9e4bec5b2a
Implement mq_poll interface support in megaraid_sas. This feature requires shared host tag support in kernel and driver. The driver can work in non-IRQ mode which means there will not be any MSI-x vector associated for poll_queues. The MegaRAID hardware has a single submission queue and multiple reply queues. However, using the shared host tagset support will enable the driver to simulate multiple hardware queues. Change driver to allocate some extra reply queues which will be marked as poll_queues. These poll_queues will not have associated MSI-x vectors. All I/O completions on these queues will be done through the IOPOLL interface. megaraid_sas with 8 poll_queues and using the io_uring hiprio=1 setting can reach 3.2M IOPS with zero interrupts generated by the hardware. The IOPOLL feature can be enabled using module parameter poll_queues. Link: https://lore.kernel.org/r/20210215074048.19424-3-kashyap.desai@broadcom.com Cc: sumit.saxena@broadcom.com Cc: chandrakanth.patil@broadcom.com Cc: linux-block@vger.kernel.org Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Kashyap Desai <kashyap.desai@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.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.