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Tue, 11 Mar 2025 07:05:26 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id zyyYI7bgz2dBRQAAD6G6ig (envelope-from ); Tue, 11 Mar 2025 07:05:26 +0000 Message-ID: Date: Tue, 11 Mar 2025 08:05:26 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm: Decline to manipulate the refcount on a slab page To: Matthew Wilcox Cc: netdev@vger.kernel.org, Vlastimil Babka , linux-mm@kvack.org References: <20250310142750.1209192-1-willy@infradead.org> <77fa8d7e-4752-4979-affe-aa45c8d7795a@suse.de> Content-Language: en-US From: Hannes Reinecke In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam12 X-Rspam-User: X-Rspamd-Queue-Id: E7A3F80009 X-Stat-Signature: 1za4dupstr3qxyzy6ncdp7o7dhwnxa87 X-HE-Tag: 1741676728-6531 X-HE-Meta: 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 NZXzTtBK 5D8jIEwpvfOj/+Ej6ICoLyOhfa/r6E6MnsbKgJNI/64AM4ggQVsxsQItkceODrJzHZKRMgjJaHZcm0ZCINmrMICPe5Ste8dol5PAXHnj5Jmey8mgmKJfAVqQ9dpyxDwkUEuM9ZDZRRgcXHckHym6AbCfZR8LmoP09qBv2/4VTWkx5O8F3l2PSBqea9qBOh2IIth2CXx3fa6c6zCR8wrqfDYaS4gEIHmKwUXxW+qyW52iwLnTcNIOhuSGpGrzdSSaW0/J2a8SmN0M1AU1rQfBGod+PTwhPJrzAfK/3RRoD0tkuqDPjoqVwamXuwvdBwoPG745louBJMPEnoqY= 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 3/10/25 19:28, Matthew Wilcox wrote: > On Mon, Mar 10, 2025 at 05:57:51PM +0100, Hannes Reinecke wrote: >> On 3/10/25 15:27, Matthew Wilcox (Oracle) wrote: >> I assume we will have a discussion at LSF around frozen pages/slab >> behaviour? >> It's not just networking, also every driver using iov_alloc_pages() and >> friends is potentially affected. >> And it would be good to clarify rules how these iterators should be >> used. > > Sure, we can do that. I haven't conducted a deep survey of how many > page users really need a refcount, so I'll have things to learn too. That would be awesome. Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Frankenstr. 146, 90461 Nürnberg HRB 36809 (AG Nürnberg), GF: I. Totev, A. McDonald, W. Knoblich