| Message ID | 20200605114410.2416726-1-ming.lei@redhat.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | blk-mq: fix handling cpu hotplug | expand |
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. Cheers > > Christoph Hellwig (1): > blk-mq: split out a __blk_mq_get_driver_tag helper > > Ming Lei (1): > blk-mq: fix blk_mq_all_tag_iter > > block/blk-mq-tag.c | 39 ++++++++++++++++++++++++++++++++++++--- > block/blk-mq-tag.h | 8 ++++++++ > block/blk-mq.c | 29 ----------------------------- > block/blk-mq.h | 1 - > 4 files changed, 44 insertions(+), 33 deletions(-) > > Cc: Dongli Zhang <dongli.zhang@oracle.com> > Cc: Hannes Reinecke <hare@suse.de> > Cc: Daniel Wagner <dwagner@suse.de> > Cc: Christoph Hellwig <hch@lst.de> > Cc: John Garry <john.garry@huawei.com> > >
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
On 6/5/20 5:44 AM, 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. Thanks, applied.
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. Christoph Hellwig (1): blk-mq: split out a __blk_mq_get_driver_tag helper Ming Lei (1): blk-mq: fix blk_mq_all_tag_iter block/blk-mq-tag.c | 39 ++++++++++++++++++++++++++++++++++++--- block/blk-mq-tag.h | 8 ++++++++ block/blk-mq.c | 29 ----------------------------- block/blk-mq.h | 1 - 4 files changed, 44 insertions(+), 33 deletions(-) Cc: Dongli Zhang <dongli.zhang@oracle.com> Cc: Hannes Reinecke <hare@suse.de> Cc: Daniel Wagner <dwagner@suse.de> Cc: Christoph Hellwig <hch@lst.de> Cc: John Garry <john.garry@huawei.com>