mainlining shenanigans
9e3f23f44f
When sending an adminq command, we wait for the command to complete in a loop. This loop waits for an entire millisecond, when in practice the adminq command is processed often much faster. Change the loop to use i40e_usec_delay instead, and wait for 50 usecs each time instead. This appears to be about the minimum time required, based on some manual observation and testing. The primary benefit of this change is reducing latency of various operations in the PF driver, especially when related to having a large number of VFs enabled. For example, on Linux, when instantiating 128 VFs, the time to finish the operation dropped from about 9 seconds down to under 6 seconds. Additionally, the time it takes to finish a PF reset with 128 VFs dropped from 5.1 seconds down to 0.7 seconds. As the examples above show, a significant portion of the delay is wasted waiting for admiqn operations which have already finished. This patch shouldn't cause impact to functionality, as we still check and keep waiting until the command does get processed. The only expected change is an increase in CPU utilization as we now check for completion far more times. However, in practice the commands appear to generally be complete within the first delay window anyways. Change-ID: If8af8388e100da0a14eaf9e1af3afadf73a958cf Signed-off-by: Jacob Keller <jacob.e.keller@intel.com> Tested-by: Andrew Bowers <andrewx.bowers@intel.com> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com> |
||
|---|---|---|
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. 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.