On Wed, Jun 05, 2013 at 02:43:28PM +0800, Bob Liu wrote: > Hi Seth, > > On 06/04/2013 04:33 AM, Seth Jennings wrote: > > + /* Couldn't find unbuddied zbud page, create new one */ > > How about moving zswap_is_full() to here. > > if (zswap_is_full()) { > /* Don't alloc any new page, try to reclaim and direct use the > reclaimed page instead */ Yes, this is at the top of the list for improvements. I have already started on this work and it isn't quite as simple as it seems. The difficulty rises from the fact that, for now, zswap uses per-cpu compression buffers which require preemption to be disabled. This prevents the calling zbud_reclaim_page() in zbud_alloc() because the eviction handler for the user may do something that can wait; an allocation with GFP_WAIT for example. So it's going to take some massaging in the zswap layer to get that to work. It's very doable. Just not in this patchset without causing a lot of code thrash. > } > > > + spin_unlock(&pool->lock); > > + page = alloc_page(gfp); > > + if (!page) > > + return -ENOMEM; > > + spin_lock(&pool->lock); > > + pool->pages_nr++; > > + zhdr = init_zbud_page(page); > > + bud = FIRST; <snip> > > It looks good for me except two things. > One is about what the performance might be after the zswap pool is full. > The other is still about the 20% limit of zswap pool size. Yep, working on both of them. Seth -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>