From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <38620F5A.F4E6301A@idiom.com> Date: Thu, 23 Dec 1999 15:02:34 +0300 From: Hans Reiser MIME-Version: 1.0 Subject: Re: (reiserfs) Re: RFC: Re: journal ports for 2.3? References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: "Benjamin C.R. LaHaise" Cc: Andrea Arcangeli , "Stephen C. Tweedie" , Chris Mason , reiserfs@devlinux.com, linux-fsdevel@vger.rutgers.edu, linux-mm@kvack.org, Ingo Molnar , Linus Torvalds List-ID: "Benjamin C.R. LaHaise" wrote: > I completly agree to change mark_buffer_dirty() to call balance_dirty() > > before returning. But if you add the balance_dirty() calls all over the > > right places all should be _just_ fine as far I can tell. > > I don't agree, both for the reasons above and because doing a > balance_dirty in mark_buffer_dirty tends to result in stalls in the > *wrong* place, because it tends to stall in the middle of an operation, > not before it has begun. You end up stalling on metadata operations that > shouldn't stall. The stall thresholds for data vs metadata have to be > different in order to make the system 'feel' right. This is easily > accomplished by trying to "allocate" the dirty buffers before you actually > dirty them (by checking if there's enough slack in the dirty buffer > margins before doing the operation). > > -ben If reiserfs had good SMP, you could stall it anywhere, and the code could handle that. But we don't, and I bet others also don't, and we won't have it for some time even though we are working on it. Hans -- Get Linux (http://www.kernel.org) plus ReiserFS (http://devlinux.org/namesys). If you sell an OS or internet appliance, buy a port of ReiserFS! If you need customizations and industrial grade support, we sell them. -- 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.nl.linux.org/Linux-MM/