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Douglas Gilbert
4a0c6f432d
Add a new sdeb_defer_type enumeration: SDEB_DEFER_POLL for requests that have REQ_HIPRI set in cmd_flags field. It is expected that these requests will be polled via the mq_poll entry point which is driven by calls to blk_poll() in the block layer. Therefore timer events are not 'wired up' in the normal fashion. There are still cases with short delays (e.g. < 10 microseconds) where by the time the command response processing occurs, the delay is already exceeded in which case the code calls scsi_done() directly. In such cases there is no window for mq_poll() to be called. Add 'mq_polls' counter that increments on each scsi_done() called via the mq_poll entry point. Can be used to show (with 'cat /proc/scsi/scsi_debug/<host_id>') that blk_poll() is causing completions rather than some other mechanism. Link: https://lore.kernel.org/r/20210215074048.19424-5-kashyap.desai@broadcom.com Tested-by: Kashyap Desai <kashyap.desai@broadcom.com> Signed-off-by: Douglas Gilbert <dgilbert@interlog.com> 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.