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authorFrederic Weisbecker <fweisbec@gmail.com>2009-11-23 15:42:35 +0100
committerIngo Molnar <mingo@elte.hu>2009-11-23 18:18:31 +0100
commit1b290d670ffa883b7e062177463a8efd00eaa2c1 (patch)
treed6449227ae19be6fb9046ac5d12cc3ae9d252972 /tools/perf/Documentation
parentf5ffe02e5046003ae7e2ce70d3d1c2a73331268b (diff)
perf tools: Add support for breakpoint events in perf tools
Add the breakpoint events support with this new sysnopsis: mem:addr[:access] Where addr is a raw addr value in the kernel and access can be either [r][w][x] Example to profile tasklist_lock: $ grep tasklist_lock /proc/kallsyms ffffffff8189c000 D tasklist_lock $ perf record -e mem:0xffffffff8189c000:rw -a -f -c 1 $ perf report # Samples: 62 # # Overhead Command Shared Object Symbol # ........ ............... ............. ...... # 29.03% swapper [kernel] [k] _raw_read_trylock 29.03% swapper [kernel] [k] _raw_read_unlock 19.35% init [kernel] [k] _raw_read_trylock 19.35% init [kernel] [k] _raw_read_unlock 1.61% events/0 [kernel] [k] _raw_read_trylock 1.61% events/0 [kernel] [k] _raw_read_unlock Coming soon: - Support for symbols in the event definition. - Default period to 1 for breakpoint events because these are not high frequency events. The same thing is needed for trace events. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Prasad <prasad@linux.vnet.ibm.com> LKML-Reference: <1258987355-8751-4-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Prasad <prasad@linux.vnet.ibm.com>
Diffstat (limited to 'tools/perf/Documentation')
-rw-r--r--tools/perf/Documentation/perf-record.txt16
1 files changed, 12 insertions, 4 deletions
diff --git a/tools/perf/Documentation/perf-record.txt b/tools/perf/Documentation/perf-record.txt
index 0ff23de9e45..fc46c0b40f6 100644
--- a/tools/perf/Documentation/perf-record.txt
+++ b/tools/perf/Documentation/perf-record.txt
@@ -26,11 +26,19 @@ OPTIONS
-e::
--event=::
- Select the PMU event. Selection can be a symbolic event name
- (use 'perf list' to list all events) or a raw PMU
- event (eventsel+umask) in the form of rNNN where NNN is a
- hexadecimal event descriptor.
+ Select the PMU event. Selection can be:
+ - a symbolic event name (use 'perf list' to list all events)
+
+ - a raw PMU event (eventsel+umask) in the form of rNNN where NNN is a
+ hexadecimal event descriptor.
+
+ - a hardware breakpoint event in the form of '\mem:addr[:access]'
+ where addr is the address in memory you want to break in.
+ Access is the memory access type (read, write, execute) it can
+ be passed as follows: '\mem:addr[:[r][w][x]]'.
+ If you want to profile read-write accesses in 0x1000, just set
+ 'mem:0x1000:rw'.
-a::
System-wide collection.