From mboxrd@z Thu Jan 1 00:00:00 1970 In-reply-to: <1193942132.27652.331.camel@twins> (message from Peter Zijlstra on Thu, 01 Nov 2007 19:35:32 +0100) Subject: Re: per-bdi-throttling: synchronous writepage doesn't work correctly References: <1193935886.27652.313.camel@twins> <1193936949.27652.321.camel@twins> <1193937408.27652.326.camel@twins> <1193942132.27652.331.camel@twins> Message-Id: From: Miklos Szeredi Date: Thu, 01 Nov 2007 20:19:45 +0100 Sender: owner-linux-mm@kvack.org Return-Path: To: peterz@infradead.org Cc: jdike@addtoit.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, hch@infradead.org, akpm@linux-foundation.org, viro@zeniv.linux.org.uk List-ID: > > > > See the file "Locking" for more details. > > > > > > The "should set PG_Writeback" bit threw me off I guess. > > Hmm, set_page_writeback() is also the one clearing the radix tree dirty > tag. So if that is not called, we get in a bit of a mess, no? > > Which makes me think hostfs is buggy. Yes, looks like that sort of usage is not valid. But not clearing the dirty tag won't cause any malfunction, it'll just waste some CPU when looking for dirty pages to write back. This is probably why this wasn't noticed earlier. 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