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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 7EEA8C433E1 for ; Tue, 25 Aug 2020 05:20:00 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 406BA20678 for ; Tue, 25 Aug 2020 05:20:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=popple.id.au header.i=@popple.id.au header.b="vVvt4BaZ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 406BA20678 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=popple.id.au Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BAE5F6B008C; Tue, 25 Aug 2020 01:19:59 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id B60866B0092; Tue, 25 Aug 2020 01:19:59 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A4DA08E000D; Tue, 25 Aug 2020 01:19:59 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0046.hostedemail.com [216.40.44.46]) by kanga.kvack.org (Postfix) with ESMTP id 8F7A26B008C for ; Tue, 25 Aug 2020 01:19:59 -0400 (EDT) Received: from smtpin13.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 4E231362B for ; Tue, 25 Aug 2020 05:19:59 +0000 (UTC) X-FDA: 77187939318.13.trade81_24096db27059 Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin13.hostedemail.com (Postfix) with ESMTP id 0F49F18140B60 for ; Tue, 25 Aug 2020 05:19:59 +0000 (UTC) X-HE-Tag: trade81_24096db27059 X-Filterd-Recvd-Size: 3128 Received: from ozlabs.org (ozlabs.org [203.11.71.1]) by imf18.hostedemail.com (Postfix) with ESMTP for ; Tue, 25 Aug 2020 05:19:57 +0000 (UTC) Received: from authenticated.ozlabs.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by mail.ozlabs.org (Postfix) with ESMTPSA id 4BbHP51BCKz9sR4; Tue, 25 Aug 2020 15:19:53 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=popple.id.au; s=202006; t=1598332793; bh=MTpbfNAqvTkG6db77/xvLASym21B8CMhGSXqP1HtlLQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vVvt4BaZ4udfjy1JvLdr5LEsLneBTrDH7xEb+XK7APb2XjAbB3c/sxw7XDM9pqRCB PKkRSiXGt+ltunZg2XsWCDZsOL0mQ4I10rvltxgYyzVPCrimigfHxhSRbSalPomE57 f4PiBC++1UnPlyf/iyNxfa1+wjQQZENoxbWKsCislDZ287zE01dHlPq95Tmq22c+KR 4D5MH7aMnsbiSC14g0F3rhy/erRARyVv6MVgiezViwp9QBarQ4B8Go/CjI9tAhiUr/ KnvTIt287HS4LMzX/yhsLGwqG35AeBoWdd+xt5eUc2fMm8Z4Yr2ryznl+xUFmQbY0F MHJv+ae/xyu1Q== From: Alistair Popple To: Peter Xu Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Andrew Morton , =?ISO-8859-1?Q?J=E9r=F4me?= Glisse , John Hubbard , Ralph Campbell , stable@vger.kernel.org Subject: Re: [PATCH 2/2] mm/rmap: Fixup copying of soft dirty and uffd ptes Date: Tue, 25 Aug 2020 15:19:50 +1000 Message-ID: <1650521.I2r5EI4MMx@cleo> In-Reply-To: <20200824154359.GA8605@xz-x1> References: <20200824083128.12684-1-alistair@popple.id.au> <20200824083128.12684-2-alistair@popple.id.au> <20200824154359.GA8605@xz-x1> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Rspamd-Queue-Id: 0F49F18140B60 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tuesday, 25 August 2020 1:43:59 AM AEST Peter Xu wrote: > > --- a/mm/migrate.c > > +++ b/mm/migrate.c > > @@ -2427,9 +2427,11 @@ static int migrate_vma_collect_pmd(pmd_t *pmdp, > > > > entry = make_migration_entry(page, mpfn & > > > > MIGRATE_PFN_WRITE); > > > > swp_pte = swp_entry_to_pte(entry); > > > > - if (pte_soft_dirty(pte)) > > + if ((is_swap_pte(pte) && pte_swp_soft_dirty(pte)) > > + || (!is_swap_pte(pte) && pte_soft_dirty(pte))) > > > > swp_pte = pte_swp_mksoft_dirty(swp_pte); > > > > - if (pte_uffd_wp(pte)) > > + if ((is_swap_pte(pte) && pte_swp_uffd_wp(pte)) > > + || (!is_swap_pte(pte) && pte_uffd_wp(pte))) > > > > swp_pte = pte_swp_mkuffd_wp(swp_pte); > > > > set_pte_at(mm, addr, ptep, swp_pte); > > The worst case is we'll call is_swap_pte() four times for each entry. Also > considering we know it's not a pte_none() when reach here, how about: > > if (pte_present(pte)) { > // pte handling of both soft dirty and uffd-wp > } else { > // swap handling of both soft dirty and uffd-wp > } > > ? Works for me, I'd missed we knew it was not a pte_none() so will respin. Thanks! - Alistair > Thanks,