Re: [patch 2/8] mm: write_cache_pages AOP_WRITEPAGE_ACTIVATE fix

[Nick Piggin <nickpiggin@yahoo.com.au>]

On Saturday 11 October 2008 05:29, Hugh Dickins wrote:
> On Fri, 10 Oct 2008, Miklos Szeredi wrote:
> > On Fri, 10 Oct 2008, npiggin@suse.de wrote:
> > > In write_cache_pages, if AOP_WRITEPAGE_ACTIVATE is returned, the
> > > filesystem is calling on us to drop the page lock and retry,
> >
> > Are you sure?  It's not what fs.h says.  I think this return value is
> > related to reclaim (and only used by shmfs), and retrying is not the
> > right thing in that case.

Oh, you're absolutely right about that. Sorry, I confused it with
another AOP flag :( Thanks...


> Only used by shmfs nowadays, yes; it means go away for now,
> don't keep on spamming me with this, but try it again later on.
>
> Though I didn't invent it, it's very much my fault that it
> still exists: I've had a patch to remove it (setting PageActive
> instead, ending that horrid "but in this case, return with the
> page still locked") for about a year, but still hadn't got around
> to verifying that it really does what's intended, before the more
> interesting split-lru changes reached -mm, and I thought it polite
> to hold off for now (though in fact there's almost no conflict).
> I'll get there...

No big deal.