Re: [PATCH 00/23] per device dirty throttling -v8

Ingo Molnar
2007-08-04T17:18:00Z

* Diego Calleja <diegocg@gmail.com> wrote:

> El Sat, 4 Aug 2007 18:37:33 +0200, Ingo Molnar <mingo@elte.hu> escribió:
>
> > thousands of applications. So for most file workloads we give
> > Windows a 20%-30% performance edge, for almost nothing. (for
> > RAM-starved kernel builds the performance difference between atime
> > and noatime+nodiratime setups is more on the order of 40%)
>
> Just curious - do you have numbers with relatime?

nope. Stupid question, i just tried it and got this:

EXT3-fs: Unrecognized mount option "relatime" or missing value

i've got util-linux-2.13-0.46.fc6 and 2.6.22 on that box, shouldnt that
be recent enough? As far as i can see it from the kernel-side code, this
works on the general VFS level and hence should be supported by ext3
already.

even relatime means one extra write IO after a file has been created,
but at least for read-mostly files it avoids the continuous atime
update.

Ingo