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From: "Martin A. Fink" <fink@mpe.mpg.de>
To: linux-kernel@vger.kernel.org
Subject: Re: SATA-performance: Linux vs. FreeBSD
Date: Mon, 12 Feb 2007 17:37:12 +0100	[thread overview]
Message-ID: <200702121737.12882.fink@mpe.mpg.de> (raw)
In-Reply-To: <p73abzji9xi.fsf@bingen.suse.de>

Some more info:

:~> strace -c -T -o trace.out dd if=/dev/zero of=test.txt bs=10MB count=200

200+0 Datensätze ein
200+0 Datensätze aus
2000000000 bytes (2,0 GB) copied, 52,8632 seconds, 37,8 MB/s

test.txt:

% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 93.26    6.845265       33555       204           write
  6.41    0.470283       11757        40        18 open
  0.32    0.023687         116       205           read
  0.00    0.000149           9        16           mmap2
  0.00    0.000119          40         3           munmap
  0.00    0.000081           3        24           close
  0.00    0.000068           6        11           old_mmap
  0.00    0.000064           3        20           fstat64
  0.00    0.000040           4        10           rt_sigaction
  0.00    0.000036          12         3           madvise
  0.00    0.000014           7         2           clock_gettime
  0.00    0.000010           3         3           brk
  0.00    0.000008           8         1           _sysctl
  0.00    0.000007           7         1         1 access
  0.00    0.000006           6         1           mprotect
  0.00    0.000005           5         1           futex
  0.00    0.000004           4         1           uname
  0.00    0.000004           4         1           _llseek
  0.00    0.000003           3         1           rt_sigprocmask
  0.00    0.000003           3         1           getrlimit
  0.00    0.000003           3         1           set_thread_area
  0.00    0.000003           3         1           set_tid_address
------ ----------- ----------- --------- --------- ----------------
100.00    7.339862                   551        19 total

This means, that the CPU is only 7.3 of 52.8 seconds working. This is what one 
can hear: If I run programs where the time they need is the same time as 
strace says, then I have 100% CPU load and the cpu fan starts to blow 
heavily. In the case here, the heat fan does not do anything. It looks like 
the SATA driver simply blocks the CPU while doing whatever...

  parent reply	other threads:[~2007-02-12 16:37 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-02-12 14:02 SATA-performance: Linux vs. FreeBSD Martin A. Fink
2007-02-12 17:04 ` Andi Kleen
2007-02-12 16:27   ` Martin A. Fink
2007-02-12 18:41     ` Andi Kleen
2007-02-12 17:56       ` Martin A. Fink
2007-02-12 18:17         ` Ray Lee
2007-02-12 19:08         ` Alan
2007-02-12 20:34           ` Nigel Cunningham
2007-02-13  9:34           ` Martin A. Fink
2007-02-13 11:25             ` Alan
2007-02-13 12:32               ` Martin A. Fink
2007-02-13 14:47                 ` Theodore Tso
2007-02-13 15:03                   ` Alan
2007-02-13 17:12               ` Jeff Garzik
2007-02-12 23:31         ` Matthias Schniedermeyer
2007-02-13  9:25           ` Martin A. Fink
2007-02-13 10:08             ` Arjan van de Ven
2007-02-13 11:18               ` Andi Kleen
2007-02-13 10:25                 ` Arjan van de Ven
2007-02-13 11:27               ` Alan
2007-02-13 11:59                 ` Jörn Engel
2007-02-13 19:54               ` Jeffrey Hundstad
2007-02-13 10:16             ` Matthias Schniedermeyer
2007-02-13 10:29               ` Martin A. Fink
2007-02-13 12:04                 ` Jörn Engel
2007-02-13 12:24                 ` Matthias Schniedermeyer
2007-02-13 12:49                   ` Martin A. Fink
2007-02-13 13:53                     ` Matthias Schniedermeyer
2007-02-12 16:37   ` Martin A. Fink [this message]
2007-02-12 18:19     ` Stefan Richter
2007-02-13 19:09     ` Jeff Carr
2007-02-12 17:42   ` Martin A. Fink
2007-02-15  5:48 ` Tejun Heo

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