Messages in this thread | | | Subject | Re: vm_ops.page_mkwrite() fails with vmalloc on 2.6.23 | From | Peter Zijlstra <> | Date | Mon, 29 Oct 2007 18:01:42 +0100 |
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On Mon, 2007-10-29 at 01:17 -0700, Jaya Kumar wrote: > On 10/29/07, Andrew Morton <akpm@linux-foundation.org> wrote: > > On Mon, 22 Oct 2007 16:40:57 +0200 Stefani Seibold <stefani@seibold.net> wrote: > > > > > > The problem original occurs with the fb_defio driver (driver/video/fb_defio.c). > > > This driver use the vm_ops.page_mkwrite() handler for tracking the modified pages, > > > which will be in an extra thread handled, to perform the IO and clean and > > > write protect all pages with page_clean(). > > >
> An aside, I just tested that deferred IO works fine on 2.6.22.10/pxa255. > > I understood from the thread that PeterZ is looking into page_mkclean > changes which I guess went into 2.6.23. I'm also happy to help in any > way if the way we're doing fb_defio needs to change.
OK, seems I can't read. Or at least, I missed a large part of the problem.
page_mkclean() hasn't changed, it was ->page_mkwrite() that changed. And looking at the fb_defio code, I'm not sure I understand how its page_mkclean() use could ever have worked.
The proposed patch [1] only fixes the issue of ->page_mkwrite() on vmalloc()'ed memory. Not page_mkclean(), and that has never worked from what I can make of it.
Jaya, could you shed some light on this? I presume you had your display working.
[1] which I will clean up and resend after this issue is cleared up - and preferably tested by someone who has this hardware.
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