From mboxrd@z Thu Jan 1 00:00:00 1970 In-reply-to: <1193935886.27652.313.camel@twins> (message from Peter Zijlstra on Thu, 01 Nov 2007 17:51:26 +0100) Subject: Re: per-bdi-throttling: synchronous writepage doesn't work correctly References: <1193935886.27652.313.camel@twins> Message-Id: From: Miklos Szeredi Date: Thu, 01 Nov 2007 18:00:47 +0100 Sender: owner-linux-mm@kvack.org Return-Path: To: a.p.zijlstra@chello.nl Cc: jdike@addtoit.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: > > Hi, > > > > It looks like bdi_thresh will always be zero if filesystem does > > synchronous writepage, resulting in very poor write performance. > > > > Hostfs (UML) is one such example, but there might be others. > > > > The only solution I can think of is to add a set_page_writeback(); > > end_page_writeback() pair (or some reduced variant, that only does > > the proportions magic). But that means auditing quite a few > > filesystems... > > Ouch... > > I take it there is no other function that is shared between all these > writeout paths which we could stick a bdi_writeout_inc(bdi) in? No, and you can't detect it from the callers either I think. 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