[PATCHSET 0/4] perf diff: Introduce delta-abs compute method (v2)

From: Namhyung Kim
Date: Fri Feb 10 2017 - 02:37:41 EST


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.

* v2 changes
- rebase onto acme/perf/core
- change default option to '-o 1 -c delta-abs'


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. And patch 4 changes the default setting.

The code is avaiable at 'perf/diff-delta-abs-v2' branch in

git://git.kernel.org/pub/scm/linux/kernel/git/namhyung/linux-perf.git

Thanks,
Namhyung


Namhyung Kim (4):
perf diff: Add 'delta-abs' compute method
perf diff: Add diff.order config option
perf diff: Add diff.compute config option
perf diff: Change default setting to "delta-abs"

tools/perf/Documentation/perf-config.txt | 12 +++++
tools/perf/Documentation/perf-diff.txt | 15 ++++--
tools/perf/builtin-diff.c | 78 ++++++++++++++++++++++++++++++--
3 files changed, 98 insertions(+), 7 deletions(-)

--
2.11.0