86f767e6fc
Currently, the driver updates doorbell looks like this:
post()
{
wqe.field = 0x111;
wmb();
update_wq_db();
}
update_wq_db()
{
db.field = 0x222;
__raw_writeq(db, db_reg);
}
writeq() is a better choice than __raw_writeq() because it calls dma_wmb()
to barrier in ARM64, and dma_wmb() is better than wmb() for ROCEE device.
This patch removes all wmb() before updating doorbell of SQ/RQ/CQ/SRQ by
replacing __raw_writeq() with writeq() to improve performence. The new
process looks like this:
post()
{
wqe.field = 0x111;
update_wq_db();
}
update_wq_db()
{
db.field = 0x222;
writeq(db, db_reg);
}
Link: https://lore.kernel.org/r/1612517974-31867-8-git-send-email-liweihang@huawei.com
Signed-off-by: Lang Cheng <chenglang@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.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 Restructured Text 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.