1c970450a7
Inject limit is updated or reset when time_is_before_eq_jiffies( decrease_time_jif + several msecs) or think-time state changes. decrease_time_jif is initialized to 0 and will be set to current jiffies when inject limit is updated or reset. If the jiffies is slightly greater than LONG_MAX, time_is_after_eq_jiffies(0) will keep for a long time, so as time_is_after_eq_jiffies(decrease_time_jif + several msecs). If the think-time state never chages, then the injection will not work as expected for long time. To be more specific: Function bfq_update_inject_limit maybe triggered when jiffies pasts decrease_time_jif + msecs_to_jiffies(10) in bfq_add_request by setting bfqd->wait_dispatch to true. Function bfq_reset_inject_limit are called in two conditions: 1. jiffies pasts bfqq->decrease_time_jif + msecs_to_jiffies(1000) in function bfq_add_request. 2. jiffies pasts bfqq->decrease_time_jif + msecs_to_jiffies(100) or bfq think-time state change from short to long. Fix this by initializing bfqq->decrease_time_jif to current jiffies to trigger service injection soon when service injection conditions are met. Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20230116095153.3810101-4-shikemeng@huaweicloud.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
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.