linux/tools
Frederic Weisbecker b965bb4106 perf callchain: Spare double comparison of callchain first entry
When a new callchain child branch matches an existing one in the rbtree,
the comparison of its first entry is performed twice:

1) From append_chain_children() on branch lookup

2) If 1) reports a match, append_chain() then compares all entries of
the new branch against the matching node in the rbtree, and this
comparison includes the first entry of the new branch again.

Lets shortcut this by performing the whole comparison only from
append_chain() which then returns the result of the comparison between
the first entry of the new branch and the iterating node in the rbtree.
If the first entry matches, the lookup on the current level of siblings
stops and propagates to the children of the matching nodes.

This results in less comparisons performed by the CPU.

Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/r/1389713836-13375-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2014-01-17 11:11:01 -03:00
..
cgroup cgroups: fix cgroup_event_listener error handling 2013-01-08 10:00:44 -08:00
firewire tools/firewire: nosy-dump: check for allocation failure 2012-12-02 20:10:18 +01:00
hv Tools: hv: use single send+recv buffer 2013-09-26 12:03:31 -07:00
include tools include: Include <linux/compiler.h> from asm/bug.h 2014-01-13 10:14:13 -03:00
lguest tools/lguest: offer VIRTIO_F_ANY_LAYOUT for net device. 2013-07-15 11:18:32 +09:30
lib tools lib traceevent: Unregister handler when xen plugin is unloaded 2014-01-16 16:26:25 -03:00
net filter: add minimal BPF JIT image disassembler 2013-03-21 11:35:41 -04:00
nfsd NFSD: Added fault injection script 2011-11-07 21:10:47 -05:00
perf perf callchain: Spare double comparison of callchain first entry 2014-01-17 11:11:01 -03:00
power cpupower: Fix segfault due to incorrect getopt_long arugments 2013-12-17 11:29:30 -08:00
scripts tools lib traceevent: Add global QUIET_CC_FPIC build output 2013-12-19 16:18:10 -03:00
testing H8/300 has been dead for several years, the kernel for it has 2013-11-12 14:13:14 +09:00
thermal/tmon tools/thermal: Introduce tmon, a tool for thermal subsystem 2013-11-07 08:45:34 +08:00
usb usb: tools: fix a regression issue that gcc can't link to pthread 2013-12-04 15:10:54 -08:00
virtio virtio_test: verify if virtqueue_kick() succeeded 2013-10-29 11:28:16 +10:30
vm tools/: Convert to new topic libraries 2013-12-16 16:03:27 -03:00
Makefile tools/: Convert to new topic libraries 2013-12-16 16:03:27 -03:00