baff649144
The nvme driver will freeze the IO queues in response to an admin command with CSE bits set. These bits notify the host that the command that's about to be executed needs to be done exclusively, hence the freeze. The Security Receive command is often reported by multiple vendors with CSE bits set. The reason for this is that the result depends on the previous Security Send. This has nothing to do with IO queues, though, so the driver is taking an overly cautious response to seeing this passthrough command, while unable to fufill the intended admin queue action. Rather than freeze IO during this harmless command, mask off the effects. This freezing is observed to cause IO latency spikes when host software periodically validates the security state of the drives. Signed-off-by: Keith Busch <kbusch@kernel.org> Reviewed-by: Jens Axboe <axboe@kernel.dk> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com> Signed-off-by: Christoph Hellwig <hch@lst.de> |
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|---|---|---|
| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
README
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.