Messages in this thread | | | Date | Sat, 2 Nov 2002 16:24:19 +0530 | From | Dipankar Sarma <> | Subject | Re: dcache_rcu [performance results] |
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On Sat, Nov 02, 2002 at 11:08:44AM +0100, Andi Kleen wrote: > Dipankar Sarma <woofwoof@hathway.com> writes: > > > > I should add that this is a general trend we see in all workloads > > that do a lot of open/closes and so much so that performance is very > > sensitive to how close to / your application's working directory > > is. You would get much better system time if you compile a kernel > > in /linux as compared to say /home/fs01/users/akpm/kernel/linux ;-) > > That's interesting. Perhaps it would make sense to have a fast path > that just does a string match of the to be looked up path to a cached copy > of cwd and if it matches works as if cwd was the root. Would need to be > careful with chroot where cwd could be outside the root and clear the > cached copy in this case. Then you could avoid all the locking overhead > for directories above your cwd if you stay in there.
Well, on second thoughts I can't see why the path length for pwd would make difference for kernel compilation - it uses relative path and for path lookup, if the first character is not '/', then lookup is done relative to current->fs->pwd. I will do some more benchmarking on and verify.
I did get inputs from Troy Wilson who does specweb measurements that the path name length of the location of the served files make a difference. I presume his webserver setup used full path names.
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