linux_dsm_epyc7002/tools
Jin Yao a3366db06b perf report: Fix wrong iteration count in --branch-history
By calculating the removed loops, we can get the iteration count.

But the iteration count could be reported incorrectly, reporting
impossibly high counts.

That's because previous code uses the number of removed LBR entries for
the iteration count. That's not good. Fix this by increasing the
iteration count when a loop is detected.

When matching the chain, the iteration count would be added up, finally we need
to compute the average value when printing out.

For example,

  $ perf report --branch-history --stdio --no-children

Before:

  ---f2 +0
     |
     |--33.62%--f1 +9 (cycles:1)
     |          f1 +0
     |          main +22 (cycles:1)
     |          main +17
     |          main +38 (cycles:1)
     |          main +27
     |          f1 +26 (cycles:1)
     |          f1 +24
     |          f2 +27 (cycles:7)
     |          f2 +0
     |          f1 +19 (cycles:1)
     |          f1 +14
     |          f2 +27 (cycles:11)
     |          f2 +0
     |          f1 +9 (cycles:1 iter:2968 avg_cycles:3)
     |          f1 +0
     |          main +22 (cycles:1 iter:2968 avg_cycles:3)
     |          main +17
     |          main +38 (cycles:1 iter:2968 avg_cycles:3)

2968 is an impossible high iteration count and avg_cycles is too small.

After:

  ---f2 +0
     |
     |--33.62%--f1 +9 (cycles:1)
     |          f1 +0
     |          main +22 (cycles:1)
     |          main +17
     |          main +38 (cycles:1)
     |          main +27
     |          f1 +26 (cycles:1)
     |          f1 +24
     |          f2 +27 (cycles:7)
     |          f2 +0
     |          f1 +19 (cycles:1)
     |          f1 +14
     |          f2 +27 (cycles:11)
     |          f2 +0
     |          f1 +9 (cycles:1 iter:1 avg_cycles:23)
     |          f1 +0
     |          main +22 (cycles:1 iter:1 avg_cycles:23)
     |          main +17
     |          main +38 (cycles:1 iter:1 avg_cycles:23)

avg_cycles:23 is the average cycles of this iteration.

Fixes: c4ee06251d ("perf report: Calculate the average cycles of iterations")

Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1546582230-17507-1-git-send-email-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-01-04 12:54:49 -03:00
..
accounting delayacct: track delays from thrashing cache pages 2018-10-26 16:26:32 -07:00
arch tools headers x86: Sync asm/cpufeatures.h copy with the kernel sources 2019-01-04 12:54:49 -03:00
bpf tools: bpftool: fix a bitfield pretty print issue 2018-11-28 16:40:02 -08:00
build perf build: Don't unconditionally link the libbfd feature test to -liberty and -lz 2018-12-21 09:42:46 -03:00
cgroup
crypto crypto: tools - Add cryptostat userspace 2018-09-28 12:46:26 +08:00
firewire
gpio tools gpio: Allow overriding CFLAGS 2018-12-28 16:33:08 -03:00
hv tools: hv: fcopy: set 'error' in case an unknown operation was requested 2018-09-30 08:49:55 -07:00
iio tools iio: Override CFLAGS assignments 2019-01-04 12:54:49 -03:00
include tools headers uapi: Sync copy of asm-generic/unistd.h with the kernel sources 2019-01-04 12:54:49 -03:00
kvm/kvm_stat tools/kvm_stat: switch to python3 2018-11-27 12:53:44 +01:00
laptop
leds
lib Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-26 14:45:18 -08:00
memory-model tools/memory-model: Add more LKMM limitations 2018-10-02 10:28:04 +02:00
nfsd
objtool objtool: Fix segfault in .cold detection with -ffunction-sections 2018-11-20 18:59:00 +01:00
pci tools: PCI: Change pcitest compiling process 2018-10-03 11:19:52 +01:00
pcmcia
perf perf report: Fix wrong iteration count in --branch-history 2019-01-04 12:54:49 -03:00
power perf/core improvements and fixes: 2019-01-03 14:05:16 +01:00
scripts Kbuild: fix # escaping in .cmd files for future Make 2018-04-11 00:03:02 +09:00
spi spi: spidev_test: Improve decoded text part of hex dump 2018-09-04 17:00:37 +01:00
testing Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-12-26 13:07:19 -08:00
thermal/tmon tools thermal tmon: Use -O3 instead of -O1 if available 2019-01-04 12:54:49 -03:00
time
usb usbip: tools: fix atoi() on non-null terminated string 2018-10-18 19:44:39 +02:00
virtio virtio: fix test build after uio.h change 2018-12-19 18:23:49 -05:00
vm tools/vm/page-types.c: fix "defined but not used" warning 2018-09-04 16:45:02 -07:00
wmi
Makefile tools: PCI: Change pcitest compiling process 2018-10-03 11:19:52 +01:00