Re: [PATCH] jfs: clear PAGECACHE_TAG_DIRTY for no-write pages

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Fri, Dec 28, 2007 at 12:33:46PM +0100, Peter Zijlstra wrote:
> 
> On Fri, 2007-12-28 at 16:03 +0800, Fengguang Wu wrote:
> > Andrew,
> > 
> > This patch fixed the 'pdflush stuck in D state' bug
> >         http://bugzilla.kernel.org/show_bug.cgi?id=9291
> > and should be pushed to mainline ASAP.
> > ---
> > 
> > When JFS decides to drop a dirty metapage, it simply clears the META_dirty bit
> > and leave alone the PG_dirty and PAGECACHE_TAG_DIRTY bits.
> > 
> > When such no-write page goes to metapage_writepage(), the `relic'
> > PAGECACHE_TAG_DIRTY tag should be cleared, to prevent pdflush from
> > repeatedly trying to sync them.
> > 
> > Also, avoid the redirty when a bio submission is planned.
> > 
> > Tested-by: Markus Rehbach <[email protected]>
> > Signed-off-by: Fengguang Wu <[email protected]> 
> > ---
> 
> > +++ b/fs/jfs/jfs_metapage.c
> 
> > @@ -449,9 +450,15 @@ static int metapage_writepage(struct page *page, struct writeback_control *wbc)
> >  			goto dump_bio;
> >  
> >  		submit_bio(WRITE, bio);
> > -	}
> > -	if (redirty)
> > +	} else if (redirty) {
> >  		redirty_page_for_writepage(wbc, page);
> > +	} else {
> > +		write_lock_irq(&mapping->tree_lock);
> > +		radix_tree_tag_clear(&mapping->page_tree,
> > +				page_index(page),
> > +				PAGECACHE_TAG_DIRTY);
> > +		write_unlock_irq(&mapping->tree_lock);
> > +	}
> 
> I'm not liking this open-coded tag_clear, although I currently fail to
> come up with a nice solution.

Another option is to release/drop such pages ASAP. But what if the
metapage_writepage() is called even before we have the chance to
release it?

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

[Index of Archives]     [Kernel Newbies]     [Netfilter]     [Bugtraq]     [Photo]     [Stuff]     [Gimp]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Video 4 Linux]     [Linux for the blind]     [Linux Resources]
  Powered by Linux