From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Sun, 22 Apr 2007 01:18:10 -0700 From: Andrew Morton Subject: Re: [PATCH] lazy freeing of memory through MADV_FREE Message-Id: <20070422011810.e76685cc.akpm@linux-foundation.org> In-Reply-To: <46247427.6000902@redhat.com> References: <46247427.6000902@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Rik van Riel Cc: linux-kernel , linux-mm , "David S. Miller" List-ID: On Tue, 17 Apr 2007 03:15:51 -0400 Rik van Riel wrote: > Make it possible for applications to have the kernel free memory > lazily. This reduces a repeated free/malloc cycle from freeing > pages and allocating them, to just marking them freeable. If the > application wants to reuse them before the kernel needs the memory, > not even a page fault will happen. > > This patch, together with Ulrich's glibc change, increases > MySQL sysbench performance by a factor of 2 on my quad core > test system. > In file included from include/linux/mman.h:4, from arch/sparc64/kernel/sys_sparc.c:19: include/asm/mman.h:36:1: "MADV_FREE" redefined In file included from include/asm/mman.h:5, from include/linux/mman.h:4, from arch/sparc64/kernel/sys_sparc.c:19: include/asm-generic/mman.h:32:1: this is the location of the previous definition sparc32 and sparc64 already defined MADV_FREE: #define MADV_FREE 0x5 /* (Solaris) contents can be freed */ I'll remove the sparc definitions for now, but we need to work out what we're going to do here. Your patch changes the values of MADV_FREE on sparc. Perhaps this should be renamed to MADV_FREE_LINUX and given a different number. It depends on how close your proposed behaviour is to Solaris's. -- 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