From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id CF605C433B4 for ; Wed, 7 Apr 2021 14:51:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9F15461369 for ; Wed, 7 Apr 2021 14:51:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345253AbhDGOwI (ORCPT ); Wed, 7 Apr 2021 10:52:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232041AbhDGOwF (ORCPT ); Wed, 7 Apr 2021 10:52:05 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 34A6EC061756 for ; Wed, 7 Apr 2021 07:51:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=Qrs4g4y7pUiMXOP2oCKKvcPXzqp0XPDWJESZj/qqlBY=; b=GdiW0JU2jUF96T7IuZ6E39ZyzP 364aw6St8b2gy7ozm69nzmi0veJzF7p1mhZ2nNfzvcUMxsmAz3UqMnGJm2GFDKz0MuSysdO4PxN+m YYu1pr/6bHuhNP0UZ8n5vxYwcNULuACliglbM74ZVAshIalk8/uqkmXeFLz3ZPkoeY0A8NIYH2AiD +kVXzpkmpNpI99mivkHuGW8w9O/8KN0I4VJOAffwGkKdpGAHoI9dMB6GulIeo8FsX1LESC0F+kp6e uVInVlFz1G1gyb/rWm4Nhd+Rj2NF1WQb83VIKvleOBA07bDkR66zFbGEZkwVDrstlyD6KuxLddP8i mdoT1I0w==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lU9U4-00EcYB-Ph; Wed, 07 Apr 2021 14:49:06 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 75C66300BD2; Wed, 7 Apr 2021 16:48:44 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 67F822BBEA8E3; Wed, 7 Apr 2021 16:48:44 +0200 (CEST) Date: Wed, 7 Apr 2021 16:48:44 +0200 From: Peter Zijlstra To: Michel Lespinasse Cc: Linux-MM , Laurent Dufour , Michal Hocko , Matthew Wilcox , Rik van Riel , Paul McKenney , Andrew Morton , Suren Baghdasaryan , Joel Fernandes , Rom Lemarchand , Linux-Kernel Subject: Re: [RFC PATCH 11/37] x86/mm: attempt speculative mm faults first Message-ID: References: <20210407014502.24091-1-michel@lespinasse.org> <20210407014502.24091-12-michel@lespinasse.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210407014502.24091-12-michel@lespinasse.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 06, 2021 at 06:44:36PM -0700, Michel Lespinasse wrote: > --- a/arch/x86/mm/fault.c > +++ b/arch/x86/mm/fault.c > @@ -1219,6 +1219,8 @@ void do_user_addr_fault(struct pt_regs *regs, > struct mm_struct *mm; > vm_fault_t fault; > unsigned int flags = FAULT_FLAG_DEFAULT; > + struct vm_area_struct pvma; That's 200 bytes on-stack... I suppose that's just about acceptible, but perhaps we need a comment in struct vm_area_struct to make people aware this things lives on-stack and size really is an issue now.