[Lustre-devel] [PATCH] Fix task IO accounting on reads

Mark Hills Mark.Hills at framestore.com
Tue Jul 19 09:08:08 PDT 2011

On Tue, 19 Jul 2011, Richard Henwood wrote:

> On Tue, Apr 26, 2011 at 11:06 AM, Mark Hills <Mark.Hills at framestore.com> wrote:
> > We've often found it inconvenient that reads from Lustre mounts do not
> > correctly increment IO counts (/proc/<pid>/io).
> >
> > Below is a patch which aims to fix this functionality.
> >
> > The symptom is that writes are accounted for, but not reads. It seems that
> > the accounting it normally done in the kernels page writeback and
> > readahead functionality. Therefore as Lustre implements its own readahead,
> > it must also maintain its own accounting on reads (but not writes).
> >
> Hi Mark;
> Are you aware of the (soon to land) patch:
> Lustre client procfs stats: read_bytes does not record the number of
> bytes transfered from the fs:
> http://jira.whamcloud.com/browse/LU-333

I was aware of these stats (and this patch), but I concluded that they did 
not track memory mapped access.

So I think our patches address two separate parts of the process. But I'm 
happy to be corrected -- it was some time ago that I did this.


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