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From: Mel Gorman on 15 Jun 2010 12:00 On Tue, Jun 15, 2010 at 06:47:01AM -0400, Christoph Hellwig wrote: > On Mon, Jun 14, 2010 at 12:17:49PM +0100, Mel Gorman wrote: > > /* > > + * TODO: Try merging with migrations version of putback_lru_pages > > + */ > > +static noinline_for_stack void putback_lru_pages(struct zone *zone, > > + struct zone_reclaim_stat *reclaim_stat, > > + unsigned long nr_anon, unsigned long nr_file, > > + struct list_head *page_list) > > +{ > > I hate to nitpick on this, but with noinline_for_stack a prototype > really is unreadbale unless the function identifier goes to the next > line. Compare the one above with: > > static noinline_for_stack void > putback_lru_pages(struct zone *zone, struct zone_reclaim_stat *reclaim_stat, > unsigned long nr_anon, unsigned long nr_file, > struct list_head *page_list) > > > -static unsigned long shrink_inactive_list(unsigned long nr_to_scan, > > +static noinline_for_stack unsigned long shrink_inactive_list(unsigned long nr_to_scan, > > struct zone *zone, struct scan_control *sc, > > int priority, int file) > > Same here, just even worse due to the spill over ove 80 characters. > It's a fair nitpick and so is cleaned up. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
From: Mel Gorman on 17 Jun 2010 06:40
On Wed, Jun 16, 2010 at 04:43:09PM -0700, Andrew Morton wrote: > On Mon, 14 Jun 2010 12:17:49 +0100 > Mel Gorman <mel(a)csn.ul.ie> wrote: > > > shrink_inactive_list() sets up a pagevec to release unfreeable pages. It > > uses significant amounts of stack doing this. This patch splits > > shrink_inactive_list() to take the stack usage out of the main path so > > that callers to writepage() do not contain an unused pagevec on the > > stack. > > You can get the entire pagevec off the stack - just make it a > static-to-shrink_inactive_list() pagevec-per-cpu. > That idea has been floated as well. I didn't pursue it because Dave said that giving page reclaim a stack diet was never going to be the full solution so I didn't think the complexity was justified. I kept some of the stack reduction stuff because a) it was there and b) it would give kswapd extra headroom when calling writepage. > Locking just requires pinning to a CPU. We could trivially co-opt > shrink_inactive_list()'s spin_lock_irq() for that, but > pagevec_release() can be relatively expensive so it'd be sad to move > that inside spin_lock_irq(). It'd be better to slap a > get_cpu()/put_cpu() around the whole thing. > It'd be something interesting to try out when nothing else was happening but I'm not going to focus on it for the moment unless I think it will really help this stack overflow problem. -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |