Messages in this thread | | | Date | Thu, 16 Jun 2011 22:44:25 -0400 | From | Ted Ts'o <> | Subject | Re: scheduler / perf stat question about CPU-migrations |
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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
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