From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from dax.scot.redhat.com (sct@dax.scot.redhat.com [195.89.149.242]) by kvack.org (8.8.7/8.8.7) with ESMTP id MAA31755 for ; Wed, 20 Jan 1999 12:10:32 -0500 Date: Wed, 20 Jan 1999 17:09:47 GMT Message-Id: <199901201709.RAA11707@dax.scot.redhat.com> From: "Stephen C. Tweedie" MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Subject: Re: Removing swap lockmap... In-Reply-To: References: <871zksqbyq.fsf@atlas.CARNet.hr> Sender: owner-linux-mm@kvack.org To: Andrea Arcangeli Cc: Zlatko Calusic , "Eric W. Biederman" , Linux-MM List , Linux Kernel List List-ID: Hi, On Tue, 19 Jan 1999 19:15:51 +0100 (CET), Andrea Arcangeli said: > On 19 Jan 1999, Zlatko Calusic wrote: >> Yes, this case probably doesn't get enough testing with my current >> setup, so it is quite hard (for me) to prove removing lockmap is >> no-no. Problem is that I don't understand shm swapping very well > Launch some time this proggy to try out shm swapping: I have a shared memory stresser anyway if you want. However, when we originally took out the lock map, it proved _very_ hard to reproduce the race, and only a couple of people reported problems. Plain stress testing with random access patterns over a day or more did not show up the problem. These races can be very nasty and hard to trigger. You really do need to think the change through rather than just try-it-and-see. --Stephen -- This is a majordomo managed list. To unsubscribe, send a message with the body 'unsubscribe linux-mm me@address' to: majordomo@kvack.org