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Mon, 12 Jan 2026 17:32:13 +0300 Message-ID: Date: Mon, 12 Jan 2026 17:32:10 +0300 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 0/2] mm: improve folio refcount scalability To: Kiryl Shutsemau CC: , , , , , , , , , , , , , , , , , , , , , , , , References: Content-Language: en-US From: Gladyshev Ilya In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.123.123.67] X-ClientProxiedBy: lhrpeml500010.china.huawei.com (7.191.174.240) To mscpeml500003.china.huawei.com (7.188.49.51) X-Stat-Signature: j799f3mb1yf1rfw1kpo17j9owk4bqtcn X-Rspam-User: X-Rspamd-Queue-Id: 5B7674001C X-Rspamd-Server: rspam08 X-HE-Tag: 1768228340-799990 X-HE-Meta: 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 x/oJIyM2 36clWRGAR6vGfTHAn2urSp9JkN/TxyfhRc1TfdKLkgzYmzYu7KxOmv4j5cfAB+t2UQ5hPlh5OTVya8AsChUGeDZjrFkBfFyLR8DHbrms6ldRSosehu2GxMzAlYL268O6PTZ7bq9EhQbURN+BQluvLaO2qTldek13yVrbSOmc5LjVz21ji6vwmuG0awDelm2DG6bQnMHaQ196mR2sJ0pEdDwwPQA== 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 1/12/2026 2:49 PM, Kiryl Shutsemau wrote: > On Mon, Jan 12, 2026 at 11:30:38AM +0300, Gladyshev Ilya wrote: >> Gentle ping on this proposal > > I generally like the idea, but I would like to hear from folks who > actually understand serialization. > > Also, do you have number for "a full CAS loop when the counter is > approaching overflow" thing? > I am not sure that overflow is a real problem because you need a very specific race condition over a long time to achieve it... But as a safeguard, everything lower than 2^31 - #max concurrent accesses (~#num cpu) should work, so let's say 2^30