Messages in this thread | | | From | KOSAKI Motohiro <> | Subject | Re: [patch 3/3][rfc] vmscan: batched swap slot allocation | Date | Tue, 21 Apr 2009 18:41:18 +0900 (JST) |
| |
> On Tue, Apr 21, 2009 at 06:27:08PM +0900, KOSAKI Motohiro wrote: > > > > > - cond_resched(); > > > > > + if (list_empty(&swap_pages)) > > > > > + cond_resched(); > > > > > > > > > Why this ? > > > > > > It shouldn't schedule anymore when it's allocated the first swap slot. > > > Another reclaimer could e.g. sleep on the cond_resched() before the > > > loop and when we schedule while having swap slots allocated, we might > > > continue further allocations multiple slots ahead. > > > > Oops, It seems regression. this cond_resched() intent to > > > > cond_resched(); > > pageout(); > > cond_resched(); > > pageout(); > > cond_resched(); > > pageout(); > > It still does that. While it collects swap pages (swap_pages list is > non-empty), it doesn't page out. And if it restarts for unmap and > page-out, the swap_pages list is empty and cond_resched() is called.
Ah, ok.
| |