From mboxrd@z Thu Jan 1 00:00:00 1970 In-reply-to: <1195155759.22457.29.camel@lappy> (message from Peter Zijlstra on Thu, 15 Nov 2007 20:42:38 +0100) Subject: Re: [RFC] fuse writable mmap design References: <1195154530.22457.16.camel@lappy> <1195155759.22457.29.camel@lappy> Message-Id: From: Miklos Szeredi Date: Thu, 15 Nov 2007 20:57:16 +0100 Sender: owner-linux-mm@kvack.org Return-Path: To: a.p.zijlstra@chello.nl Cc: miklos@szeredi.hu, linux-kernel@vger.kernel.org, akpm@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-mm@kvack.org List-ID: > The next point then, I'd expect your fuse_page_mkwrite() to push > writeout of your 32-odd mmap pages instead of poll. You're talking about this: + wait_event(fc->writeback_waitq, + fc->numwrite < FUSE_WRITEBACK_THRESHOLD); right? It's one of the things I need to clean out, there's no point in fc->numwrite, which is essentially the same as the BDI_WRITEBACK counter. OTOH, I'm thinking about adding a per-fs limit (adjustable for privileged mounts) of dirty+writeback. I'm not sure how hard would it be to add support for this into balance_dirty_pages(). So I'm thinking of a parameter in struct backing_dev_info that is used to clip the calculated per-bdi threshold below this maximum. How would that affect the proportions algorithm? What would happen to the unused portion? Would it adapt to the slowed writeback and allocate it to some other writer? Miklos -- 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/ . Don't email: email@kvack.org