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 DD1A0C433EF for ; Wed, 2 Mar 2022 18:16:14 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 24E3E8D0002; Wed, 2 Mar 2022 13:16:14 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 1FD388D0001; Wed, 2 Mar 2022 13:16:14 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 0C5AD8D0002; Wed, 2 Mar 2022 13:16:14 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id EF3AD8D0001 for ; Wed, 2 Mar 2022 13:16:13 -0500 (EST) Received: from smtpin15.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id BD63C1D72 for ; Wed, 2 Mar 2022 18:16:13 +0000 (UTC) X-FDA: 79200250626.15.99BC755 Received: from mail-yb1-f180.google.com (mail-yb1-f180.google.com [209.85.219.180]) by imf12.hostedemail.com (Postfix) with ESMTP id 4DC7640022 for ; Wed, 2 Mar 2022 18:16:13 +0000 (UTC) Received: by mail-yb1-f180.google.com with SMTP id f5so5067441ybg.9 for ; Wed, 02 Mar 2022 10:16:13 -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; bh=/VLROJBYuLDdNAp4M2sx7oa2ZYyJWER5sXhuG/3iYEw=; b=VA8P2QicdFFuFTVVowlGiyOo2Qo7vLNdJTy2DraYU4P9l869BIPH5uR348JLzL5olw 3EYlq1i8xbU0evnyZ277YkRf5A9LPXLQx8zpZ0r1HEUu4j+SfnWIbAXKbCd+xmLjmRzE /gNwECIKE4xRjAWzn32m4AnH9AgFxfC+RuVohhLNz3EhPccyGsU/aADkmkTb4F/RkFjf jrxVwkxK6gg/4Jg7PH04AeWJg4IXrmxxEzR7KFWkCV4juEkbd0LDxpzu7u5hBPshJCPe T0gJj8lFrE+t2ZCkmr99EHOEffAdaWtoc3P3BDm8S970FiEv3kw+YSW6gRcydIiBQfx2 1N8g== 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; bh=/VLROJBYuLDdNAp4M2sx7oa2ZYyJWER5sXhuG/3iYEw=; b=o1Sp+OomtjCsEM26fi7frjHn4Ho88GlYUcxMo0T8avBldR16UG35fb8FhWVuoB/Dbw 14BZ75kKm/XS/OElNtbch+k7hlMtpMUk0XLuJ7CB6lUvtEZ2DVr2gzFgdeE3ehnqXjQg LSMv5qR+QHJrMez0LT3AZK64wuhFFS7wBrYLmPUTLkaLRBndfonuamNxDRJYtnQZm8Ek EAoSs4alRtbaltBsoaqldiHOYhM/ns2QPRNtPyd0qUxTdfpFIMkLSTejmH7PDLikGHqH VvzpYphPL9uPbyHuLv/JiXjEyQDTKgjq7qmes+MrFWThBGN34D9LF1fTpPR5eV5Poj+y bVRw== X-Gm-Message-State: AOAM533nrQeRViJ1b7OW3/XIMZj4stOGuRCVjhbxQfTXj3d9cNsEmi2B pCpKkiVw19LlxGYMcwQ3cVQuPykNvv+19FvXULDgcQ== X-Google-Smtp-Source: ABdhPJxfF11g+NiUJhU69r/kUXCaEWmehLJE/e9Ka69kjwLxsa2SFoZq9LkJ5kMyAu58je51UQRqPxMR05DZFQKxCEk= X-Received: by 2002:a05:6902:2:b0:624:4cb5:fd3b with SMTP id l2-20020a056902000200b006244cb5fd3bmr30993410ybh.1.1646244972316; Wed, 02 Mar 2022 10:16:12 -0800 (PST) MIME-Version: 1.0 References: <20220302173122.11939-1-vbabka@suse.cz> <20220302173122.11939-2-vbabka@suse.cz> <4a1c1470-30d0-2a21-0c03-64ffa2fc54c5@suse.cz> In-Reply-To: <4a1c1470-30d0-2a21-0c03-64ffa2fc54c5@suse.cz> From: Marco Elver Date: Wed, 2 Mar 2022 19:15:32 +0100 Message-ID: Subject: Re: [PATCH v2 1/6] lib/stackdepot: allow requesting early initialization dynamically To: Vlastimil Babka Cc: David Rientjes , Christoph Lameter , Joonsoo Kim , Pekka Enberg , Roman Gushchin , Andrew Morton , linux-mm@kvack.org, patches@lists.linux.dev, linux-kernel@vger.kernel.org, Oliver Glitta , Faiyaz Mohammed , Mike Rapoport , Hyeonggon Yoo <42.hyeyoo@gmail.com>, Imran Khan Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 4DC7640022 X-Stat-Signature: 5xhfm5dxkw8ngr91dhoot9oo1qnuff1w X-Rspam-User: Authentication-Results: imf12.hostedemail.com; dkim=pass header.d=google.com header.s=20210112 header.b=VA8P2Qic; dmarc=pass (policy=reject) header.from=google.com; spf=pass (imf12.hostedemail.com: domain of elver@google.com designates 209.85.219.180 as permitted sender) smtp.mailfrom=elver@google.com X-Rspamd-Server: rspam03 X-HE-Tag: 1646244973-484243 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 Wed, 2 Mar 2022 at 19:02, Vlastimil Babka wrote: [...] > > Similarly, for stack_depot_want_early_init, where instead you could > > simply provide stack_depot_want_early_init() as a function, which simply > > sets a boolean __stack_depot_want_early_init. If !STACKDEPOT, it'll also > > just be a no-op function. > > Yeah, makes sense. I guess I have patch 3/6 wrong now anyway as with > !STACKDEPOT it should fail linking due to missing stack_depot_want_early_init... Right. It probably still worked because the compiler likely optimizes out the dead call, but you never know... > >> +bool stack_depot_want_early_init = false; > >> + > > > > This can be __initdata, right? > > I initially thought so too, but in include/linux/init.h found > * Don't forget to initialize data not at file scope, i.e. within a function, > * as gcc otherwise puts the data into the bss section and not into the init > * section. > But maybe that's just outdated as everyone seems to init them at file scope. I think that comment is just about static variables inside functions? Here it's at file scope, so that caveat shouldn't apply. As an aside, you could omit '= false' because it'd zero-init by default. Thanks, -- Marco