ./perf report --no-children -n --stdio -g folded,count -F pid
> [...]
> 0:swapper
> 1032 xen_hypercall_sched_op;default_idle;arch_cpu_idle;default_idle_call;cpu_startup_entry;cpu_bringup_and_idle
> 134 xen_hypercall_sched_op;default_idle;arch_cpu_idle;default_idle_call;cpu_startup_entry;rest_init;start_kernel;x86_64_start_reservations;xen_start_kernel
> 1 xen_hypercall_xen_version;check_events;__schedule;schedule;schedule_preempt_disabled;cpu_startup_entry;cpu_bringup_and_idle
> 1 xen_hypercall_xen_version;check_events;cpu_startup_entry;rest_init;start_kernel;x86_64_start_reservations;xen_start_kernel
> 1248:bash
> 43 copy_page_range;copy_process;_do_fork;sys_clone;entry_SYSCALL_64_fastpath;__libc_fork;make_child
> 6 xen_hypercall_xen_version;check_events;xen_dup_mmap;copy_process;_do_fork;sys_clone;entry_SYSCALL_64_fastpath;__libc_fork;make_child
> 4 xen_hypercall_xen_version;check_events;copy_page_range;copy_process;_do_fork;sys_clone;entry_SYSCALL_64_fastpath;__libc_fork;make_child
> [...]
>
> This is a parsable call chain summary, and which can be flamegraph'd
> after a touch of awk. Later on we can add a "-F none" and "-g pid"
> etc, but this patch solves the number one issue of avoiding the
> expense of needing to re-aggregate the call chain output (output of
> perf script), so I'd be pretty happy to use this instead.

Thank you for testing.

Arnaldo, could you please take a look at this?

Thanks,
Namhyung


>
> >
> > $ perf report --no-children --stdio -g percent
> > ...
> > 39.93% swapper [kernel.vmlinux] [k] intel_idel
> > |
> > ---intel_idle
> > cpuidle_enter_state
> > cpuidle_enter
> > call_cpuidle
> > cpu_startup_entry
> > |
> > |--28.63%-- start_secondary
> > |
> > --11.30%-- rest_init
> >
> >
> > $ perf report --no-children --stdio --show-total-period -g period
> > ...
> > 39.93% 13018705 swapper [kernel.vmlinux] [k] intel_idel
> > |
> > ---intel_idle
> > cpuidle_enter_state
> > cpuidle_enter
> > call_cpuidle
> > cpu_startup_entry
> > |
> > |--9334403-- start_secondary
> > |
> > --3684302-- rest_init
> >
> >
> > $ perf report --no-children --stdio --show-nr-samples -g count
> > ...
> > 39.93% 80 swapper [kernel.vmlinux] [k] intel_idel
> > |
> > ---intel_idle
> > cpuidle_enter_state
> > cpuidle_enter
> > call_cpuidle
> > cpu_startup_entry
> > |
> > |--57-- start_secondary
> > |
> > --23-- rest_init
> >
> >
> > You can get it from 'perf/callchain-fold-v5' branch on my tree:
> >
> > git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git
> >
> > Any comments are welcome, thanks
> > Namhyung
> >
> >
> > [1] http://www.spinics.net/lists/linux-perf-users/msg02498.html
> > [2] http://www.brendangregg.com/FlameGraphs/cpuflamegraphs.html
> >
> >
> > Namhyung Kim (9):
> > perf report: Support folded callchain mode on --stdio
> > perf callchain: Abstract callchain print function
> > perf callchain: Add count fields to struct callchain_node
> > perf report: Add callchain value option
> > perf hists browser: Factor out hist_browser__show_callchain_list()
> > perf hists browser: Support flat callchains
> > perf hists browser: Support folded callchains
> > perf ui/gtk: Support flat callchains
> > perf ui/gtk: Support folded callchains
> >
> > tools/perf/Documentation/perf-report.txt | 14 +-
> > tools/perf/builtin-report.c | 4 +-
> > tools/perf/ui/browsers/hists.c | 316 ++++++++++++++++++++++++++++---
> > tools/perf/ui/gtk/hists.c | 148 ++++++++++++++-
> > tools/perf/ui/stdio/hist.c | 94 +++++++--
> > tools/perf/util/callchain.c | 135 ++++++++++++-
> > tools/perf/util/callchain.h | 28 ++-
> > tools/perf/util/util.c | 3 +-
> > 8 files changed, 679 insertions(+), 63 deletions(-)
> >
> > --
> > 2.6.2
> >
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