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 B8706C433F5 for ; Thu, 2 Dec 2021 16:14:32 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 25CD46B0072; Thu, 2 Dec 2021 11:14:22 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 20C6D6B0073; Thu, 2 Dec 2021 11:14:22 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0D3BA6B0074; Thu, 2 Dec 2021 11:14:22 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0202.hostedemail.com [216.40.44.202]) by kanga.kvack.org (Postfix) with ESMTP id EEF706B0072 for ; Thu, 2 Dec 2021 11:14:21 -0500 (EST) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id B535C8249980 for ; Thu, 2 Dec 2021 16:14:11 +0000 (UTC) X-FDA: 78873351102.19.63F49E2 Received: from mail-qv1-f47.google.com (mail-qv1-f47.google.com [209.85.219.47]) by imf18.hostedemail.com (Postfix) with ESMTP id C4F554002091 for ; Thu, 2 Dec 2021 16:14:10 +0000 (UTC) Received: by mail-qv1-f47.google.com with SMTP id p3so18166988qvj.9 for ; Thu, 02 Dec 2021 08:14:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=ufkuMHJENZAKBVIrvseO49pb4ZFToj5htqXCloJEnks=; b=Crx2IVA+3FT3DarQIHnHUeky6f0sOi0uyQVyUV5jrn7dSPq4qJ6fXu1TKwVoYru9Mv lXERzjbX5xXWNbnnILttG3dn193EsWXLZU+iwq8aed71iJ4kfDnZAs/kHkymZ/1awlNM fLX7BBPZfZvUg+4KyrempOVuGI3KkIG5e7MJFZBCTU0owbK3Q3G4LQ028mXapsNvnrwW UZnA7ljZEzwMbHaKdFEWf8nFiRXq1SbVyAwDYZSJraplDwo9euYtP0sbGVvq68Gu1BQv hiWyGOYqTb7XSz2rF15AgUM8rQwFWgrv3qwj7y6R9FGxplJsVtxKxzUqkjfCNfAvLd6V KWAA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=ufkuMHJENZAKBVIrvseO49pb4ZFToj5htqXCloJEnks=; b=QPNYvRK7iht11u4EI4jsJZVX83/VFA+hBCUZqNdBB/gJo6Ny2+nXXUBpBPOhpMP5mb pcnnC/fWV7tz0nvmXJIlW8K83OCvBw65PLaHKN81HFzSajxYp18BlYimNv1jaEosWgwS swX7NWFRk0+N2a0N1vwPeQHYag8xWe+5k7asBMQCtlYJ2Eeh5O7ma/y9HQ/g5EoaIERs P0xpg607Z3FWJ+I7Xc7kvA4iIIDSsO7pFUgrANgEUA/5qn7YqnCVE5Xx/kobWbD6aMQ+ O42CrUQeVqTpc7Q/5BtDbM3a111Zv+/S3G/cZ/C/CbrGI4S2wXO1Ech3B4hhvrlzHjJ2 EWfw== X-Gm-Message-State: AOAM532T4jSh146f84RYbVCUV/8T5Ob3ygxOMp+DJ3mjF2dwbcVAUdHV +YIrJ/ZKqxX9Daqs6nomdpg0pjMT/BeZT5vhxZNdQw== X-Google-Smtp-Source: ABdhPJxjUOHGzUULmdGYRPeP5vFSn8K/NzY6SOtvNi1xDsFneFX5rAQN0TOn/uuP8WGVW+Aei30O7ewS4oTjFJjcah0= X-Received: by 2002:a0c:8031:: with SMTP id 46mr14089905qva.126.1638461650530; Thu, 02 Dec 2021 08:14:10 -0800 (PST) MIME-Version: 1.0 References: <984104c118a451fc4afa2eadb7206065f13b7af2.1638308023.git.andreyknvl@google.com> In-Reply-To: <984104c118a451fc4afa2eadb7206065f13b7af2.1638308023.git.andreyknvl@google.com> From: Alexander Potapenko Date: Thu, 2 Dec 2021 17:13:34 +0100 Message-ID: Subject: Re: [PATCH 08/31] kasan, page_alloc: refactor init checks in post_alloc_hook To: andrey.konovalov@linux.dev Cc: Marco Elver , Vincenzo Frascino , Catalin Marinas , Peter Collingbourne , Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev@googlegroups.com, Andrew Morton , linux-mm@kvack.org, Will Deacon , linux-arm-kernel@lists.infradead.org, Evgenii Stepanov , linux-kernel@vger.kernel.org, Andrey Konovalov Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: C4F554002091 X-Stat-Signature: jync34qeofizx7xjzhxbs917fx3ngqq4 Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=Crx2IVA+; spf=pass (imf18.hostedemail.com: domain of glider@google.com designates 209.85.219.47 as permitted sender) smtp.mailfrom=glider@google.com; dmarc=pass (policy=reject) header.from=google.com X-HE-Tag: 1638461650-633231 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000003, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Nov 30, 2021 at 10:41 PM wrote: > > From: Andrey Konovalov > > This patch separates code for zeroing memory from the code clearing tags > in post_alloc_hook(). > > This patch is not useful by itself but makes the simplifications in > the following patches easier to follow. > > This patch does no functional changes. > > Signed-off-by: Andrey Konovalov > --- > mm/page_alloc.c | 18 ++++++++++-------- > 1 file changed, 10 insertions(+), 8 deletions(-) > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index 2ada09a58e4b..0561cdafce36 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -2406,19 +2406,21 @@ inline void post_alloc_hook(struct page *page, un= signed int order, > kasan_alloc_pages(page, order, gfp_flags); > } else { > bool init =3D !want_init_on_free() && want_init_on_alloc(= gfp_flags); > + bool init_tags =3D init && (gfp_flags & __GFP_ZEROTAGS); > > kasan_unpoison_pages(page, order, init); > > - if (init) { > - if (gfp_flags & __GFP_ZEROTAGS) { > - int i; > + if (init_tags) { > + int i; > > - for (i =3D 0; i < 1 << order; i++) > - tag_clear_highpage(page + i); > - } else { > - kernel_init_free_pages(page, 1 << order); > - } > + for (i =3D 0; i < 1 << order; i++) > + tag_clear_highpage(page + i); > + > + init =3D false; I find this a bit twisted and prone to breakages. Maybe just check for (init && !init_tags) below? > } > + > + if (init) > + kernel_init_free_pages(page, 1 << order); > } > > set_page_owner(page, order, gfp_flags); > -- > 2.25.1 > --=20 Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Stra=C3=9Fe, 33 80636 M=C3=BCnchen Gesch=C3=A4ftsf=C3=BChrer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg