From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Morton Date: Thu, 13 May 2010 19:24:36 +0000 Subject: Re: [PATCH] fb_defio: fix for non-dirty ptes Message-Id: <20100513122436.e69af046.akpm@linux-foundation.org> List-Id: References: <1273697505-23421-1-git-send-email-albert_herranz@yahoo.es> In-Reply-To: <1273697505-23421-1-git-send-email-albert_herranz@yahoo.es> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-fbdev@vger.kernel.org On Thu, 13 May 2010 07:34:11 +0800 Jaya Kumar wrote: > On Thu, May 13, 2010 at 4:51 AM, Albert Herranz wrote: > > This patch fixes a problem observed while using fb_defio with a short > > delay on a PowerPC platform. > > > > It is possible that page_mkclean() is invoked in the deferred io work > > function _before_ a PTE has been marked dirty. In this case, the page > > is removed from the defio pagelist but page_mkclean() does not > > write-protect the page again. The end result is that defio ignores all > > subsequent writes to the page and the corresponding portions of the > > framebuffer never get updated. > > > > The fix consists in keeping track of the pages with non-dirty PTEs, > > re-checking them again on the next deferred io work iteration. > > Note that those pages are not passed to the defio callback as they are > > not written by userspace yet. > > > > Signed-off-by: Albert Herranz > > Looks good to me. Thanks for the bugfix. > > Acked-by: Jaya Kumar For some reason my linux-fbdev feed is being stupid and I don't have a copy of the patch. Resend, please?