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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 EB002C3F2CD for ; Tue, 3 Mar 2020 01:22:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B5EA624673 for ; Tue, 3 Mar 2020 01:22:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="HJ7XVeuy" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726954AbgCCBWG (ORCPT ); Mon, 2 Mar 2020 20:22:06 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:33510 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726752AbgCCBWG (ORCPT ); Mon, 2 Mar 2020 20:22:06 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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=NojBDjb7TlQCImuRBu0tY2yEVynAhDwavypt4k6px3k=; b=HJ7XVeuy87U2yFbalZXh8bGzml n7bPovrmrBC5k/yQhrSJRZq8DTVrBLSBQs6+tGIBqV8DGk6mQub2r8dnOoFfVOZGMCMEFW6JpaG2z sP8brbDrsxfC7wjYi7cZb94NnyAiA+sYSxqF5tmsQXKtiS0KRf+HkFSPmtOqtok9xzUJQL2ps2V4/ 9YzbumGLYEHF13izP2eZP0RGTDGTfnrZhxwi/BsC48MPhAjAxHOkjissbxfYc3lldz4pZm8mdIJoc gwzLkpULOB3tE8BtICZyosSucGMgTmOZuOV2ZB6HD9D5jgC3dI0v7YBDKG0NDBZn7y2YqNteTP1KG j97AEomg==; Received: from willy by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1j8wG3-0006dp-MG; Tue, 03 Mar 2020 01:22:03 +0000 Date: Mon, 2 Mar 2020 17:22:03 -0800 From: Matthew Wilcox To: Minchan Kim Cc: Andrew Morton , linux-mm , LKML , Jan Kara , Josef Bacik , Johannes Weiner Subject: Re: [PATCH v2] mm: fix long time stall from mm_populate Message-ID: <20200303012203.GR29971@bombadil.infradead.org> References: <20200303002638.206421-1-minchan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200303002638.206421-1-minchan@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Mar 02, 2020 at 04:26:38PM -0800, Minchan Kim wrote: > @@ -1196,6 +1196,7 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors) > struct vm_area_struct *vma = NULL; > int locked = 0; > long ret = 0; > + bool tried = false; How about ... int *lockedp = &locked; > > end = start + len; > > @@ -1226,14 +1227,18 @@ int __mm_populate(unsigned long start, unsigned long len, int ignore_errors) > * double checks the vma flags, so that it won't mlock pages > * if the vma was already munlocked. > */ > - ret = populate_vma_page_range(vma, nstart, nend, &locked); > + ret = populate_vma_page_range(vma, nstart, nend, > + tried ? NULL : &locked); ret = populate_vma_page_range(vma, nstart, nend, lockedp); > if (ret < 0) { > if (ignore_errors) { > ret = 0; > continue; /* continue at next VMA */ > } > break; > - } > + } else if (ret == 0) > + tried = true; > + else > + tried = false; } else if (ret == 0) lockedp = NULL; Maybe there's a better name than lockedp.