Messages in this thread | | | From | Thomas Gleixner <> | Subject | Re: [PATCH 1/2] sched/core: switch struct rq->nr_iowait to a normal int | Date | Thu, 29 Feb 2024 17:53:40 +0100 |
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On Wed, Feb 28 2024 at 12:16, Jens Axboe wrote: > In 3 of the 4 spots where we modify rq->nr_iowait we already hold the
We modify something and hold locks? It's documented that changelogs should not impersonate code. It simply does not make any sense.
> rq lock, and hence don't need atomics to modify the current per-rq > iowait count. In the 4th case, where we are scheduling in on a different > CPU than the task was previously on, we do not hold the previous rq lock, > and hence still need to use an atomic to increment the iowait count. > > Rename the existing nr_iowait to nr_iowait_remote, and use that for the > 4th case. The other three cases can simply inc/dec in a non-atomic > fashion under the held rq lock. > > The per-rq iowait now becomes the difference between the two, the local > count minus the remote count. > > Signed-off-by: Jens Axboe <axboe@kernel.dk>
Other than that:
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
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