From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Stephen C. Tweedie" MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <14199.62047.543601.273526@dukat.scot.redhat.com> Date: Mon, 28 Jun 1999 23:08:31 +0100 (BST) Subject: Re: filecache/swapcache questions [RFC] [RFT] [PATCH] kanoj-mm12-2.3.8 In-Reply-To: <199906282051.NAA12151@google.engr.sgi.com> References: <199906282051.NAA12151@google.engr.sgi.com> Sender: owner-linux-mm@kvack.org Return-Path: To: Kanoj Sarcar Cc: Chuck Lever , andrea@suse.de, torvalds@transmeta.com, sct@redhat.com, linux-mm@kvack.org List-ID: Hi, On Mon, 28 Jun 1999 13:51:03 -0700 (PDT), kanoj@google.engr.sgi.com (Kanoj Sarcar) said: >> or perhaps the kernel could start more than one kswapd (one per swap >> partition?). with my patch, regular processes never wait for swap out >> I/O, only kswapd does. This is a mistake: such blocking is one of the prime ways in which we can limit the rate at which processes can consume memory. > Oh no, I was not talking about exotic stuff like RT ... I was > simply pointing out that to prevent deadlocks, and guarantee forward > progress, you have to show that despite what underlying fs/driver > code does, at least one memory freer is free to do its job. Yep, which is why we have a separate kpiod right now: it guarantees that potential recursive fs locking stalls get shifted from kswapd to a separate thread to make sure that kswapd can always make progress. --Stephen -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://humbolt.geo.uu.nl/Linux-MM/