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Polling drivers in a configuration with 1 Input Queue currently keep their DSCI armed all the way through the poll cycle, until qdio_start_irq() clears it. _Any_ intermittent QDIO interrupt delivered to tiqdio_thinint_handler() will thus cause 1) the 'adapter_int' statistic to be incremented, 2) a call to tiqdio_call_inq_handlers() for this device, and then 3) the 'int_discarded' statistics to be incremented. This causes overhead & complexity in the IRQ path, along with ambiguity in the statistics. On the other hand the device should be in IRQ avoidance mode during a poll cycle, so there won't be a lot of DSCI ping-pong that this micro-optimization could prevent. So align the DSCI handling with what we already do for devices with multiple Input Queues: clear it right away while processing the IRQ. For the non-polling path this means that we no longer need to handle the 1-queue case separately. Signed-off-by: Julian Wiedmann <jwi@linux.ibm.com> Reviewed-by: Benjamin Block <bblock@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.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.