Re: Performance issue of 'git branch'

From: Carlos R. Mafra <crmafra2@gmail.com>
Date: Jul 25, 2009, 21:04 UTC
Message-ID: <20090725210407.GA3556@Pilar.aei.mpg.de>
In-Reply-To: <20090725215739.d074e947.tihirvon@gmail.com>

On Sat 25.Jul'09 at 21:57:39 +0300, Timo Hirvonen wrote:

Show 7 quoted lines

> Linus Torvalds <torvalds@linux-foundation.org> wrote:
> 
> > So curl really must die. It may not matter for the expensive operations, 
> > but a lot of scripting is about running all those "cheap" things that just 
> > add up over time.
> 
> SELinux is the problem, not curl.

I don't have SELinux, and without curl it takes ~50% less time (on top of Linus' previous optimizations!).

The time to open() all the libs really sums up to a considerable fraction (when the total time is low, not when compared to the huge 6 secs of before)

Without curl: [mafra@Pilar:linux-2.6]$ grep open strace-nocurl.log |grep lib \

> | awk -F "<" '{print $2}' | sed s/\>// | awk '{s += $1} END {print s}'

0.070104

With curl: [mafra@Pilar:linux-2.6]$ grep open strace-curl.log |grep lib \

> | awk -F "<" '{print $2}' | sed s/\>// | awk '{s += $1} END {print s}'

0.249764

PS: It is interesting that in my laptop the time required
to open libcurl alone is 20x the total time of 'git branch' for Linus'
in his supercomputer:
open("/usr/lib64/libcurl.so.4", O_RDONLY) = 3 <0.066239>