From: Daniel Phillips <phillips@arcor.de>
To: Hugh Dickins <hugh@veritas.com>, "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: <akpm@digeo.com>, <hch@infradead.org>, <linux-mm@kvack.org>,
<linux-kernel@vger.kernel.org>
Subject: Re: [RFC][PATCH] Avoid vmtruncate/mmap-page-fault race
Date: Thu, 29 May 2003 19:15:22 +0200 [thread overview]
Message-ID: <200305291915.22235.phillips@arcor.de> (raw)
In-Reply-To: <Pine.LNX.4.44.0305291723310.1800-100000@localhost.localdomain>
On Thursday 29 May 2003 18:33, you wrote:
> On Thu, 29 May 2003, Paul E. McKenney wrote:
> > On Fri, May 23, 2003 at 11:42:02AM -0700, Paul E. McKenney wrote:
> > > Exactly -- allows a ->nopage() to drop some lock to avoid races
> > > between pagefault and either vmtruncate() or invalidate_mmap_range().
> > > This race (from the cross-host mmap viewpoint) is described in:
> > >
> > > http://marc.theaimsgroup.com/?l=linux-kernel&m=105286345316249&w=2
> >
> > Rediffed for 2.5.70-mm1.
>
> Me? I much preferred your original, much sparer, nopagedone patch
> (labelled "uglyh as hell" by hch).
"me too".
The fat patch that hits every fs to get rid of two lines and .5 cycles per
no_page fault could be an epilogue (if/when it passes muster) to the little
one that does the job and has already been thoroughly tested.
I see both sides of the argument. The third side, not yet discussed, is the
value of doing things incrementally, with widespread testing of the system at
each step.
Regards,
Daniel
WARNING: multiple messages have this Message-ID (diff)
From: Daniel Phillips <phillips@arcor.de>
To: Hugh Dickins <hugh@veritas.com>, "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: akpm@digeo.com, hch@infradead.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: Re: [RFC][PATCH] Avoid vmtruncate/mmap-page-fault race
Date: Thu, 29 May 2003 19:15:22 +0200 [thread overview]
Message-ID: <200305291915.22235.phillips@arcor.de> (raw)
In-Reply-To: <Pine.LNX.4.44.0305291723310.1800-100000@localhost.localdomain>
On Thursday 29 May 2003 18:33, you wrote:
> On Thu, 29 May 2003, Paul E. McKenney wrote:
> > On Fri, May 23, 2003 at 11:42:02AM -0700, Paul E. McKenney wrote:
> > > Exactly -- allows a ->nopage() to drop some lock to avoid races
> > > between pagefault and either vmtruncate() or invalidate_mmap_range().
> > > This race (from the cross-host mmap viewpoint) is described in:
> > >
> > > http://marc.theaimsgroup.com/?l=linux-kernel&m=105286345316249&w=2
> >
> > Rediffed for 2.5.70-mm1.
>
> Me? I much preferred your original, much sparer, nopagedone patch
> (labelled "uglyh as hell" by hch).
"me too".
The fat patch that hits every fs to get rid of two lines and .5 cycles per
no_page fault could be an epilogue (if/when it passes muster) to the little
one that does the job and has already been thoroughly tested.
I see both sides of the argument. The third side, not yet discussed, is the
value of doing things incrementally, with widespread testing of the system at
each step.
Regards,
Daniel
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next prev parent reply other threads:[~2003-05-29 17:02 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-05-23 18:42 [RFC][PATCH] Avoid vmtruncate/mmap-page-fault race Paul E. McKenney
2003-05-23 18:42 ` Paul E. McKenney
2003-05-29 15:14 ` Paul E. McKenney
2003-05-29 15:14 ` Paul E. McKenney
2003-05-29 15:18 ` [RFC][PATCH] Remove LINUX_2_2 Paul E. McKenney
2003-05-29 15:18 ` Paul E. McKenney
2003-05-29 16:33 ` [RFC][PATCH] Avoid vmtruncate/mmap-page-fault race Hugh Dickins
2003-05-29 16:33 ` Hugh Dickins
2003-05-29 17:15 ` Daniel Phillips [this message]
2003-05-29 17:15 ` Daniel Phillips
2003-05-29 17:39 ` Daniel Phillips
2003-05-29 17:39 ` Daniel Phillips
2003-05-29 20:24 ` Paul E. McKenney
2003-05-29 20:24 ` Paul E. McKenney
2003-05-30 2:38 ` Paul E. McKenney
2003-05-30 2:38 ` Paul E. McKenney
-- strict thread matches above, loose matches on Subject: below --
2003-05-17 18:21 [RFC][PATCH] vm_operation to avoid pagefault/inval race Daniel Phillips
2003-05-17 19:49 ` Andrew Morton
2003-05-20 1:23 ` Paul E. McKenney
2003-05-20 8:11 ` Andrew Morton
2003-05-23 14:35 ` [RFC][PATCH] Avoid vmtruncate/mmap-page-fault race Paul E. McKenney
2003-05-23 14:35 ` Paul E. McKenney
2003-05-23 16:21 ` Hugh Dickins
2003-05-23 16:21 ` Hugh Dickins
2003-05-23 17:10 ` Daniel Phillips
2003-05-23 17:10 ` Daniel Phillips
2003-05-23 17:47 ` Hugh Dickins
2003-05-23 17:47 ` Hugh Dickins
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