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Thu, 10 Apr 2025 17:18:08 -0700 (PDT) Received: from c7-smtp-2023.dev.purestorage.com ([208.88.159.129]) by smtp-relay.gmail.com with ESMTPS id d2e1a72fcca58-73bd21e50a8sm17278b3a.13.2025.04.10.17.18.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Apr 2025 17:18:08 -0700 (PDT) X-Relaying-Domain: purestorage.com Received: from dev-ushankar.dev.purestorage.com (dev-ushankar.dev.purestorage.com [IPv6:2620:125:9007:640:7:70:36:0]) by c7-smtp-2023.dev.purestorage.com (Postfix) with ESMTP id CEEF234029E; Thu, 10 Apr 2025 18:18:07 -0600 (MDT) Received: by dev-ushankar.dev.purestorage.com (Postfix, from userid 1557716368) id CE8CAE40E9B; Thu, 10 Apr 2025 18:18:07 -0600 (MDT) From: Uday Shankar Subject: [PATCH v3 0/2] ublk: decouple server threads from hctxs Date: Thu, 10 Apr 2025 18:17:49 -0600 Message-Id: <20250410-ublk_task_per_io-v3-0-b811e8f4554a@purestorage.com> Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-B4-Tracking: v=1; b=H4sIAK5f+GcC/3WOQQqDMBBFr1KybmRMoold9R6lSIyjBluVREOLe PdGoavS5Rt4789KPDqLnlxOK3EYrLfjEIGfT8R0emiR2joyYcAyEKDoUj36cta+Lyd0pR2pyQt umhxULTWJ2uSwsa8jebtH7qyfR/c+FkK6X/eYSAEYY0JwmXBQqlApTeni42av3XVaHO6abjEx4 5PsocC+8p9PAqNAq0IqKTFv6gx+M9u2fQApKRS78wAAAA== X-Change-ID: 20250408-ublk_task_per_io-c693cf608d7a To: Ming Lei , Jens Axboe Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Uday Shankar , Caleb Sander Mateos X-Mailer: b4 0.14.2 This patch set aims to allow ublk server threads to better balance load amongst themselves by decoupling server threads from ublk queues/hctxs, so that multiple threads can service I/Os from a single hctx. Signed-off-by: Uday Shankar --- Changes in v3: - Check for UBLK_IO_FLAG_ACTIVE on I/O again after taking lock to ensure that two concurrent FETCH_REQs on the same I/O can't succeed (Caleb Sander Mateos) - Link to v2: https://lore.kernel.org/r/20250408-ublk_task_per_io-v2-0-b97877e6fd50@purestorage.com Changes in v2: - Remove changes split into other patches - To ease error handling/synchronization, associate each I/O (instead of each queue) to the last task that issues a FETCH_REQ against it. Only that task is allowed to operate on the I/O. - Link to v1: https://lore.kernel.org/r/20241002224437.3088981-1-ushankar@purestorage.com --- Uday Shankar (2): ublk: properly serialize all FETCH_REQs ublk: require unique task per io instead of unique task per hctx drivers/block/ublk_drv.c | 99 +++++++++++++++++++++++++----------------------- 1 file changed, 51 insertions(+), 48 deletions(-) --- base-commit: 88e581728f3f0036110126adbaa0d88d3cd3b48d change-id: 20250408-ublk_task_per_io-c693cf608d7a Best regards,