Re: [PATCH 4/6] ublk: initialize io_desc on daemon task
Ming Lei <[email protected]> Thu, 30 Jul 2026 10:10:37 -0500
| Newsgroups | org.kernel.vger.linux-block,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <amtpbb27v0BlRYV5@fedora-laptop> |
On Tue, Jul 28, 2026 at 07:29:49PM -0600, Caleb Sander Mateos wrote: > ublk_setup_iod() is currently called to populate struct ublksrv_io_desc > on the thread submitting I/O to a ublk device. However, only the ublk > server threads read the io_descs. This basically guarantees a cache miss > on both threads for each ublk I/O. There's really no need to initialize > the io_descs on the submitting thread. Move the ublk_setup_iod() call to > ublk_dispatch_req() (for non-UBLK_F_BATCH_IO) and > __ublk_batch_prep_dispatch() (for UBLK_F_BATCH_IO), which runs on the > ublk server daemon thread before dispatching the I/O to userspace. > > Signed-off-by: Caleb Sander Mateos <[email protected]> Reviewed-by: Ming Lei <[email protected]> Thanks, Ming