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McKenney" Date: Wed, 24 Sep 2025 17:22:09 +0200 In-Reply-To: References: <20250716160603.138385-6-gmonaco@redhat.com> <20250716160603.138385-8-gmonaco@redhat.com> Autocrypt: addr=gmonaco@redhat.com; prefer-encrypt=mutual; keydata=mDMEZuK5YxYJKwYBBAHaRw8BAQdAmJ3dM9Sz6/Hodu33Qrf8QH2bNeNbOikqYtxWFLVm0 1a0JEdhYnJpZWxlIE1vbmFjbyA8Z21vbmFjb0BrZXJuZWwub3JnPoiZBBMWCgBBFiEEysoR+AuB3R Zwp6j270psSVh4TfIFAmjKX2MCGwMFCQWjmoAFCwkIBwICIgIGFQoJCAsCBBYCAwECHgcCF4AACgk Q70psSVh4TfIQuAD+JulczTN6l7oJjyroySU55Fbjdvo52xiYYlMjPG7dCTsBAMFI7dSL5zg98I+8 cXY1J7kyNsY6/dcipqBM4RMaxXsOtCRHYWJyaWVsZSBNb25hY28gPGdtb25hY29AcmVkaGF0LmNvb T6InAQTFgoARAIbAwUJBaOagAULCQgHAgIiAgYVCgkICwIEFgIDAQIeBwIXgBYhBMrKEfgLgd0WcK eo9u9KbElYeE3yBQJoymCyAhkBAAoJEO9KbElYeE3yjX4BAJ/ETNnlHn8OjZPT77xGmal9kbT1bC1 7DfrYVISWV2Y1AP9HdAMhWNAvtCtN2S1beYjNybuK6IzWYcFfeOV+OBWRDQ== User-Agent: Evolution 3.56.2 (3.56.2-2.fc42) MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-MFC-PROC-ID: P_ufZLXXOSXVcOlS2AMFW1H12X7LR4yRU48dS1dmZIE_1758727333 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Stat-Signature: 9zcxoxk3e4tnwhkaryiafwcjubrgxuzk X-Rspam-User: X-Rspamd-Queue-Id: 6D4C818000D X-Rspamd-Server: rspam10 X-HE-Tag: 1758727336-196787 X-HE-Meta: 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 qMa/n/bv 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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 Tue, 2025-08-26 at 14:01 -0400, Mathieu Desnoyers wrote: > Your approach looks good, but please note that this will probably > need to be rebased on top of the rseq rework from Thomas Gleixner. >=20 > Latest version can be found here: >=20 > https://lore.kernel.org/lkml/20250823161326.635281786@linutronix.de/ I rebased and adapted the patches on the V4 of that series. To get close functionality I went back to the task_work and I'm scheduling = it from switches (rseq_sched_switch_event). Quick recap: My series tries to reduce the latency caused by `task_mm_cid_work` on many-= CPU systems. While at it, it improves reliability for bursty tasks that can mis= s the tick. It reduces the latency by splitting the work in batches. This requires more reliability as compaction now needs more runs, which is achieved enqueuing = on switches instead of ticks. While this solution works, my doubt is whether running something there is s= till acceptable, considering Thomas' effort is going in the opposite direction. My tests don't show any significant performance difference, but I'd gladly = try different workloads. Any thoughts on this? If the approach still looks reasonable I can submit a proper series for rev= iew. You can find the series at: git://git.kernel.org/pub/scm/linux/kernel/git/gmonaco/linux.git mm_cid_= batches_rebased Thanks, Gabriele