From: James Bottomley <James.Bottomley@HansenPartnership.com>
To: John David Anglin <dave.anglin@nrc-cnrc.gc.ca>
Cc: linux-parisc@vger.kernel.org, Helge Deller <deller@gmx.de>
Subject: Re: Patch for segfaults in minifail tests
Date: Fri, 30 Apr 2010 16:13:44 -0500 [thread overview]
Message-ID: <1272662024.2844.44.camel@mulgrave.site> (raw)
In-Reply-To: <20100430211136.GA11644@hiauly1.hia.nrc.ca>
On Fri, 2010-04-30 at 17:11 -0400, John David Anglin wrote:
> On Fri, 30 Apr 2010, James Bottomley wrote:
>
> > It's the essential patch we need to fix up our kmapping. Right at the
> > moment kmap of a page with a dirty cache line in userspace sees stale
> > data and kunmap of a page the kernel has modified will see likewise.
>
> Did you try using the version of copy_user_page_asm that uses
> equivalent aliasing? There is an issue with needing cache flushing
> noted in pgtable.h, but if this works it may be less of a hammer.
Not yet. I want to isolate the root cause first before I start adding
optimisations. Although the optimisation is a fairly safe one, since
it's used by a lot of other architectures.
James
next prev parent reply other threads:[~2010-04-30 21:13 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-04-30 18:21 Patch for segfaults in minifail tests James Bottomley
2010-04-30 21:11 ` John David Anglin
2010-04-30 21:13 ` James Bottomley [this message]
2010-05-01 18:29 ` Thibaut VARENE
2010-05-01 22:25 ` Helge Deller
2010-05-01 23:13 ` John David Anglin
2010-05-01 23:39 ` James Bottomley
2010-05-03 21:54 ` John David Anglin
2010-05-01 23:40 ` Thibaut VARÈNE
2010-05-02 8:19 ` Helge Deller
2010-05-02 10:59 ` Thibaut VARÈNE
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