lkml.org 
[lkml]   [2007]   [Feb]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [rfc][patch 0/3] a faster buffered write deadlock fix?
On Fri, 9 Feb 2007 10:54:05 +0100 Nick Piggin <npiggin@suse.de> wrote:

> On Fri, Feb 09, 2007 at 12:41:01AM -0800, Andrew Morton wrote:
> > On Thu, 8 Feb 2007 14:07:15 +0100 (CET) Nick Piggin <npiggin@suse.de> wrote:
> >
> > > So I have finally finished a first slightly-working draft of my new aops
> > > op (perform_write) proposal. I would be interested to hear comments about
> > > it. Most of my issues and concerns are in the patch headers themselves,
> > > so reply to them.
> > >
> > > The patches are against my latest buffered-write-fix patchset.
> >
> > What happened with Linus's proposal to instantiate the page as pinned,
> > non-uptodate, unlocked and in pagecache while we poke the user address?
>
> That's still got a deadlock,

It does?

> and also it doesn't work if we want to lock
> the page when performing a minor fault (which I want to fix fault vs
> invalidate),

It's hard to discuss this without a description of what you want to fix
there, and a description of how you plan to fix it.

> and also assumes nobody's ->nopage locks the page or
> requires any resources that are held by prepare_write (something not
> immediately clear to me with the cluster filesystems, at least).

The nopage handler is filemap_nopage(). Are there any exceptions to that?

> But that all becomes legacy path, so do we really care? Supposing fs
> maintainers like perform_write, then after the main ones have implementations
> we could switch over to the slow-but-correct prepare_write legacy path.
> Or we could leave it, or we could use Linus's slightly-less-buggy scheme...
> by that point I expect I'd be sick of arguing about it ;)

It's worth "arguing" about. This is write(). What matters more??
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-02-09 11:15    [W:0.123 / U:2.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site