From: Ming Lei <ming.lei@redhat.com>
To: Caleb Sander Mateos <csander@purestorage.com>
Cc: Jens Axboe <axboe@kernel.dk>, Shuah Khan <shuah@kernel.org>,
linux-block@vger.kernel.org, linux-kselftest@vger.kernel.org,
linux-kernel@vger.kernel.org,
Stanley Zhang <stazhang@purestorage.com>,
Uday Shankar <ushankar@purestorage.com>
Subject: Re: [PATCH 13/20] ublk: optimize ublk_user_copy() on daemon task
Date: Fri, 26 Dec 2025 10:51:03 +0800 [thread overview]
Message-ID: <aU34F9Y-47IhFWRJ@fedora> (raw)
In-Reply-To: <20251217053455.281509-14-csander@purestorage.com>
On Tue, Dec 16, 2025 at 10:34:47PM -0700, Caleb Sander Mateos wrote:
> ublk user copy syscalls may be issued from any task, so they take a
> reference count on the struct ublk_io to check whether it is owned by
> the ublk server and prevent a concurrent UBLK_IO_COMMIT_AND_FETCH_REQ
> from completing the request. However, if the user copy syscall is issued
> on the io's daemon task, a concurrent UBLK_IO_COMMIT_AND_FETCH_REQ isn't
> possible, so the atomic reference count dance is unnecessary. Check for
> UBLK_IO_FLAG_OWNED_BY_SRV to ensure the request is dispatched to the
> sever and obtain the request from ublk_io's req field instead of looking
> it up on the tagset. Skip the reference count increment and decrement.
> Commit 8a8fe42d765b ("ublk: optimize UBLK_IO_REGISTER_IO_BUF on daemon
> task") made an analogous optimization for ublk zero copy buffer
> registration.
>
> Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Thanks,
Ming
next prev parent reply other threads:[~2025-12-26 2:51 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-12-17 5:34 [PATCH 00/20] ublk: add support for integrity data Caleb Sander Mateos
2025-12-17 5:34 ` [PATCH 01/20] block: validate pi_offset integrity limit Caleb Sander Mateos
2025-12-18 8:53 ` Christoph Hellwig
2025-12-17 5:34 ` [PATCH 02/20] block: validate interval_exp " Caleb Sander Mateos
2025-12-18 8:53 ` Christoph Hellwig
2025-12-17 5:34 ` [PATCH 03/20] blk-integrity: take const pointer in blk_integrity_rq() Caleb Sander Mateos
2025-12-19 14:16 ` Ming Lei
2025-12-17 5:34 ` [PATCH 04/20] ublk: add integrity UAPI Caleb Sander Mateos
2025-12-22 14:26 ` Ming Lei
2025-12-22 15:09 ` Caleb Sander Mateos
2025-12-23 1:51 ` Ming Lei
2025-12-17 5:34 ` [PATCH 05/20] ublk: move ublk flag check functions earlier Caleb Sander Mateos
2025-12-22 14:30 ` Ming Lei
2025-12-17 5:34 ` [PATCH 06/20] ublk: support UBLK_PARAM_TYPE_INTEGRITY in device creation Caleb Sander Mateos
2025-12-22 14:47 ` Ming Lei
2025-12-22 15:35 ` Caleb Sander Mateos
2025-12-23 1:58 ` Ming Lei
2025-12-17 5:34 ` [PATCH 07/20] ublk: set UBLK_IO_F_INTEGRITY in ublksrv_io_desc Caleb Sander Mateos
2025-12-22 14:48 ` Ming Lei
2025-12-17 5:34 ` [PATCH 08/20] ublk: add ublk_copy_user_bvec() helper Caleb Sander Mateos
2025-12-22 14:52 ` Ming Lei
2025-12-22 15:37 ` Caleb Sander Mateos
2025-12-17 5:34 ` [PATCH 09/20] ublk: split out ublk_user_copy() helper Caleb Sander Mateos
2025-12-22 14:58 ` Ming Lei
2025-12-17 5:34 ` [PATCH 10/20] ublk: inline ublk_check_and_get_req() into ublk_user_copy() Caleb Sander Mateos
2025-12-26 2:10 ` Ming Lei
2025-12-17 5:34 ` [PATCH 11/20] ublk: move offset check out of __ublk_check_and_get_req() Caleb Sander Mateos
2025-12-26 2:15 ` Ming Lei
2025-12-17 5:34 ` [PATCH 12/20] ublk: implement integrity user copy Caleb Sander Mateos
2025-12-26 2:38 ` Ming Lei
2025-12-17 5:34 ` [PATCH 13/20] ublk: optimize ublk_user_copy() on daemon task Caleb Sander Mateos
2025-12-26 2:51 ` Ming Lei [this message]
2025-12-17 5:34 ` [PATCH 14/20] selftests: ublk: add utility to get block device metadata size Caleb Sander Mateos
2025-12-17 5:34 ` [PATCH 15/20] selftests: ublk: add kublk support for integrity params Caleb Sander Mateos
2025-12-17 5:34 ` [PATCH 16/20] selftests: ublk: implement integrity user copy in kublk Caleb Sander Mateos
2025-12-17 5:34 ` [PATCH 17/20] selftests: ublk: support non-O_DIRECT backing files Caleb Sander Mateos
2025-12-17 5:34 ` [PATCH 18/20] selftests: ublk: add integrity data support to loop target Caleb Sander Mateos
2025-12-17 5:34 ` [PATCH 19/20] selftests: ublk: add integrity params test Caleb Sander Mateos
2025-12-17 5:34 ` [PATCH 20/20] selftests: ublk: add end-to-end integrity test Caleb Sander Mateos
2025-12-18 16:54 ` (subset) [PATCH 00/20] ublk: add support for integrity data Jens Axboe
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