Be careful with RH 8. 0 if you plan to use it on some heavy workload with some 
scripts...

Thanks,
Hetz

----------  Forwarded Message  ----------

Subject: Where'd the cpu cycles go ?
Date: Monday 04 November 2002 13:30
From: Greg Hosler <[EMAIL PROTECTED]>

Hi,

I just came across a real performance bog in Red Hat 8.0

I noticed one of my sysadmin scripts going painfully slow, and running the
 cpu at 100%. upon some investigation, I noticed that a certain grep
 statement was choking the cpu.

I've generated a shell script which duplicates that particular performance
bog-down, but I can't pinpoint where the cpu's being hogged.

The script generates a file (a.out) a little over a meg big, some 90000
 lines, and then times a grep thru the file.

running this same script on Red Hat 7.3, I see times of (on average) .07
 seconds to run the grep.

On Red Hat 8.0, the same grep takes over 6 and a half minutes (no joke!).
 (i.e. a 4000 times difference, from under a tenth of a second, to almost 400
 seconds)

My first thought was "what happened to grep", so I mounted my RH7.3 /
partition on /mnt/root, and ran /mnt/root/bin/grep, and it also took the long
path, so it's not grep. I ran a quick query in bugzilla (querying description
and/or Summary for "performance", and didn't see anything related.

Can anyone reproduce (or void) my results ?

-Greg

+---------------------------------------------------------------------+
   You can release software that's good, software that's inexpensive, or
   software that's available on time.  You can usually release software
   that has 2 of these 3 attributes -- but not all 3.

| Greg Hosler                                   [EMAIL PROTECTED]    |

+---------------------------------------------------------------------+

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