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 7AE9AC43458 for ; Tue, 14 Jul 2026 01:20:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 440E46B0005; Mon, 13 Jul 2026 21:20:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3F1536B0088; Mon, 13 Jul 2026 21:20:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 306FA6B008A; Mon, 13 Jul 2026 21:20:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id 0B15E6B0005 for ; Mon, 13 Jul 2026 21:20:17 -0400 (EDT) Received: from smtpin18.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 6050D1401FB for ; Tue, 14 Jul 2026 01:20:16 +0000 (UTC) X-FDA: 84985626432.18.6251227 Received: from out-186.mta1.migadu.com (out-186.mta1.migadu.com [95.215.58.186]) by imf19.hostedemail.com (Postfix) with ESMTP id 8648F1A0002 for ; Tue, 14 Jul 2026 01:20:14 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=aLPVtxei; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf19.hostedemail.com: domain of ridong.chen@linux.dev designates 95.215.58.186 as permitted sender) smtp.mailfrom=ridong.chen@linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1783992014; 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-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ZctEu+mX1koEkj7iSspmtkQvsQ427myBTirKB+Ofv9Q=; b=biiEOoH+ixlAHFOG7rykq5de3hTt8pSAjpTcIduKhlP0oEHH3kWGUHgKI9TzScIkdR3XAU GnkLRvQqxyIvnMx9lMb4NhcgJd6sZ+Xuo0E9nwpjSYbqiDqi/jMGyTEtGs9ieGesjZLuxj mhla3prwgZaFDHHF9MhEV2SGw3h9mKc= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=aLPVtxei; dmarc=pass (policy=none) header.from=linux.dev; spf=pass (imf19.hostedemail.com: domain of ridong.chen@linux.dev designates 95.215.58.186 as permitted sender) smtp.mailfrom=ridong.chen@linux.dev ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1783992014; b=bnaTW/CfiRn3juJeWQp8+0FEIAkC9IM2aDJkQeMnQiFU+Bxj9vbMsEB5m6r+SvtwBqIiyc Kyog6yr5pz2KPJE0WKO3jwE7j1A0JUMyvnkbGLgqqSwSNkeWr2sjbvB+7RcCOvtBSlyqfw nYdeEAGDAO3vWwkUzTaTQTlMcB7Oxv0= Message-ID: <87dc4105-b98b-4541-bafe-c0adfbf58836@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1783992013; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ZctEu+mX1koEkj7iSspmtkQvsQ427myBTirKB+Ofv9Q=; b=aLPVtxeiDDTh4DfW/RDii/1ZK3BCZDRA8W8VefSwdDDRhy2veEza0ita+eFrzjWOY5Bk0U vLbN3hjYA6Wa1jSjTAKTmZn8V8wZFSNkQ3PzQuisAK1lml21UZjnDRdvQqr8v7DUdU0XZf mMwk10gxE/Gqd1uGn2LmMbIK2S+jeTg= Date: Tue, 14 Jul 2026 09:19:53 +0800 MIME-Version: 1.0 Subject: Re: [PATCH 1/2] memcg: move mem_cgroup_swappiness to memcontrol.h To: Barry Song Cc: Andrew Morton , Johannes Weiner , Michal Hocko , Roman Gushchin , Shakeel Butt , Muchun Song , Chris Li , Kairui Song , David Hildenbrand , Yuanchu Xie , linux-mm@kvack.org, cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Ridong Chen References: <20260711091157.306070-1-ridong.chen@linux.dev> <20260711091157.306070-2-ridong.chen@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Ridong Chen In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 8648F1A0002 X-Stat-Signature: 8ptnabhust47ybet65f1h1bfikjzjpwg X-HE-Tag: 1783992014-462876 X-HE-Meta: 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 4XRw6CjV awxBgcUdmzDGdpiDd9yROnDWhAwbxPqFm5Ac63No6PL/z1lKP13iy7aOrFGAkRjsMlejidYvOmVbzichSkJxsmOaLTET5W/AmcEoMjJp+8Iisn7xcqR4BxLW83mCE7ga58PHD1fqCOOeKkFJrPkbXRAOjZ22IKg4vQQ6EVfTngVgR6ChtJ2stW8xGzGc2oX74xXiwyH2C0FqVdonFs7gQ7yIrETakrclu3yEd0UBJFfE6cwQY7Pz8YfuR/ihzPRuYRxFWbLPSlax89JDt5zanfSgkcacwTsklA82bOgEnJ7gaoIxBSyNtETrsNCZ2I3grtQ7Vg93jiJbTyAG42EXtoW5C1XJHwsQBSUR8mQF+Yqpbk6x+JR+ZUdMUZDiZWA5J0NQJ Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 7/13/2026 11:08 PM, Barry Song wrote: > On Sat, Jul 11, 2026 at 5:12 PM Ridong Chen wrote: >> >> From: Ridong Chen >> >> The per-memcg swappiness knob is v1-only; v2 always uses global >> vm_swappiness and ignores the per-cgroup field. >> >> Guard memcg->swappiness with CONFIG_MEMCG_V1, and move the helper >> to memcontrol.h where it belongs. >> >> No functional change for v1; v2-only kernels drop the unused field. >> >> Signed-off-by: Ridong Chen >> Acked-by: Johannes Weiner > > Reviewed-by: Barry Song > > With some nits. > >> --- > [...] >> struct mem_cgroup_per_node *nodeinfo[]; >> @@ -365,6 +366,9 @@ enum objext_flags { >> >> #define OBJEXTS_FLAGS_MASK (__NR_OBJEXTS_FLAGS - 1) >> >> +/* Defined in mm/vmscan.c; used by mem_cgroup_swappiness(). */ >> +extern int vm_swappiness; > > This is a bit unusual. I'm not sure whether mm/swap.h would be > a more appropriate place for this. > Thank you for your reply. The vm_swappiness variable is not utilized within mm/swap.c. Furthermore, since memcontrol.h does not include swap.h, retaining the extern int vm_swappiness declaration in mm/swap.h will result in a compilation failure. -- Best regards Ridong