From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <3D767F45.97D8AAC9@zip.com.au> Date: Wed, 04 Sep 2002 14:46:45 -0700 From: Andrew Morton MIME-Version: 1.0 Subject: Re: nonblocking-vm.patch References: <3D767997.B6B76833@zip.com.au> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: "linux-mm@kvack.org" List-ID: Rik van Riel wrote: > > On Wed, 4 Sep 2002, Andrew Morton wrote: > > > > But only if enough IO completes. Otherwise we'll just end > > > up doing too much scanning for no gain again. > > > > Well we want to _find_ the just-completed IO, yes? Which implies > > parking it onto the cold end of the inactive list at interrupt > > time, or a separate list or something. > > In rmap14 I'm doing the following things when scanning the > inactive list: > > 1) if the page was referenced, activate > 2) if the page is clean, reclaim OK. We need to start getting some of that stuff going now. We're way too swappy at present. I'll merge up your NRU/dropbehind patch soon. I imagine that you're waiting for me to stop changing things. > 3) if the page is written to disk, keep it at the end of > the list where we start scanning from hum. With the clustered-writeback-from-the-vm regime, this is done over in mpage_writepages(). And that walks mapping->dirty_pages, and moves the pages to the hot end of the inactive list (if they're already on the inactive list). I suppose we could just move them to the cold end and scan past them, but that's a bit lazy. They could be taken off the LRU altogether and reattached to the cold end at IO completion. But then, very little writeback actually happens from inside shrink_list. > 4) if we don't write the page to disk (I don't submit too > much IO at once) we move it to the far end of the inactive > list > > This means that the pages for which IO completed will be found > somewhere near the start of the list. OK. (Why don't you move them over to inactive_dirty? I've never understood those two lists. I suspect the names are misleading?) -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/