Bug 106417

Summary: grep is very slow
Product: [Retired] Red Hat Linux Reporter: Justin Gullingsrud <justin>
Component: grepAssignee: Tim Waugh <twaugh>
Status: CLOSED DUPLICATE QA Contact: Mike McLean <mikem>
Severity: medium Docs Contact:
Priority: medium    
Version: 9   
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Hardware: i686   
OS: Linux   
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Fixed In Version: Doc Type: Bug Fix
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Last Closed: 2006-02-21 18:58:59 UTC Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description Justin Gullingsrud 2003-10-06 22:10:26 UTC 
From Bugzilla Helper:
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Description of problem:
grep runs pathologically slowly on both uniprocessor and smp Intel machines when the file contains many lines with a match on the pattern.   

Version-Release number of selected component (if applicable):
grep-2.5.1-7, kernel-2.4.20-20.9, glibc-2.2.5-34

How reproducible:
Always

Steps to Reproduce:
time grep " " /etc/init.d/functions > /dev/null

Actual Results:  0.14 seconds on a dual 2.4GHz P4.

Expected Results:  0.01 seconds or less, as on RedHat 7.3

Additional info:

This takes 0.68 seconds on a 500 MHz PIII, 0.14 seconds on a dual 2.4 GHz P4.  An Athlon running RedHat 7.3, kernel-2.4.18-10, and glibc-2.2.5-34 does not suffer from this problem.  Using grep-2.5.1-1 has the same problem.  The time scales with file size.
Comment 1 Tim Waugh 2003-10-07 08:32:08 UTC 
Known issue.  See the grep-2.5.1-gofast.patch in the source rpm for how far I
got with it before giving up and reporting it upstream.

*** This bug has been marked as a duplicate of 69900 ***
Comment 2 Red Hat Bugzilla 2006-02-21 18:58:59 UTC 
Changed to 'CLOSED' state since 'RESOLVED' has been deprecated.