On 07/31/2007 01:11 PM, richard kennedy wrote: Peter, did you see this?
> exit loop in balance_dirty_pages when no more pages available to write > > On a bdi that has very little traffic balance_dirty_pages can loop > needlessly waiting until do_writepages has written enough pages. > > do_writepages will return encountered_congestion==0 && nr_to_write > 0 > when it has completed a pass but did not find enough pages available to > write. balance_dirty_pages ignores this and keeps looping until a total > of chunk pages was written. > > this patch adds an extra exit condition to break out of the loop in this > case. > > I've tested this on my amd64 desktop, and I also have a version of this > patch that includes a printk and a test case that occasionally does > trigger this condition. > > Signed-off-by: Richard Kennedy <[EMAIL PROTECTED]> > > ------ > --- linux-2.6.22.1/mm/page-writeback.c.orig 2007-07-30 16:36:09.000000000 > +0100 > +++ linux-2.6.22.1/mm/page-writeback.c 2007-07-31 16:26:43.000000000 > +0100 > @@ -250,6 +250,8 @@ static void balance_dirty_pages(struct a > pages_written += write_chunk - wbc.nr_to_write; > if (pages_written >= write_chunk) > break; /* We've done our duty */ > + if (!wbc.encountered_congestion && wbc.nr_to_write > 0) > + break; /* didn't find enough to do */ > } > congestion_wait(WRITE, HZ/10); > } > - 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/
