grep -r speed fc2 vs. rh 6.1

[Gene Smith]

Tim Waugh wrote, On 12/19/2004 05:40 AM:
> On Sun, Dec 19, 2004 at 01:13:49AM -0500, Gene Smith wrote:
> 
> 
>>I have the same huge source tree on fc2 500Mhz Athlon with IDE drive and 
>>on a old hp vectra 200Mhz with Pentium pro and scsi drive running rh 6.1 
>>with ext2. A "grep -r" for the same string on the vectra takes about 
>>about a third as long to return results as compared to the somewhat 
>>"faster" Athlon/IDE/ext3 system running fc2. However, building the tree 
>>(and most everything else) takes longer on the vectra by a noticeable 
>>amount.
>>
>>Both are running grep from a kde "konsole" in their respective kde 
>>environments. Is it possible that fc2 gives grep and possibly similar 
>>commands a lower priority than rh 6.1 gives? Or is it the scsi drives or 
>>ext2 (on rh 6.1) vs IDE and ext3 I am using on fc2?
> 
> 
> Try the grep package from FC3 updates -- I think it should work okay
> on FC2 as well.

Upgraded to grep-2.5.1-31.i386.rpm from a FC3 mirror and see no 
improvement on my FC2 system.

> 
> It'll be because you're running in a non-C locale, and so grep is
> obliged to perform more work to get locale sorting order correct.  The
> efficiency for UTF-8 processing has been improved in the FC3 updates
> package.

As C. Simpson suggested, setting env LC_ALL=C speeds it up so it is 
faster than the old vectra with rh6. Is there any downside to just 
setting "export LC_ALL=C" in ~/.bash_profile ?

For the record, here is the speeds I am seeing on FC2 (with either grep 
version) searching the same tree for the same string (with no changes to 
.bash_profile):

With "env FC_ALL=C grep -r my_string ." : 25-30 seconds
With "grep -r my_string ."              : 2min 15seconds.