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Sun, 15 Feb 2026 13:59:25 -0800 (PST) Message-ID: Date: Sun, 15 Feb 2026 14:59:24 -0700 Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/1] io_uring: delay sqarray static branch disablement To: Pavel Begunkov , io-uring@vger.kernel.org References: <8990bf99bc758c6e033e7a75ea5eb1834dd2f920.1771189395.git.asml.silence@gmail.com> <386f4b36-0c53-4ad7-9f71-dff53345ec4f@gmail.com> Content-Language: en-US From: Jens Axboe In-Reply-To: <386f4b36-0c53-4ad7-9f71-dff53345ec4f@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/15/26 2:56 PM, Pavel Begunkov wrote: > On 2/15/26 21:48, Jens Axboe wrote: >> On 2/15/26 2:29 PM, Pavel Begunkov wrote: >>> io_key_has_sqarray static branch can be easily switched >>> on/off by the user. Prevent abuse and defer for a bit when it's >>> disabled. >> >> Can we get something in here for the reason for why the change >> is being made? The commit message really doesn't explain any >> of this. > > It appeared to be pretty self-explanatory, I can expand, but in > short you can spam with It really wasn't! It says "prevent abuse" but is not specific on what kind of abuse this is at all. > while (1) { > create_ring_with_sq_array(); > kill_ring(); > } > > and each iteration it'll be patching kernel code, and that > can be very disruptive for the entire system depending on arch > and how removal is synchronized. OK, so that's the abuse being referred to. I could surely find out by just checking static_branch_slow_dec_deferred() and friends, but a commit message should stand by itself and not need that kind of discovery. Can you just send a v2 with an updated commit message, please? -- Jens Axboe