From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965033AbVHZB0b (ORCPT ); Thu, 25 Aug 2005 21:26:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965034AbVHZB0b (ORCPT ); Thu, 25 Aug 2005 21:26:31 -0400 Received: from smtp206.mail.sc5.yahoo.com ([216.136.129.96]:23409 "HELO smtp206.mail.sc5.yahoo.com") by vger.kernel.org with SMTP id S965033AbVHZB0a (ORCPT ); Thu, 25 Aug 2005 21:26:30 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com.au; h=Received:Message-ID:Date:From:User-Agent:X-Accept-Language:MIME-Version:To:CC:Subject:References:In-Reply-To:Content-Type:Content-Transfer-Encoding; b=pqAVmxGdGbLN88I2k1d+Avs0cWYu+mpAZu9AyZg/0q4yr+GQOfNM7OJnzBDksSDnv25kA92gyj/QbE+RohJfpzHuN+ie1vRHzFPhjdtVJfmM6q0LNi7C4VZUh8s0VHxmw2GvChNorvhQVJkwxB8aiE/wCP6FqojYkuSQqnG4lBI= ; Message-ID: <430E6FD4.9060102@yahoo.com.au> Date: Fri, 26 Aug 2005 11:26:44 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.8) Gecko/20050513 Debian/1.7.8-1 X-Accept-Language: en MIME-Version: 1.0 To: Rik van Riel , Linus Torvalds CC: Ray Fucillo , linux-kernel@vger.kernel.org, Hugh Dickins Subject: Re: process creation time increases linearly with shmem References: <430CBFD1.7020101@intersystems.com> <430D0D6B.100@yahoo.com.au> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Rik van Riel wrote: > On Thu, 25 Aug 2005, Nick Piggin wrote: > > >>fork() can be changed so as not to set up page tables for >>MAP_SHARED mappings. I think that has other tradeoffs like >>initially causing several unavoidable faults reading >>libraries and program text. > > > Actually, libraries and program text are usually mapped > MAP_PRIVATE, so those would still be copied. > Yep, that seems to be the case here. > Skipping MAP_SHARED in fork() sounds like a good idea to me... > Indeed. Linus, can you remember why we haven't done this before? -- SUSE Labs, Novell Inc. Send instant messages to your online friends http://au.messenger.yahoo.com