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]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id BA234F33A7D for ; Thu, 5 Mar 2026 14:56:01 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 05BA16B0005; Thu, 5 Mar 2026 09:56:01 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 0339A6B0088; Thu, 5 Mar 2026 09:56:00 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id E74B76B0089; Thu, 5 Mar 2026 09:56:00 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id D22866B0005 for ; Thu, 5 Mar 2026 09:56:00 -0500 (EST) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 74038888BE for ; Thu, 5 Mar 2026 14:56:00 +0000 (UTC) X-FDA: 84512309280.07.0E85EA4 Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf05.hostedemail.com (Postfix) with ESMTP id D350E100010 for ; Thu, 5 Mar 2026 14:55:58 +0000 (UTC) Authentication-Results: imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Kn5ytd+7; spf=pass (imf05.hostedemail.com: domain of sj@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1772722558; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=bkPQ3sgkDOoPfp+AeBsnuKOEYfSCX6MisFQPtRAT9xY=; b=Fn1uZMKyQXf5Zs2V3h75MqGUbA6RBdAp5ezpPzFj/Z3Fb4b8rIsKB98qjJNV2OSmfppf5M dkm4zairbtdQIMxWl+miXb+f8yxaop1aTuG6/cmpAO0z2rWEfky0OOKoXhuM1nIdC8e2dp NemwKLhUqFpW7p/4eM580hzQ+vEqLLQ= ARC-Authentication-Results: i=1; imf05.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=Kn5ytd+7; spf=pass (imf05.hostedemail.com: domain of sj@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=sj@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1772722558; a=rsa-sha256; cv=none; b=Yq4JJaRzGMJ2SvXJDUKdkbV1b0s4ME8ZAL92u8CydT1mt1UeVrB0nH67lYO2t0agobi6uv MApbT0rKQJTxOM8rcjKfFeaOIkdC+hL3Gj7hJxxk2/RVXo+AMbWRGH/J+HE9opU/WT5xAK YzTp4GLR19Yz+gQCBslwLcZE0bodXH4= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by tor.source.kernel.org (Postfix) with ESMTP id 3986A61344; Thu, 5 Mar 2026 14:55:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29C8BC116C6; Thu, 5 Mar 2026 14:55:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772722557; bh=amy+SaJwg+WdNFtVzm4GtX3Td8Gs26jX8LxmkTno6mc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Kn5ytd+7nTBuHR5VYD0Y5pcHIekfqTi0HrmCH4uShdxcHMRM7QLt0UwhiTR0IAXYz 8hyJKh3UnfDvpbf53kXXwIhziqGlXZfM6ZO4elMz/qwqRp8PvKa34BhMm3nGfQfsjy 6mJb2bH+1wsynJJnIzCil2M1AxaznsFfQhSK4gzHpjTaB3mlb6qPmBxW/MqVTIvTw8 xZp6Dq7zDPTxggBKUBqxELmoACZFjNpGe8DSbeET7G2D7F02Tvj+o7EWMf6DB8q4yX VIe5zQXI5oniyBBqu7mjnlt+h7uCI2+LLBUN8vpMlXFRZP3RRkekTtfllNd9L3uaBA Xm2NkkFxJkvsA== From: SeongJae Park To: "Vlastimil Babka (SUSE)" Cc: SeongJae Park , Dmitry Ilvokhin , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Axel Rasmussen , Yuanchu Xie , Wei Xu , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , "Rafael J. Wysocki" , Pavel Machek , Len Brown , Brendan Jackman , Johannes Weiner , Zi Yan , Oscar Salvador , Qi Zheng , Shakeel Butt , linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH v4 4/5] mm: rename zone->lock to zone->_lock Date: Thu, 5 Mar 2026 06:55:54 -0800 Message-ID: <20260305145555.86081-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: D350E100010 X-Stat-Signature: fqn5oow7xewezm4irixfhbphhp8rh56n X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1772722558-61539 X-HE-Meta: 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 J9+F4xF6 oXZ53ugGFjLz/J7IhOosC9nzd0X6iwjmWaqKN3SuhxpQgkgNGozPy8o7E16tUigGw9RqvCGQBYs2v1DSKUjCPQn9YJXjyF3miiPfO1nJlEfXOtENvrTNC8x7tpRj4aougfiY8VvHYFJgU9E3BkvFX9pAL7zYjrKWL4a4V0/uimqFLIhoEFdTrgMm7D7eaIS+1LDCqzxdRbBq7pco6QYbogyz67W6oMW3X8EFR1NMWvsYvHHkkpTwCAsugSUAae3LR/d2HreBZzzxDDcgrMc3ULXMKe5XLYS8Xbr1ddUjxgB/paCega/W659qDh8YEaaB6tS/TZTi63NsMpX5ZL8BoZvPRmFwlD/6VH+o15ME1/aKPImtNj8iJghayVZCYfxl2+mdwgzYNkjfu8fA= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, 5 Mar 2026 10:27:07 +0100 "Vlastimil Babka (SUSE)" wrote: > On 3/4/26 16:13, SeongJae Park wrote: > > On Wed, 4 Mar 2026 13:01:45 +0000 Dmitry Ilvokhin wrote: > > > >> On Tue, Mar 03, 2026 at 05:50:34PM -0800, SeongJae Park wrote: > >> > On Tue, 3 Mar 2026 14:25:55 +0000 Dmitry Ilvokhin wrote: > >> > > >> > > On Mon, Mar 02, 2026 at 02:37:43PM -0800, Andrew Morton wrote: > >> > > > On Mon, 2 Mar 2026 15:10:03 +0100 "Vlastimil Babka (SUSE)" wrote: > >> > > > > >> > > > > On 2/27/26 17:00, Dmitry Ilvokhin wrote: > >> > > > > > This intentionally breaks direct users of zone->lock at compile time so > >> > > > > > all call sites are converted to the zone lock wrappers. Without the > >> > > > > > rename, present and future out-of-tree code could continue using > >> > > > > > spin_lock(&zone->lock) and bypass the wrappers and tracing > >> > > > > > infrastructure. > >> > > > > > > >> > > > > > No functional change intended. > >> > > > > > > >> > > > > > Suggested-by: Andrew Morton > >> > > > > > Signed-off-by: Dmitry Ilvokhin > >> > > > > > Acked-by: Shakeel Butt > >> > > > > > Acked-by: SeongJae Park > >> > > > > > >> > > > > I see some more instances of 'zone->lock' in comments in > >> > > > > include/linux/mmzone.h and under Documentation/ but otherwise LGTM. > >> > > > > > >> > > > > >> > > > I fixed (most of) that in the previous version but my fix was lost. > >> > > > >> > > Thanks for the fixups, Andrew. > >> > > > >> > > I still see a few 'zone->lock' references in Documentation remain on > >> > > mm-new. This patch cleans them up, as noted by Vlastimil. > >> > > > >> > > I'm happy to adjust this patch if anything else needs attention. > >> > > > >> > > From 9142d5a8b60038fa424a6033253960682e5a51f4 Mon Sep 17 00:00:00 2001 > >> > > From: Dmitry Ilvokhin > >> > > Date: Tue, 3 Mar 2026 06:13:13 -0800 > >> > > Subject: [PATCH] mm: fix remaining zone->lock references > >> > > > >> > > Signed-off-by: Dmitry Ilvokhin > >> > > --- > >> > > Documentation/mm/physical_memory.rst | 4 ++-- > >> > > Documentation/trace/events-kmem.rst | 8 ++++---- > >> > > 2 files changed, 6 insertions(+), 6 deletions(-) > >> > > > >> > > diff --git a/Documentation/mm/physical_memory.rst b/Documentation/mm/physical_memory.rst > >> > > index b76183545e5b..e344f93515b6 100644 > >> > > --- a/Documentation/mm/physical_memory.rst > >> > > +++ b/Documentation/mm/physical_memory.rst > >> > > @@ -500,11 +500,11 @@ General > >> > > ``nr_isolate_pageblock`` > >> > > Number of isolated pageblocks. It is used to solve incorrect freepage counting > >> > > problem due to racy retrieving migratetype of pageblock. Protected by > >> > > - ``zone->lock``. Defined only when ``CONFIG_MEMORY_ISOLATION`` is enabled. > >> > > + ``zone_lock``. Defined only when ``CONFIG_MEMORY_ISOLATION`` is enabled. > >> > > >> > Dmitry's original patch [1] was doing 's/zone->lock/zone->_lock/', which aligns > >> > to my expectation. But this patch is doing 's/zone->lock/zone_lock/'. Same > >> > for the rest of this patch. > >> > > >> > I was initially thinking this is just a mistake, but I also found Andrew is > >> > doing same change [2], so I'm bit confused. Is this an intentional change? > >> > > >> > [1] https://lore.kernel.org/d61500c5784c64e971f4d328c57639303c475f81.1772206930.git.d@ilvokhin.com > >> > [2] https://lore.kernel.org/20260302143743.220eed4feb36d7572fe726cc@linux-foundation.org > >> > > >> > >> Good catch, thanks for pointing this out, SJ. > >> > >> Originally the mechanical rename was indeed zone->lock -> zone->_lock. > >> However, in Documentation I intentionally switched references to > >> zone_lock instead of zone->_lock. The reasoning is that _lock is now an > >> internal implementation detail, and direct access is discouraged. The > >> intended interface is via the zone_lock_*() / zone_unlock_*() wrappers, > >> so referencing zone_lock in documentation felt more appropriate than > >> mentioning the private struct field (zone->_lock). > > > > Thank you for this nice and kind clarification, Dmitry! I agree mentioning > > zone_[un]lock_*() helpers instead of the hidden member (zone->_lock) can be > > better. > > > > But, I'm concerned if people like me might not aware the intention under > > 'zone_lock'. If there is a well-known convention that allows people to know it > > is for 'zone_[un]lock_*()' helpers, making it more clear would be nice, in my > > humble opinion. If there is such a convention but I'm just missing it, please > > ignore. If I'm not, for eaxmaple, > > > > "protected by ``zone->lock``" could be re-wrote to > > "protected by ``zone_[un]lock_*()`` locking helpers" or, > > "protected by zone lock helper functions (``zone_[un]lock_*()``)" ? > > > >> > >> That said, I agree this creates inconsistency with the mechanical > >> rename, and I'm happy to adjust either way: either consistently refer > >> to the wrapper API, or keep documentation aligned with zone->_lock. > >> > >> I slightly prefer referring to the wrapper API, but don't have a strong > >> preference as long as we're consistent. > > > > I also think both approaches are good. But for the wrapper approach, I think > > giving more contexts rather than just ``zone_lock`` to readers would be nice. > > Grep tells me that we also have comments mentioning simply "zone lock", btw. > And it's also a term used often in informal conversations. Maybe we could > just standardize on that in comments/documentations as it's easier to read. > Discovering that the field is called _lock and that wrappers should be used, > is hopefully not that difficult. Sounds good, that also works for me. Thanks, SJ