From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with SMTP id 316906B01F2 for ; Wed, 12 May 2010 13:42:00 -0400 (EDT) Date: Wed, 12 May 2010 13:38:15 -0400 From: Rik van Riel Subject: [PATCH 0/5] always lock the root anon_vma Message-ID: <20100512133815.0d048a86@annuminas.surriel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Andrew Morton Cc: Mel Gorman , Andrea Arcangeli , Minchan Kim , Linux-MM , KAMEZAWA Hiroyuki , LKML , Linus Torvalds List-ID: This patch series implements Linus's suggestion of always locking the root anon_vma. Because the lock in other anon_vmas no longer protects anything at all, we cannot do the "lock dance" that Mel's earlier patches implements and instead need a root pointer in the anon_vma. The only subtlety these patches rely on is that the same_vma list is ordered from new to old, with the root anon_vma at the very end. This, together with the forward list walking in unlink_anon_vmas, ensures that the root anon_vma is the last one freed. The KSM refcount adds some additional complexity, because an anon_vma can stick around after the processes it was attached to have already exited. Patch 5/5 deals with that issue. -- 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-mm.org/ . Don't email: email@kvack.org