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Thu, 2 Oct 2025 13:43:00 +0000 (UTC) Received: from localhost (unknown [10.72.112.47]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 7514E19560B1; Thu, 2 Oct 2025 13:42:58 +0000 (UTC) Date: Thu, 2 Oct 2025 21:42:53 +0800 From: Baoquan He To: Chris Li Cc: linux-mm@kvack.org, akpm@linux-foundation.org, kasong@tencent.com, baohua@kernel.org, nphamcs@gmail.com, shikemeng@huaweicloud.com Subject: Re: [PATCH 3/3] mm/swap: remove unneeded swap_active_head Message-ID: References: <20251001043436.41338-1-bhe@redhat.com> <20251001043436.41338-4-bhe@redhat.com> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: nf28VJAp5YUv1w8ipcVs3VaSBPau_YyyEqITHA5E0-U_1759412580 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: DC405140007 X-Rspam-User: X-Rspamd-Server: rspam07 X-Stat-Signature: 4e4ojwyw8nb1bqokhbh4xwazpj5srbf4 X-HE-Tag: 1759412585-486693 X-HE-Meta: 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 NYelhRMF 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 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: List-Subscribe: List-Unsubscribe: On 10/02/25 at 01:33am, Chris Li wrote: > On Tue, Sep 30, 2025 at 9:35 PM Baoquan He wrote: > > > > There's no user of swap_active_head, remove it now. > > Removing swap_active_head for 32 swap devices is less than 1K memory > saving? Only the power off code uses it now so the reduction of > complexity is very limited as well. I consider this series payout is > pretty small but has considerable review overhead. > > Another consideration is that swap.tiers is possible to use the > swap_active_head to find swap devices belonging to a tier, because the > swap tier is a range of priority. We can revisit it after the initial > implementation for swap.tiers. > > Let's hold off the removal of swap_active_head a bit. OK, if it has a potential user, agree we can hold it off for now. Thanks for careful reviewing.