Quite some drivers are using management commands internally. These commands typically use the same tag pool as regular SCSI commands. Tags for these management commands are set aside before allocating the block-mq tag bitmap for regular SCSI commands. The block layer already supports this via the reserved tag mechanism. Add a new field 'nr_reserved_cmds' to the SCSI host template to instruct the block layer to set aside a tag space for these management commands by using reserved tags. Exclude reserved commands from .can_queue because .can_queue is visible in sysfs. [ bvanassche: modified patch title and patch description. Left out the following statements: "if (sht->nr_reserved_cmds)" and also "if (sdev->host->nr_reserved_cmds) flags |= BLK_MQ_REQ_RESERVED;". Moved nr_reserved_cmds declarations and statements close to the corresponding can_queue declarations and statements. See also https://lore.kernel.org/linux-scsi/20210503150333.130310-11-hare@suse.de/ ] Signed-off-by: Hannes Reinecke <hare@suse.de> Reviewed-by: John Garry <john.g.garry@oracle.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> Link: https://patch.msgid.link/20251031204029.2883185-2-bvanassche@acm.org Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> |
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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 | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .pylintrc | ||
| .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 reStructuredText 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.