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 <ushankar@xxxxxxxxxxxxxxx> --- Changes in v4: - Drop "ublk: properly serialize all FETCH_REQs" since Ming is taking it in another set - Prevent data races by marking data structures which should be read-only in the I/O path as const (Ming Lei) - Link to v3: https://lore.kernel.org/r/20250410-ublk_task_per_io-v3-0-b811e8f4554a@xxxxxxxxxxxxxxx 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@xxxxxxxxxxxxxxx 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@xxxxxxxxxxxxxxx --- Uday Shankar (4): ublk: require unique task per io instead of unique task per hctx ublk: mark ublk_queue as const for ublk_commit_and_fetch ublk: mark ublk_queue as const for ublk_register_io_buf ublk: mark ublk_queue as const for ublk_handle_need_get_data drivers/block/ublk_drv.c | 205 +++++++++++++++++++++++------------------------ 1 file changed, 100 insertions(+), 105 deletions(-) --- base-commit: d3b4b25e363e4ce193e6103e64f7de12b96668b9 change-id: 20250408-ublk_task_per_io-c693cf608d7a Best regards, -- Uday Shankar <ushankar@xxxxxxxxxxxxxxx>
