Hi All, This patchset supports global tags which was started by Hannes originally: https://marc.info/?l=linux-block&m=149132580511346&w=2 Also inroduce 'force_blk_mq' to 'struct scsi_host_template', so that driver can avoid to support two IO paths(legacy and blk-mq), especially recent discusion mentioned that SCSI_MQ will be enabled at default soon. https://marc.info/?l=linux-scsi&m=151727684915589&w=2 With the above two changes, it should be easier to convert SCSI drivers' reply queue into blk-mq's hctx, then the automatic irq affinity issue can be solved easily, please see detailed descrption in commit log. Also drivers may require to complete request on the submission CPU for avoiding hard/soft deadlock, which can be done easily with blk_mq too. https://marc.info/?t=151601851400001&r=1&w=2 The final patch uses the introduced 'force_blk_mq' to fix virtio_scsi so that IO hang issue can be avoided inside legacy IO path, this issue is a bit generic, at least HPSA/virtio-scsi are found broken with v4.15+. Thanks Ming Ming Lei (5): blk-mq: tags: define several fields of tags as pointer blk-mq: introduce BLK_MQ_F_GLOBAL_TAGS block: null_blk: introduce module parameter of 'g_global_tags' scsi: introduce force_blk_mq scsi: virtio_scsi: fix IO hang by irq vector automatic affinity block/bfq-iosched.c | 4 +-- block/blk-mq-debugfs.c | 11 ++++---- block/blk-mq-sched.c | 2 +- block/blk-mq-tag.c | 67 +++++++++++++++++++++++++++++----------------- block/blk-mq-tag.h | 15 ++++++++--- block/blk-mq.c | 31 ++++++++++++++++----- block/blk-mq.h | 3 ++- block/kyber-iosched.c | 2 +- drivers/block/null_blk.c | 6 +++++ drivers/scsi/hosts.c | 1 + drivers/scsi/virtio_scsi.c | 59 +++------------------------------------- include/linux/blk-mq.h | 2 ++ include/scsi/scsi_host.h | 3 +++ 13 files changed, 105 insertions(+), 101 deletions(-) -- 2.9.5
