From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 14 May 2001 19:29:28 -0300 (BRT) From: Marcelo Tosatti Subject: Re: [PATCH] v2.4.4-ac9 highmem deadlock In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org Return-Path: To: Ben LaHaise Cc: alan@redhat.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org List-ID: On Mon, 14 May 2001, Ben LaHaise wrote: > Hey folks, Hi. > > The patch below consists of 3 seperate fixes for helping remove the > deadlocks present in current kernels with respect to highmem systems. > Each fix is to a seperate file, so please accept/reject as such. > The third patch (to vmscan.c) adds a SCHED_YIELD to the page launder code > before starting a launder loop. This one needs discussion, but what I'm > attempting to accomplish is that when kswapd is cycling through > page_launder repeatedly, bdflush or some other task submitting io via the > bounce buffers needs to be given a chance to run and complete their io > again. Failure to do so limits the rate of progress under extremely high > load when the vast majority of io will be transferred via bounce buffers. Your patch may allow bdflush or some other task to submit IO if kswapd is looping mad --- but it will not avoid kswapd from eating all the CPU time, which is the _main_ problem. If we avoid kswapd from doing such a thing (which is what we should try to fix in the first place), there is no need for your patch. -- 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.eu.org/Linux-MM/