On 05/06/2020 12:49, John Garry wrote:
On 05/06/2020 12:44, Ming Lei wrote:
Hi Jens,
The 1st patch avoids to fail driver tag allocation because of inactive
hctx, so hang risk can be killed during cpu hotplug.
The 2nd patch fixes blk_mq_all_tag_iter so that we can drain all
requests before one hctx becomes inactive.
Both fixes bf0beec0607d ("blk-mq: drain I/O when all CPUs in a hctx are
offline").
John has verified that the two can fix his request timeout issue during
cpu hotplug.
But let me test it again my afternoon. My test branch earlier had some
debug stuff.
it looks ok, so the tested-by stands.
BTW, do you agree that the following comment from
__blk_mq_run_hw_queue() is now stale:
"... we depend on blk-mq timeout handler to handle dispatched requests
to this hctx"
Thanks,
John
