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([2601:1c1:8700:f5b:fe34:97ff:fea3:c147]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-38d2fbc64b5sm549778a91.2.2026.07.10.06.23.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Jul 2026 06:23:43 -0700 (PDT) From: Hiroshi Nishida To: Song Liu , Yu Kuai Cc: Li Nan , Xiao Ni , linux-raid@vger.kernel.org, linux-kernel@vger.kernel.org, Hiroshi Nishida Subject: [PATCH 0/2] md/raid5: reduce resync/recovery dispatch overhead Date: Fri, 10 Jul 2026 06:23:37 -0700 Message-ID: <20260710132339.7284-1-nishidafmly@gmail.com> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-raid@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Two changes to how resync/recovery submits work, reducing per-stripe overhead on the rebuild path. Neither adds memory. 1/2 submits a window of stripes per raid5_sync_request() call instead of one at a time. On a rebuild this reduces the number of raid5_sync_request() invocations by ~30x (a call-count measurement, not a throughput figure) and bounds the per-stripe jiffy-sleep that otherwise throttles progress when the stripe cache is under pressure. 2/2 reserves a small amount of stripe cache for user I/O during a rebuild, so foreground I/O is not starved by the resync stream. A pure rebuild with no competing I/O is unchanged. Both touch only the resync/recovery path and are independent of the other md patches I'm sending separately. Hiroshi Nishida (2): md/raid5: submit a window of stripes during resync/recovery md/raid5: reserve stripe cache for user I/O during rebuild drivers/md/raid5.c | 68 +++++++++++++++++++++++++++++++++++++--------- drivers/md/raid5.h | 2 ++ 2 files changed, 57 insertions(+), 13 deletions(-) base-commit: 55b77337bdd088c77461588e5ec094421b89911b -- 2.43.0