Messages in this thread | | | Date | Mon, 6 Feb 2017 09:51:49 -0300 | From | Arnaldo Carvalho de Melo <> | Subject | Re: [PATCHSET 0/3] perf diff: Introduce delta-abs compute method |
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Em Mon, Feb 06, 2017 at 04:20:34PM +0900, Namhyung Kim escreveu: > Hello, > > This patchset adds 'delta-abs' compute method to -c/--compute option. > The 'delta-abs' is same as 'delta' but shows entries with bigger > absolute delta first instead of sorting numerically. This is only > useful together with -o option. > > Below is default output (-c delta): > > $ perf diff -o 1 -c delta | grep -v ^# | head > 42.22% +4.97% [kernel.kallsyms] [k] cfb_imageblit > 0.62% +1.23% [kernel.kallsyms] [k] mutex_lock > +1.15% [kernel.kallsyms] [k] copy_user_generic_string > 2.40% +0.95% [kernel.kallsyms] [k] bit_putcs > 0.31% +0.79% [kernel.kallsyms] [k] link_path_walk > +0.64% [kernel.kallsyms] [k] kmem_cache_alloc > 0.00% +0.57% [kernel.kallsyms] [k] __rcu_read_unlock > +0.45% [kernel.kallsyms] [k] alloc_set_pte > 0.16% +0.45% [kernel.kallsyms] [k] menu_select > +0.41% ld-2.24.so [.] do_lookup_x > > Now with 'delta-abs' it shows entries have bigger delta value either > positive or negative. > > $ perf diff -o 1 -c delta-abs | grep -v ^# | head > 42.22% +4.97% [kernel.kallsyms] [k] cfb_imageblit > 12.72% -3.01% [kernel.kallsyms] [k] intel_idle > 9.72% -1.31% [unknown] [.] 0x0000000000411343 > 0.62% +1.23% [kernel.kallsyms] [k] mutex_lock > +1.15% [kernel.kallsyms] [k] copy_user_generic_string > 2.40% +0.95% [kernel.kallsyms] [k] bit_putcs > 0.31% +0.79% [kernel.kallsyms] [k] link_path_walk > 1.35% -0.71% [kernel.kallsyms] [k] smp_call_function_single > +0.64% [kernel.kallsyms] [k] kmem_cache_alloc > 0.00% +0.57% [kernel.kallsyms] [k] __rcu_read_unlock > > The patch 2 and 3 are to add config options to control the default > behavior of perf diff command. I think that it's worth consider > changing the default to use 'delta-abs' method since users want to see > where the difference occurs actually (either positive or negative) IMHO.
I agree on having the default changed to 'delta-abs', Ingo?
Namhyung, and perhaps we should have a single letter option to do that '| grep -v ^#' bit :-) and perhaps we also should have, for all tools the equivalent of that "| head", that git log has:
[acme@jouet linux]$ git log --oneline -5 d7cb3a507d23 Merge tag 'perf-core-for-mingo-4.11-20170201' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core 5443624bedd0 perf/x86/intel/pt: Add format strings for PTWRITE and power event tracing b05d1093987a perf ftrace: Add ftrace.tracer config option 43d41deb71fe perf tools: Create for_each_event macro for tracepoints iteration a26305363d4b perf test: Add libbpf pinning test [acme@jouet linux]$
That '-5' to show just the first 5 lines worth of output.
With all that we would have:
perf diff -o 1 -q10
As the equivalent to "perf diff -o 1 -c delta-abs | grep -v ^# | head".
Ah, adding Paul McKenney to the CC list, he may have something to add here.
- Arnaldo > The code is avaiable at 'perf/diff-delta-abs-v1' branch in > > git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git > > Thanks, > Namhyung > > > Namhyung Kim (3): > perf diff: Add 'delta-abs' compute method > perf diff: Add diff.order config option > perf diff: Add diff.compute config option > > tools/perf/Documentation/perf-config.txt | 12 +++++ > tools/perf/Documentation/perf-diff.txt | 15 +++++-- > tools/perf/builtin-diff.c | 76 ++++++++++++++++++++++++++++++-- > 3 files changed, 97 insertions(+), 6 deletions(-) > > -- > 2.11.0
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