f91bc594ba
The max_scsicmpl_time parameter can be used to perform scsi cmd queue depth mgmt based on io completion time: the queue depth is reduced to make completion time shorter. However, as soon as an io completes and the completion time is within limits, the code immediately bumps the queue depth limit back up to the target queue depth. Thus the procedure restarts, effectively limiting the usefulness of adjusting queue depth to help completion time. This patch makes the following changes: - Removes the code at io completion that resets the queue depth as soon as within limits. - As the code removed was where the target queue depth was first applied, change target queue depth application so that it occurs when the parameter is changed. - Makes target queue depth a standard parameter: both a module parameter and a sysfs parameter. - Optimizes the command pending count by using atomics rather than locks. - Updates the debugfs nodelist stats to allow better debugging of pending command counts. Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com> Signed-off-by: James Smart <james.smart@broadcom.com> Reviewed-by: Hannes Reinecke <hare@suse.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.
See Documentation/00-INDEX for a list of what is contained in each file.
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.