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From: Steve Lord <lord@sgi.com>
To: Andrew Morton <akpm@zip.com.au>
Cc: Ben Israel <ben@genesis-one.com>, linux-kernel@vger.kernel.org
Subject: Re: File System Performance
Date: 12 Nov 2001 15:45:02 -0600	[thread overview]
Message-ID: <1005601502.13301.12.camel@jen.americas.sgi.com> (raw)
In-Reply-To: <3BF04289.8FC8B7B7@zip.com.au>
In-Reply-To: <3BF03402.87D44589@zip.com.au>, <3BF02702.34C21E75@zip.com.au>, <00b201c16b81$9d7aaba0$5101a8c0@pbc.adelphia.net> <3BEFF9D1.3CC01AB3@zip.com.au> <00da01c16ba2$96aeda00$5101a8c0@pbc.adelphia.net>  <3BF02702.34C21E75@zip.com.au> <1005595583.13307.5.camel@jen.americas.sgi.com>  <3BF03402.87D44589@zip.com.au> <1005600431.13303.10.camel@jen.americas.sgi.com>  <3BF04289.8FC8B7B7@zip.com.au>

On Mon, 2001-11-12 at 15:43, Andrew Morton wrote:

> 
> It's tar.  It cheats.  It somehow detects that the
> output is /dev/null, and so it doesn't read the input files.
> I think.
> 

Yep it cheats all right:

execve("/bin/tar", ["tar", "cf", "/dev/null", "linux"], [/* 30 vars */])
= 0
% time     seconds  usecs/call     calls    errors syscall
------ ----------- ----------- --------- --------- ----------------
 59.70    1.114097         740      1505           getdents64
 37.22    0.694516          55     12650           lstat64
  1.62    0.030264          39       775         3 open
  0.56    0.010518          14       777           close
  0.40    0.007395          10       770           fstat64
  0.24    0.004553           6       749           fcntl64
  0.11    0.001972         986         2           poll
  0.02    0.000420         210         2         2 connect
  0.02    0.000418          32        13           read
  0.02    0.000345          20        17           old_mmap
  0.02    0.000286          36         8           munmap
  0.02    0.000281          18        16           mmap2
  0.01    0.000189          47         4           socket
  0.01    0.000161          16        10           brk
  0.01    0.000101          51         2           sendto
  0.00    0.000076          15         5           mprotect
  0.00    0.000076          38         2           recvfrom
  0.00    0.000075          25         3           uname
  0.00    0.000059          30         2           readv
  0.00    0.000057          29         2           bind
  0.00    0.000056          28         2           setsockopt
  0.00    0.000039          39         1           readlink
  0.00    0.000025          13         2           getpid
  0.00    0.000023          23         1           rt_sigaction
  0.00    0.000021          21         1           time
  0.00    0.000021          21         1           gettimeofday
  0.00    0.000014           7         2           ioctl
------ ----------- ----------- --------- --------- ----------------
100.00    1.866058                 17324         5 total

Not a lot of reads in there.... I should have known it could
not go that fast.

Steve

-- 

Steve Lord                                      voice: +1-651-683-3511
Principal Engineer, Filesystem Software         email: lord@sgi.com

  parent reply	other threads:[~2001-11-12 21:50 UTC|newest]

Thread overview: 44+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2001-11-12 13:54 Ben Israel
2001-11-12 16:33 ` Andrew Morton
2001-11-12 17:50   ` Ben Israel
2001-11-12 19:46     ` Andrew Morton
2001-11-12 19:59     ` Richard Gooch
2001-11-12 23:07       ` Mike Fedyk
2001-11-13  0:04       ` Richard Gooch
2001-11-13  0:08         ` Mike Fedyk
2001-11-13  0:26         ` Richard Gooch
2001-11-13  0:47           ` Mike Castle
2001-11-13  1:28           ` Mike Fedyk
2001-11-13  6:34           ` Richard Gooch
2001-11-13 20:56             ` Andreas Dilger
2001-11-13  7:45         ` Andreas Dilger
2001-11-12 20:06     ` Steve Lord
2001-11-12 20:41       ` Andrew Morton
2001-11-13  0:17         ` Andreas Dilger
2001-11-13  0:40           ` Peter J . Braam
2001-11-13 20:46             ` Andreas Dilger
2001-11-16 22:07               ` Peter J . Braam
2001-11-16 23:14                 ` Mike Fedyk
2001-11-12 21:27       ` Steve Lord
2001-11-12 21:43         ` Andrew Morton
2001-11-12 21:48           ` Linus Torvalds
2001-11-12 22:11             ` Lionel Bouton
2001-11-12 19:41               ` Gérard Roudier
2001-11-12 22:14               ` Linus Torvalds
2001-11-12 22:30                 ` Ragnar Kjørstad
2001-11-12 22:36                 ` Andrew Morton
2001-11-12 23:04                   ` Mike Castle
2001-11-13  9:56                     ` Peter Wächtler
2001-11-13  9:41                 ` Henning P. Schmiedehausen
2001-11-12 22:16             ` Andrew Morton
2001-11-12 22:32               ` Lionel Bouton
2001-11-12 22:45                 ` Alan Cox
2001-11-12 22:39               ` Alan Cox
2001-11-12 22:39                 ` Xavier Bestel
2001-11-12 22:46               ` Mike Castle
2001-11-12 22:26             ` Steve Lord
2001-11-12 21:45         ` Steve Lord [this message]
2001-11-12 21:53         ` Lionel Bouton
2001-11-12 16:40 ` Ben Israel
2001-11-12 17:29 ` Andrew Morton
2001-11-12 22:36 Grant Erickson

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