[Crash-utility] [PATCH] improve the performance of kmem -p

[qiaonuohan]

At 2012-1-16 14:44, qiaonuohan wrote:
> Hello Dave,
> 
> While I am using 'kmem -p', I feel it is too slow, especially with a big
> memory. So I modify something to improve the performance.
> 
> The patch is based on crash 6.0.2, and it has been tested on
> RHEL6.2_x86_64, RHEL6.2_i386, RHEL5.8_x86_64 and RHEL5.8_i386.
> 
> Thanks,
> Qiao Nuohan
> 
> 
> 
> 
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Add the statistics of my test:
1. 100 times of "kmem -p > /dev/null"
	1) 6.0.2:       about 39min
	2) patch added: about 22min

2. 100 times of "kmem -p > ...(disk)"
	1) 6.0.2:       about 145min
	2) patch added: about 26min

I use a buffer to store the output data, replacing too many calls of
'fprintf'. And also decrease the calls of 'mkstring' by making the
format of output data at the beginning.

Thanks,
Qiao Nuohan