lkml.org 
[lkml]   [2012]   [Jul]   [5]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] mm: hugetlb: flush dcache before returning zeroed huge page to userspace
On Thu, Jul 05, 2012 at 01:37:46PM +0100, Hillf Danton wrote:
> On Wed, Jul 4, 2012 at 10:32 PM, Will Deacon <will.deacon@arm.com> wrote:
> > When allocating and returning clear huge pages to userspace as a
> > response to a fault, we may zero and return a mapping to a previously
> > dirtied physical region (for example, it may have been written by
> > a private mapping which was freed as a result of an ftruncate on the
> > backing file). On architectures with Harvard caches, this can lead to
> > I/D inconsistency since the zeroed view may not be visible to the
> > instruction stream.
> >
> > This patch solves the problem by flushing the region after allocating
> > and clearing a new huge page. Note that PowerPC avoids this issue by
> > performing the flushing in their clear_user_page implementation to keep
> > the loader happy, however this is closely tied to the semantics of the
> > PG_arch_1 page flag which is architecture-specific.
> >
> > Acked-by: Catalin Marinas <catalin.marinas@arm.com>
> > Signed-off-by: Will Deacon <will.deacon@arm.com>
> > ---
>
> Thanks:)
>
> Acked-by: Hillf Danton <dhillf@gmail.com>

Thanks Hillf. Which tree does this stuff usually go through?

Will


\
 
 \ /
  Last update: 2012-07-05 17:01    [W:0.185 / U:0.908 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site