From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from neon.transmeta.com (neon-best.transmeta.com [206.184.214.10]) by kvack.org (8.8.7/8.8.7) with ESMTP id TAA13165 for ; Thu, 28 Jan 1999 19:26:48 -0500 Date: Thu, 28 Jan 1999 16:17:42 -0800 (PST) From: Linus Torvalds Subject: Re: [patch] fixed both processes in D state and the /proc/ oopses [Re: [patch] Fixed the race that was oopsing Linux-2.2.0] In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Andrea Arcangeli Cc: "Stephen C. Tweedie" , linux-kernel@vger.rutgers.edu, werner@suse.de, mlord@pobox.com, "David S. Miller" , gandalf@szene.CH, adamk@3net.net.pl, kiracofe.8@osu.edu, ksi@ksi-linux.COM, djf-lists@ic.NET, tomh@taz.ccs.fau.edu, Alan Cox , linux-mm@kvack.org List-ID: On Thu, 28 Jan 1999, Andrea Arcangeli wrote: > > If you remove the kernel lock around do_exit() you _need_ my mm_lock > spinlock. You need it to make atomic the decreasing of mm->count and > current->mm = &init_mm. If the two instructions are not atomic you have > _no_ way to know if you can mmget() at any time the mm of a process. Andrea, just go away. The two do not _have_ to be atomic, they never had to, and they never _will_ have to be atomic. You obviously haven't read all my email explaining why they don't have to be atomic. > I repeat in another way (just trying to avoid English mistakes): > decreasing mm->count has to go in sync with updating current->mm, No it has not. Linus -- To unsubscribe, send a message with 'unsubscribe linux-mm my@address' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://humbolt.geo.uu.nl/Linux-MM/