From: "K.Prasad" <prasad@linux.vnet.ibm.com>
To: Ingo Molnar <mingo@elte.hu>, Frederic Weisbecker <fweisbec@gmail.com>
Cc: LKML <linux-kernel@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Alan Stern <stern@rowland.harvard.edu>,
Andrew Morton <akpm@linux-foundation.org>,
Paul Mackerras <paulus@samba.org>
Subject: [RFC Patch 0/4] Enhance perf-events to profile memory accesses using hw-breakpoints - ver II
Date: Wed, 28 Oct 2009 21:28:27 +0530 [thread overview]
Message-ID: <20091028155827.GA8604@in.ibm.com> (raw)
Hi All,
Please find version II of the patchset that enables perf-events to
place hw-breakpoints over kernel symbols (along with requisite enhancements to
the hw-breakpoint layer).
Changelog version II
---------------------
Version I: http://lkml.org/lkml/2009/10/26/461
- Fixed parsing issues that disallowed other perf events to be invoked
- Fixed user-space breakpoint usage which was broken due to patch 2/4
- Introduced an instance of perf_sample_data for use by do_perf_sw_event()
An edited log of 'perf stat' and 'perf record' output is shown below for your
reference.
Kindly let me know your suggestions/feedback about the same.
Thanks,
K.Prasad
Screen logs
------------
# perf stat -v -i -e breakpoint-readwrite:pid_max -e breakpoint-write:jiffies make kernel/futex.o
CHK include/linux/version.h
CHK include/linux/utsrelease.h
SYMLINK include/asm -> include/asm-x86
CALL scripts/checksyscalls.sh
CC kernel/futex.o
breakpoint-readwrite: 68 298512531 298512531
breakpoint-write: 235 298512531 298512531
Performance counter stats for 'make kernel/futex.o':
68 breakpoint-readwrite # 0.000 M/sec
235 breakpoint-write # 0.000 M/sec
14.571235288 seconds time elapsed
#
#
# perf record -v -i -e breakpoint-readwrite:jiffies top
[Ran 'top' for about 10 seconds]
# perf report -i perf.data
# Samples: 2022950155
#
# Overhead Command Shared Object Symbol
# ........ ....... ............. ......
#
99.99% top [kernel] [k] scheduler_tick
0.01% perf [kernel] [k] scheduler_tick
0.00% top [kernel] [k] set_track
0.00% top [kernel] [k] run_timer_softirq
0.00% perf [kernel] [k] set_track
0.00% top [kernel] [k] __call_rcu
0.00% top [kernel] [k] calc_global_load
0.00% top [kernel] [k] do_timer
0.00% top [kernel] [k] __rcu_process_callbacks
#
# (For a higher level overview, try: perf report --sort comm,dso)
#
next reply other threads:[~2009-10-28 15:58 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-28 15:58 K.Prasad [this message]
2009-10-29 8:19 ` [RFC Patch 0/4] Enhance perf-events to profile memory accesses using hw-breakpoints - ver II Ingo Molnar
2009-10-29 22:24 ` K.Prasad
2009-10-31 16:19 ` Frederic Weisbecker
2009-11-02 15:05 ` Ingo Molnar
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