2004-01-08 23:56:27

by Daniel McNeil

[permalink] [raw]
Subject: Re: [PATCH linux-2.6.0-test10-mm1] dio-read-race-fix

On Tue, 2003-12-30 at 22:09, Suparna Bhattacharya wrote:

> Since the first filemap_write_and_wait call is redundant and somewhat
> suspect since its called w/o i_sem (I can think of unexpected side effects
> on parallel filemap_write_and_wait calls), have you thought of disabling that
> and then trying to see if you can still recreate the problem ? It may
> not make a difference, but it seems like the right thing to do and could
> at least simplify some of the debugging.
>
> Regards
> Suparna
>


Ok, I retried my test without the filemap_write_and_wait() that is not
protected by i_sem and the test still sees uninitialized data. I'm
still running with test10-mm1 + all the patches I sent out before.
I'm haven't tried 2.6.0-rc*-mm1 yet. I need to move all my debug code
over to the latest mm kernel. I also did not want to change too much
at same time.

Daniel




2004-01-09 03:49:47

by Suparna Bhattacharya

[permalink] [raw]
Subject: Re: [PATCH linux-2.6.0-test10-mm1] dio-read-race-fix

On Thu, Jan 08, 2004 at 03:55:44PM -0800, Daniel McNeil wrote:
> On Tue, 2003-12-30 at 22:09, Suparna Bhattacharya wrote:
>
> > Since the first filemap_write_and_wait call is redundant and somewhat
> > suspect since its called w/o i_sem (I can think of unexpected side effects
> > on parallel filemap_write_and_wait calls), have you thought of disabling that
> > and then trying to see if you can still recreate the problem ? It may
> > not make a difference, but it seems like the right thing to do and could
> > at least simplify some of the debugging.
> >
> > Regards
> > Suparna
> >
>
>
> Ok, I retried my test without the filemap_write_and_wait() that is not
> protected by i_sem and the test still sees uninitialized data. I'm
> still running with test10-mm1 + all the patches I sent out before.
> I'm haven't tried 2.6.0-rc*-mm1 yet. I need to move all my debug code
> over to the latest mm kernel. I also did not want to change too much
> at same time.

Did you have a chance to try akpm's patch for filemap_fdatawait ?
(you should be able to apply it to the same kernel that you are running
with, I think)

Regards
Suparna

>
> Daniel
>
>
>
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--
Suparna Bhattacharya ([email protected])
Linux Technology Center
IBM Software Lab, India