From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id E6C846B0012 for ; Wed, 18 May 2011 16:25:54 -0400 (EDT) Date: Wed, 18 May 2011 13:25:47 -0700 From: Andrew Morton Subject: Re: [PATCH 1/4] VM/RMAP: Add infrastructure for batching the rmap chain locking v2 Message-Id: <20110518132547.24d665e1.akpm@linux-foundation.org> In-Reply-To: <1305330384-19540-2-git-send-email-andi@firstfloor.org> References: <1305330384-19540-1-git-send-email-andi@firstfloor.org> <1305330384-19540-2-git-send-email-andi@firstfloor.org> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andi Kleen Cc: linux-mm@kvack.org, Andi Kleen , Andrea Arcangeli On Fri, 13 May 2011 16:46:21 -0700 Andi Kleen wrote: > In fork and exit it's quite common to take same rmap chain locks > again and again when the whole address space is processed for a > address space that has a lot of sharing. Also since the locking > has changed to always lock the root anon_vma this can be very > contended. > > This patch adds a simple wrapper to batch these lock acquisitions > and only reaquire the lock when another is needed. The main > advantage is that when multiple processes are doing this in > parallel they will avoid a lot of communication overhead > on the lock cache line. > > v2: Address review feedback. Drop lockbreak. Rename init function. Doesn't compile: include/linux/rmap.h: In function 'anon_vma_unlock_batch': include/linux/rmap.h:146: error: 'struct anon_vma' has no member named 'lock' mm/rmap.c: In function '__anon_vma_lock_batch': mm/rmap.c:1737: error: 'struct anon_vma' has no member named 'lock' mm/rmap.c:1739: error: 'struct anon_vma' has no member named 'lock' I think I reported this against the v1 patches. Please fix up the checkpatch errors? -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org