From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Tue, 19 Nov 2002 14:05:30 +0000 (GMT) From: Hugh Dickins Subject: Re: 2.5.48-mm1 In-Reply-To: <3DDA0153.A1971C76@digeo.com> Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: owner-linux-mm@kvack.org Return-Path: To: Andrew Morton Cc: lkml , linux-mm@kvack.org List-ID: On Tue, 19 Nov 2002, Andrew Morton wrote: > > +loop-balance-pages.patch > > Small optimisation to loop I disagree with this one (changing balance_dirty_pages to _ratelimited when loop_thread writes to file): it's a step in the right direction, but I think you should remove that balance_dirty_pages call completely. I'm experimenting with what's needed to prevent deadoralivelock in loop over tmpfs under heavy memory pressure (thank you for eliminating wait_on_page_bit from shrink_list!). One element of that is to ignore balance_dirty_pages below loop (I hadn't noticed the explicit call, offhand I'm unsure whether that's the only possible instance). The loop_thread is working towards undirtying memory (completing writeback): a loop of blk_congestion_waits is appropriate at the upper level where the user task generating dirt needs to be throttled, but I don't believe it's appropriate at this level - we wouldn't want to throttle the disk, no more should we throttle the loop_thread. Hugh -- 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/