106e4df120
Currently, when the Virtio queue is full, a work item is scheduled to execute in 1ms that retries adding the request to the queue. This is a large amount of time on the scale on which a virtio-fs device can operate. When using a DPU this is around 30-40us baseline without going to a remote server (4k, QD=1). This patch changes the retrying behavior to immediately filling the Virtio queue up again when a completion has been received. This reduces the 99.9th percentile latencies in our tests by 60x and slightly increases the overall throughput, when using a workload IO depth 2x the size of the Virtio queue and a DPU-powered virtio-fs device (NVIDIA BlueField DPU). Signed-off-by: Peter-Jan Gootzen <pgootzen@nvidia.com> Reviewed-by: Max Gurtovoy <mgurtovoy@nvidia.com> Reviewed-by: Yoray Zack <yorayz@nvidia.com> Message-Id: <20240517190435.152096-3-pgootzen@nvidia.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.