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 91F46C433F5 for ; Tue, 21 Dec 2021 09:17:19 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id F33236B0078; Tue, 21 Dec 2021 04:17:18 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id EE1C66B007B; Tue, 21 Dec 2021 04:17:18 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DA9C86B007D; Tue, 21 Dec 2021 04:17:18 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0209.hostedemail.com [216.40.44.209]) by kanga.kvack.org (Postfix) with ESMTP id CAF696B0078 for ; Tue, 21 Dec 2021 04:17:18 -0500 (EST) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id 8B9E68249980 for ; Tue, 21 Dec 2021 09:17:18 +0000 (UTC) X-FDA: 78941247756.17.890D6C5 Received: from mail-qt1-f172.google.com (mail-qt1-f172.google.com [209.85.160.172]) by imf24.hostedemail.com (Postfix) with ESMTP id 3529B18002F for ; Tue, 21 Dec 2021 09:17:14 +0000 (UTC) Received: by mail-qt1-f172.google.com with SMTP id q14so12257000qtx.10 for ; Tue, 21 Dec 2021 01:17:18 -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=GsQvaI7A1wdAxmeueWYfyyxE+cFPs78qCZTLJz4uaZA=; b=Rc/RWdXiq31wiYWyOfSAe3/XzoJsf6eSWj3UqAgso2+3tudJ+pEqajnSp0MX5Ivnfb v7E10N+xuZFfHtjQM2mSDXPtJfFPDEwzTYQ3cAKbGxk7QHB6gC2o3EvLU9VxEEns/tiz X1hl9TOtbzs3rrNAPQfZzn1wMayO+xs4+rDfx89HM8IU5iDPOT9NL2pyYQKO4MieUVPv tZpDXlsBkQYTVoCKgb4E1a6VElwwvxzHfS+8kWzB4UhdcKmmdDvCJNZjZ+cu8BXn1cTz uwuxkPPIh0lj7g3SXk2jTJrWbMZh+Q99aVadlgxINr8y6JYEP+3uBwCpsJdKiymd9vwZ VDSQ== 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=GsQvaI7A1wdAxmeueWYfyyxE+cFPs78qCZTLJz4uaZA=; b=1UvWOMhJy03O8hGUCXQ77lH7p37tEYuL3vpADXuSNmHtGexxHbfNRTAZb6CumSt7Kb Ua+IEwrDcLsCj0j7XcrquVcDsUdfNKb0xk1gpgQuDJ9y1ZCfRyph33xfFxEvdJY+suSk Oh2Oy6qzNjGHSFdh0PpE+1hPPJWalp20tRXa/SJ9X901lPRwddfM7hCYGCXVTlvjHzhw YSBS93xCZd5Pf2V0P3yg8C/zcx2SOTpIXPVOP6disGmLE0+dTIPHTuLTtYU1b5Qqc8GL HkmX/EKMpoWDUul4spwF+0VBvOLbwoXGVrrJMdQCFXGeAJOkrUYF+HH12KIWS+wltbXV NcGw== X-Gm-Message-State: AOAM533QOG/E6ApTnV8qHv4CKH49PspK7eehlV74Zjd5SdWWYgjlLxDM GWVkm2CXyeCR8kdQdadKbmqEeSqdaEBBdaru6+YE0g== X-Google-Smtp-Source: ABdhPJySaSkdGVLLYk9zgNVN+v/hvI55u4ES66+7QrRplSW+Lq21+NQDiGiG71v2c+6hNI+kO5z5N8ahWN2FEGKAbcM= X-Received: by 2002:ac8:5712:: with SMTP id 18mr1304135qtw.72.1640078237345; Tue, 21 Dec 2021 01:17:17 -0800 (PST) MIME-Version: 1.0 References: <92f3029f3647ab355450ed5c8252bad8cfae1e09.1640036051.git.andreyknvl@google.com> In-Reply-To: <92f3029f3647ab355450ed5c8252bad8cfae1e09.1640036051.git.andreyknvl@google.com> From: Alexander Potapenko Date: Tue, 21 Dec 2021 10:16:41 +0100 Message-ID: Subject: Re: [PATCH mm v4 07/39] mm: clarify __GFP_ZEROTAGS comment To: andrey.konovalov@linux.dev Cc: Marco Elver , Andrew Morton , Andrey Konovalov , Dmitry Vyukov , Andrey Ryabinin , kasan-dev , Linux Memory Management List , Vincenzo Frascino , Catalin Marinas , Will Deacon , Mark Rutland , Linux ARM , Peter Collingbourne , Evgenii Stepanov , LKML , Andrey Konovalov Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: 3529B18002F X-Stat-Signature: apda4zjoo5g9rnds51e8et8qpg1edby5 Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b="Rc/RWdXi"; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf24.hostedemail.com: domain of glider@google.com designates 209.85.160.172 as permitted sender) smtp.mailfrom=glider@google.com X-Rspamd-Server: rspam02 X-HE-Tag: 1640078234-474529 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, Dec 20, 2021 at 10:59 PM wrote: > > From: Andrey Konovalov Reviewed-by: Alexander Potapenko > > __GFP_ZEROTAGS is intended as an optimization: if memory is zeroed during > allocation, it's possible to set memory tags at the same time with little > performance impact. Perhaps you could mention this intention explicitly in the comment? Right now it still doesn't reference performance. > > Clarify this intention of __GFP_ZEROTAGS in the comment. > > Signed-off-by: Andrey Konovalov > --- > include/linux/gfp.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/include/linux/gfp.h b/include/linux/gfp.h > index 0b2d2a636164..d6a184523ca2 100644 > --- a/include/linux/gfp.h > +++ b/include/linux/gfp.h > @@ -228,8 +228,8 @@ struct vm_area_struct; > * > * %__GFP_ZERO returns a zeroed page on success. > * > - * %__GFP_ZEROTAGS returns a page with zeroed memory tags on success, if > - * __GFP_ZERO is set. > + * %__GFP_ZEROTAGS zeroes memory tags at allocation time if the memory i= tself > + * is being zeroed (either via __GFP_ZERO or via init_on_alloc). > * > * %__GFP_SKIP_KASAN_POISON returns a page which does not need to be poi= soned > * on deallocation. Typically used for userspace pages. Currently only h= as an > -- > 2.25.1 > > -- > You received this message because you are subscribed to the Google Groups= "kasan-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an= email to kasan-dev+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgi= d/kasan-dev/92f3029f3647ab355450ed5c8252bad8cfae1e09.1640036051.git.andreyk= nvl%40google.com. --=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