From: Arnaldo Carvalho de Melo <a...@redhat.com>
Previously there were blind spots because we were not looking at symbols
that didn't ocurred in the latest run:
# perf record usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.018 MB perf.data (~801 samples) ]
# perf record usleep 1
[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 0.018 MB perf.data (~801 samples) ]
Before:
# perf diff
# Event 'cycles'
#
# Baseline Delta Shared Object Symbol
# ........ ....... ................. .............................
#
+10.38% [kernel.kallsyms] [k] get_empty_filp
+9.51% [kernel.kallsyms] [k] update_sd_lb_stats
+9.41% libpopt.so.0.0.0 [.] _init
+9.29% [kernel.kallsyms] [k] vma_interval_tree_insert
9.05% +0.12% [kernel.kallsyms] [k] do_sys_open
+9.14% [kernel.kallsyms] [k] kfree
+8.98% [kernel.kallsyms] [k] free_pages_and_swap_cache
+8.78% [kernel.kallsyms] [k] unmap_page_range
9.36% -0.90% [kernel.kallsyms] [k] zap_pte_range
7.60% +0.09% [kernel.kallsyms] [k] find_next_bit
+4.37% [kernel.kallsyms] [k] place_entity
+3.38% [kernel.kallsyms] [k] __do_page_fault
+0.80% [kernel.kallsyms] [k] native_apic_mem_write
0.21% +0.43% [kernel.kallsyms] [k] native_write_msr_safe
#
So 9.05 + 9.36 + 7.60 + 0.21 != 100%
Now using the recently introduced hists__link we can see the whole
picture:
# perf diff
# Event 'cycles'
#
# Baseline Delta Shared Object Symbol
# ........ ....... ................. .............................
#
8.44% -8.44% [kernel.kallsyms] [k] _raw_spin_lock
9.05% -9.05% [kernel.kallsyms] [k] sha_transform
10.55% -10.55% [kernel.kallsyms] [k] __d_lookup_rcu
+10.38% [kernel.kallsyms] [k] get_empty_filp
17.70% -17.70% [kernel.kallsyms] [k] kmem_cache_free
+9.51% [kernel.kallsyms] [k] update_sd_lb_stats
+9.41% libpopt.so.0.0.0 [.] _init
+9.29% [kernel.kallsyms] [k] vma_interval_tree_insert
9.05% +0.12% [kernel.kallsyms] [k] do_sys_open
+9.14% [kernel.kallsyms] [k] kfree
+8.98% [kernel.kallsyms] [k] free_pages_and_swap_cache
+8.78% [kernel.kallsyms] [k] unmap_page_range
9.36% -0.90% [kernel.kallsyms] [k] zap_pte_range
7.60% +0.09% [kernel.kallsyms] [k] find_next_bit
+4.37% [kernel.kallsyms] [k] place_entity
+3.38% [kernel.kallsyms] [k] __do_page_fault
4.01% -4.01% [kernel.kallsyms] [k] handle_pte_fault
9.27% -9.27% [kernel.kallsyms] [k] find_get_page
0.78% -0.78% [kernel.kallsyms] [k] rcu_irq_enter
0.57% -0.57% [kernel.kallsyms] [k] finish_task_switch
4.25% -4.25% [kernel.kallsyms] [k] run_timer_softirq
+0.80% [kernel.kallsyms] [k] native_apic_mem_write
0.21% +0.43% [kernel.kallsyms] [k] native_write_msr_safe
9.16% -9.16% ld-2.12.so [.] close
#
Now:
8.44 + 9.05 + 10.55 + 17.70 + 9.05 + 9.36 +
7.60 + 4.01 + 9.27 + 0.78 + 0.57 + 4.25 + 0.21 + 9.16 == 100%
Cc: David Ahern <dsah...@gmail.com>
Cc: Frederic Weisbecker <fweis...@gmail.com>
Cc: Jiri Olsa <jo...@redhat.com>
Cc: Mike Galbraith <efa...@gmx.de>
Cc: Namhyung Kim <namhy...@gmail.com>
Cc: Paul Mackerras <pau...@samba.org>
Cc: Peter Zijlstra <pet...@infradead.org>
Cc: Stephane Eranian <eran...@google.com>
Link: http://lkml.kernel.org/n/tip-jeq55qdgby1745bs8r9ss...@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
---
tools/perf/builtin-diff.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/tools/perf/builtin-diff.c b/tools/perf/builtin-diff.c
index e99fb3b..93b852f 100644
--- a/tools/perf/builtin-diff.c
+++ b/tools/perf/builtin-diff.c
@@ -491,6 +491,8 @@ static void hists__process(struct hists *old, struct hists
*new)
if (show_baseline_only)
hists__baseline_only(new);
+ else
+ hists__link(new, old);
if (sort_compute) {
hists__precompute(new);
--
1.7.9.2.358.g22243
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