Messages in this thread Patch in this message | | | Date | Wed, 29 Jul 2009 07:11:10 -0700 | Subject | Re: Bug in kernel 2.6.31, Slow wb_kupdate writeout | From | Martin Bligh <> |
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> --- mm.orig/fs/fs-writeback.c > +++ mm/fs/fs-writeback.c > @@ -325,7 +325,8 @@ __sync_single_inode(struct inode *inode, > * soon as the queue becomes uncongested. > */ > inode->i_state |= I_DIRTY_PAGES; > - if (wbc->nr_to_write <= 0) { > + if (wbc->nr_to_write <= 0 || > + wbc->encountered_congestion) { > /* > * slice used up: queue for next turn > */ >
That's not sufficient - it only the problem in the wb_kupdate path. If you want to be more conservative, how about we do this?
--- linux-2.6.30/fs/fs-writeback.c.old 2009-07-29 00:08:29.000000000 -0700 +++ linux-2.6.30/fs/fs-writeback.c 2009-07-29 07:08:48.000000000 -0700 @@ -323,43 +323,14 @@ __sync_single_inode(struct inode *inode, * We didn't write back all the pages. nfs_writepages( ) * sometimes bales out without doing anything. Redirty * the inode; Move it from s_io onto s_more_io/s_dirty. + * It may well have just encountered congestion */ - /* - * akpm: if the caller was the kupdate function we put - * this inode at the head of s_dirty so it gets first - * consideration. Otherwise, move it to the tail, for - * the reasons described there. I'm not really sure - * how much sense this makes. Presumably I had a good - * reasons for doing it this way, and I'd rather not - * muck with it at present. - */ - if (wbc->for_kupdate) { - /* - * For the kupdate function we move the inode - * to s_more_io so it will get more writeout as - * soon as the queue becomes uncongested. - */ - inode->i_state |= I_DIRTY_PAGES; - if (wbc->nr_to_write <= 0) { - /* - * slice used up: queue for next turn - */ - requeue_io(inode); - } else { - /* - * somehow blocked: retry later - */ - redirty_tail(inode); - } - } else { - /* - * Otherwise fully redirty the inode so that - * other inodes on this superblock will get som e - * writeout. Otherwise heavy writing to one - * file would indefinitely suspend writeout of - * all the other files. - */ - inode->i_state |= I_DIRTY_PAGES; + inode->i_state |= I_DIRTY_PAGES; + if (wbc->nr_to_write <= 0 || /* sliced used up */ + wbc->encountered_congestion) + requeue_io(inode); + else { + /* somehow blocked: retry later */ redirty_tail(inode); } } else if (inode->i_state & I_DIRTY) { -- 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/
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