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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id A9109C4332F for ; Mon, 24 Jan 2022 18:11:05 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 447D86B0093; Mon, 24 Jan 2022 13:11:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3F7426B009C; Mon, 24 Jan 2022 13:11:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2E70E6B00A0; Mon, 24 Jan 2022 13:11:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0237.hostedemail.com [216.40.44.237]) by kanga.kvack.org (Postfix) with ESMTP id 1F0CE6B0093 for ; Mon, 24 Jan 2022 13:11:05 -0500 (EST) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id D550B9366C for ; Mon, 24 Jan 2022 18:11:04 +0000 (UTC) X-FDA: 79065972048.23.BB88D14 Received: from mail-pg1-f176.google.com (mail-pg1-f176.google.com [209.85.215.176]) by imf30.hostedemail.com (Postfix) with ESMTP id 86F4C80002 for ; Mon, 24 Jan 2022 18:11:03 +0000 (UTC) Received: by mail-pg1-f176.google.com with SMTP id t32so16073256pgm.7 for ; Mon, 24 Jan 2022 10:11:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=date:from:to:cc:subject:in-reply-to:message-id:references :mime-version; bh=hplmvL7wDWDjn1QFlc9u8Rz2NqKzd7tI4pOgh4hC0uk=; b=fJF6YWxS67b+WXJ/kZRALafhcc4hw67zf1+uP4o1aZQEKj+2cKcMa6Ka9f/8zrMVxS cqOnxJWlX7WzCZgMu/KyRCJ6ZVTUVUG1uFil+iuinSEImbQqTgnUK1f4MVvWX2WLE3Rb nZ3T5hx0L2rtQwgJOXn/nrNTnmRH7oIMhC9kltY6MuWzhNBkCCjJtdzfRKK+feGgZqk9 un7V0NSk+TjRoF5orh4rlBUZMWeYflBdfi+PmGm15ieTqlRjAapF9/3eatTCSvNwypC/ HlpAKm01mYc9kNVp8gakNZ1DjE1++PM6qzRarq4VXa9/0+qGYwg3aoX9W6CQvuIcSFQh ohxA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:date:from:to:cc:subject:in-reply-to:message-id :references:mime-version; bh=hplmvL7wDWDjn1QFlc9u8Rz2NqKzd7tI4pOgh4hC0uk=; b=w+25BwpgGXESaJX/vXIENl8RZ4zer4wvnfkMYG0inGX6s6ktbN/ic47P0zgHNxaNKg cN7BDUW8FpqcjqS/rs2x1WLLQGpAl1jK2Q4uzXqGYGZX0pdkijMhVVU28zC++dtm/q9k Q429fKMGgmho0J6PRuYLiiCFge6h2nOGQESf5+GjQ3gQwU4kPUE9y2wDMOD2JOrNTwaM GWxB8M1j4S38RUm50mNld8NgIxoxsemgEQPf1KTm2qsX+w30CSe/A4FXG0WdX2mnEtOt u1Z5i2R4ZZPgc0s8XLzNiPBuIHYCq3g7GBal53iu+/gymnYDfm1Lxw+wMZ9Y3k7C7SMb MsMw== X-Gm-Message-State: AOAM533Mla/TqS20M5js4c3tmhdahWwxlXS6at81hTcAubpjS9HiUqBk 5DnRd/yRflLWjPER5CLNhIWZ8g== X-Google-Smtp-Source: ABdhPJzA+Y6+DamPb2TvXy85bCHzGMXiad6+zP/iBggpho3e8gjenXre/Iao0V1J9Sm3JKEKSjW36w== X-Received: by 2002:a63:33cd:: with SMTP id z196mr12457613pgz.78.1643047862575; Mon, 24 Jan 2022 10:11:02 -0800 (PST) Received: from [2620:15c:29:204:1f99:bd65:fcbb:146c] ([2620:15c:29:204:1f99:bd65:fcbb:146c]) by smtp.gmail.com with ESMTPSA id t17sm17288302pfg.207.2022.01.24.10.11.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Jan 2022 10:11:01 -0800 (PST) Date: Mon, 24 Jan 2022 10:11:00 -0800 (PST) From: David Rientjes To: Muchun Song cc: akpm@linux-foundation.org, zi.yan@cs.rutgers.edu, kirill.shutemov@linux.intel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, duanxiongchun@bytedance.com Subject: Re: [PATCH v2 2/2] mm: fix missing cache flush for all tail pages of THP In-Reply-To: <20220124051752.83281-2-songmuchun@bytedance.com> Message-ID: <4d5044e7-cac9-b6e6-1467-59ea6010b0f5@google.com> References: <20220124051752.83281-1-songmuchun@bytedance.com> <20220124051752.83281-2-songmuchun@bytedance.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=fJF6YWxS; spf=pass (imf30.hostedemail.com: domain of rientjes@google.com designates 209.85.215.176 as permitted sender) smtp.mailfrom=rientjes@google.com; dmarc=pass (policy=reject) header.from=google.com X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 86F4C80002 X-Stat-Signature: dun9hr3uffno1cqtp5r1w7e45a96io8m X-HE-Tag: 1643047863-723409 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 Mon, 24 Jan 2022, Muchun Song wrote: > The D-cache maintenance inside move_to_new_page() only consider one page, > there is still D-cache maintenance issue for tail pages of THP. Fix this > by not using flush_dcache_folio() since it is not backportable. > The mention of being backportable suggests that we should backport this, likely to 4.14+. So should it be marked as stable? That aside, should there be a follow-up patch that converts to using flush_dcache_folio()? > Fixes: 616b8371539a ("mm: thp: enable thp migration in generic path") > Signed-off-by: Muchun Song > --- > Changes in v2: > - Using a for loop instead of the folio variant for backportable. > > mm/migrate.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/mm/migrate.c b/mm/migrate.c > index c9296d63878d..c418e8d92b9c 100644 > --- a/mm/migrate.c > +++ b/mm/migrate.c > @@ -933,9 +933,12 @@ static int move_to_new_page(struct page *newpage, struct page *page, > if (!PageMappingFlags(page)) > page->mapping = NULL; > > - if (likely(!is_zone_device_page(newpage))) > - flush_dcache_page(newpage); > + if (likely(!is_zone_device_page(newpage))) { > + int i, nr = compound_nr(newpage); > > + for (i = 0; i < nr; i++) > + flush_dcache_page(newpage + i); > + } > } > out: > return rc; > -- > 2.11.0 > > >