From: "Ted Ts'o" <tytso@mit.edu>
To: Frederic Weisbecker <fweisbec@gmail.com>
Cc: "Pádraig Brady" <P@draigBrady.com>, linux-kernel@vger.kernel.org
Subject: Re: scheduler / perf stat question about CPU-migrations
Date: Thu, 16 Jun 2011 22:44:25 -0400 [thread overview]
Message-ID: <20110617024425.GE29725@thunk.org> (raw)
In-Reply-To: <20110616151836.GC23624@somewhere.redhat.com>
On Thu, Jun 16, 2011 at 05:18:39PM +0200, Frederic Weisbecker wrote:
> The only solution is too set perf affinity itself:
>
> schedtool -a 1 -e perf stat -- e2fsck -ft /dev/funarg/kbuild
Nope, that doesn't solve the problem:
# schedtool -a 1 -e perf stat -- e2fsck -ft /dev/funarg/kbuild
e2fsck 1.41.14 (22-Dec-2010)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/funarg/kbuild: 223466/1638400 files (0.3% non-contiguous), 4915668/6553600 blocks
Memory used: 2600k/0k (1069k/1532k), time: 6.72/ 1.18/ 0.36
I/O read: 137MB, write: 1MB, rate: 20.38MB/s
Performance counter stats for 'e2fsck -ft /dev/funarg/kbuild':
1523.616797 task-clock # 0.224 CPUs utilized
7227 context-switches # 0.005 M/sec
253 CPU-migrations # 0.000 M/sec
1936 page-faults # 0.001 M/sec
4176409631 cycles # 2.741 GHz
<not counted> stalled-cycles-frontend
<not counted> stalled-cycles-backend
4828485353 instructions # 1.16 insns per cycle
877742160 branches # 576.091 M/sec
8017490 branch-misses # 0.91% of all branches
6.798746204 seconds time elapsed
Note the 253 CPU migration....
- Ted
next prev parent reply other threads:[~2011-06-17 2:44 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-16 14:46 scheduler / perf stat question about CPU-migrations Theodore Ts'o
2011-06-16 15:03 ` Frederic Weisbecker
2011-06-16 15:11 ` Pádraig Brady
2011-06-16 15:18 ` Frederic Weisbecker
2011-06-17 2:44 ` Ted Ts'o [this message]
2011-06-17 5:58 ` David Ahern
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