* [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully @ 2021-08-02 9:14 Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 1/8] nvme-fc: Update hardware queues before using them Daniel Wagner ` (7 more replies) 0 siblings, 8 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-02 9:14 UTC (permalink / raw) To: linux-kernel Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg, Hannes Reinecke, Wen Xiong, Daniel Wagner Hi, This update version makes sure the unfreeze call is done when recreating the queues. I was able to reproduce hanging I/Os when we go into error recovery mode for FC and TCP [1]. Unfortunatly, I don't have access to a RDMA setup to verify but as the code is identically to the TCP, RDMA looks to like to suffer from the same problem. Thanks, Daniel [1] https://lore.kernel.org/linux-nvme/20210730094907.5vg7qebggttibogz@beryllium.lan/ https://lore.kernel.org/linux-nvme/20210730113415.wezsrvxv5cu4yz4x@beryllium.lan/ v1: - https://lore.kernel.org/linux-nvme/20210625101649.49296-1-dwagner@suse.de/ v2: - https://lore.kernel.org/linux-nvme/20210708092755.15660-1-dwagner@suse.de/ - reviewed tags collected - added 'update hardware queues' for all transport - added fix for fc hanger in nvme_wait_freeze_timeout v3: - https://lore.kernel.org/linux-nvme/20210720124353.127959-1-dwagner@suse.de/ - dropped 'nvme-fc: Freeze queues before destroying them' - added James' two patches v4: - added 'nvme-*: Unfreeze queues on reconnect' - added Hannes' reviewed tags Daniel Wagner (5): nvme-fc: Update hardware queues before using them nvme-rdma: Update number of hardware queues before using them nvme-fc: Wait with a timeout for queue to freeze nvme-tcp: Unfreeze queues on reconnect nvme-rdma: Unfreeze queues on reconnect Hannes Reinecke (1): nvme-tcp: Update number of hardware queues before using them James Smart (2): nvme-fc: avoid race between time out and tear down nvme-fc: fix controller reset hang during traffic drivers/nvme/host/fc.c | 28 +++++++++++++++++++--------- drivers/nvme/host/rdma.c | 15 ++++++++------- drivers/nvme/host/tcp.c | 18 +++++++++--------- 3 files changed, 36 insertions(+), 25 deletions(-) -- 2.29.2 ^ permalink raw reply [flat|nested] 23+ messages in thread
* [PATCH v4 1/8] nvme-fc: Update hardware queues before using them 2021-08-02 9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner @ 2021-08-02 9:14 ` Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 2/8] nvme-tcp: Update number of " Daniel Wagner ` (6 subsequent siblings) 7 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-02 9:14 UTC (permalink / raw) To: linux-kernel Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg, Hannes Reinecke, Wen Xiong, Daniel Wagner, James Smart In case the number of hardware queues changes, do the update the tagset and ctx to hctx first before using the mapping to recreate and connnect the IO queues. Reviewed-by: James Smart <jsmart2021@gmail.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Daniel Wagner <dwagner@suse.de> --- drivers/nvme/host/fc.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c index 7f462af1b02a..8a903769364f 100644 --- a/drivers/nvme/host/fc.c +++ b/drivers/nvme/host/fc.c @@ -2951,14 +2951,6 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl) if (ctrl->ctrl.queue_count == 1) return 0; - ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.sqsize + 1); - if (ret) - goto out_free_io_queues; - - ret = nvme_fc_connect_io_queues(ctrl, ctrl->ctrl.sqsize + 1); - if (ret) - goto out_delete_hw_queues; - if (prior_ioq_cnt != nr_io_queues) { dev_info(ctrl->ctrl.device, "reconnect: revising io queue count from %d to %d\n", @@ -2968,6 +2960,14 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl) nvme_unfreeze(&ctrl->ctrl); } + ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.sqsize + 1); + if (ret) + goto out_free_io_queues; + + ret = nvme_fc_connect_io_queues(ctrl, ctrl->ctrl.sqsize + 1); + if (ret) + goto out_delete_hw_queues; + return 0; out_delete_hw_queues: -- 2.29.2 ^ permalink raw reply related [flat|nested] 23+ messages in thread
* [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them 2021-08-02 9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 1/8] nvme-fc: Update hardware queues before using them Daniel Wagner @ 2021-08-02 9:14 ` Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 3/8] nvme-rdma: " Daniel Wagner ` (5 subsequent siblings) 7 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-02 9:14 UTC (permalink / raw) To: linux-kernel Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg, Hannes Reinecke, Wen Xiong, Daniel Wagner From: Hannes Reinecke <hare@suse.de> When the number of hardware queues changes during resetting we should update the tagset first before using it. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Daniel Wagner <dwagner@suse.de> --- drivers/nvme/host/tcp.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 0a97ba02f61e..32268f24f62a 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -1789,6 +1789,7 @@ static void nvme_tcp_destroy_io_queues(struct nvme_ctrl *ctrl, bool remove) static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) { int ret; + u32 prior_q_cnt = ctrl->queue_count; ret = nvme_tcp_alloc_io_queues(ctrl); if (ret) @@ -1806,14 +1807,7 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) ret = PTR_ERR(ctrl->connect_q); goto out_free_tag_set; } - } - - ret = nvme_tcp_start_io_queues(ctrl); - if (ret) - goto out_cleanup_connect_q; - - if (!new) { - nvme_start_queues(ctrl); + } else if (prior_q_cnt != ctrl->queue_count) { if (!nvme_wait_freeze_timeout(ctrl, NVME_IO_TIMEOUT)) { /* * If we timed out waiting for freeze we are likely to @@ -1828,6 +1822,10 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) nvme_unfreeze(ctrl); } + ret = nvme_tcp_start_io_queues(ctrl); + if (ret) + goto out_cleanup_connect_q; + return 0; out_wait_freeze_timed_out: -- 2.29.2 ^ permalink raw reply related [flat|nested] 23+ messages in thread
* [PATCH v4 3/8] nvme-rdma: Update number of hardware queues before using them 2021-08-02 9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 1/8] nvme-fc: Update hardware queues before using them Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 2/8] nvme-tcp: Update number of " Daniel Wagner @ 2021-08-02 9:14 ` Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 4/8] nvme-fc: Wait with a timeout for queue to freeze Daniel Wagner ` (4 subsequent siblings) 7 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-02 9:14 UTC (permalink / raw) To: linux-kernel Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg, Hannes Reinecke, Wen Xiong, Daniel Wagner When the number of hardware queues changes during resetting we should update the tagset first before using it. Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Daniel Wagner <dwagner@suse.de> --- drivers/nvme/host/rdma.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c index 69ae67652f38..de2a8950d282 100644 --- a/drivers/nvme/host/rdma.c +++ b/drivers/nvme/host/rdma.c @@ -965,6 +965,7 @@ static void nvme_rdma_destroy_io_queues(struct nvme_rdma_ctrl *ctrl, static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new) { int ret; + u32 prior_q_cnt = ctrl->ctrl.queue_count; ret = nvme_rdma_alloc_io_queues(ctrl); if (ret) @@ -982,13 +983,7 @@ static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new) ret = PTR_ERR(ctrl->ctrl.connect_q); goto out_free_tag_set; } - } - - ret = nvme_rdma_start_io_queues(ctrl); - if (ret) - goto out_cleanup_connect_q; - - if (!new) { + } else if (prior_q_cnt != ctrl->ctrl.queue_count) { nvme_start_queues(&ctrl->ctrl); if (!nvme_wait_freeze_timeout(&ctrl->ctrl, NVME_IO_TIMEOUT)) { /* @@ -1004,6 +999,10 @@ static int nvme_rdma_configure_io_queues(struct nvme_rdma_ctrl *ctrl, bool new) nvme_unfreeze(&ctrl->ctrl); } + ret = nvme_rdma_start_io_queues(ctrl); + if (ret) + goto out_cleanup_connect_q; + return 0; out_wait_freeze_timed_out: -- 2.29.2 ^ permalink raw reply related [flat|nested] 23+ messages in thread
* [PATCH v4 4/8] nvme-fc: Wait with a timeout for queue to freeze 2021-08-02 9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner ` (2 preceding siblings ...) 2021-08-02 9:14 ` [PATCH v4 3/8] nvme-rdma: " Daniel Wagner @ 2021-08-02 9:14 ` Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 5/8] nvme-fc: avoid race between time out and tear down Daniel Wagner ` (3 subsequent siblings) 7 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-02 9:14 UTC (permalink / raw) To: linux-kernel Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg, Hannes Reinecke, Wen Xiong, Daniel Wagner, James Smart Do not wait indifinitly for all queues to freeze. Instead use a timeout and abort the operation if we get stuck. Reviewed-by: James Smart <jsmart2021@gmail.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Daniel Wagner <dwagner@suse.de> --- drivers/nvme/host/fc.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c index 8a903769364f..dbb8ad816df8 100644 --- a/drivers/nvme/host/fc.c +++ b/drivers/nvme/host/fc.c @@ -2955,7 +2955,14 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl) dev_info(ctrl->ctrl.device, "reconnect: revising io queue count from %d to %d\n", prior_ioq_cnt, nr_io_queues); - nvme_wait_freeze(&ctrl->ctrl); + if (!nvme_wait_freeze_timeout(&ctrl->ctrl, NVME_IO_TIMEOUT)) { + /* + * If we timed out waiting for freeze we are likely to + * be stuck. Fail the controller initialization just + * to be safe. + */ + return -ENODEV; + } blk_mq_update_nr_hw_queues(&ctrl->tag_set, nr_io_queues); nvme_unfreeze(&ctrl->ctrl); } -- 2.29.2 ^ permalink raw reply related [flat|nested] 23+ messages in thread
* [PATCH v4 5/8] nvme-fc: avoid race between time out and tear down 2021-08-02 9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner ` (3 preceding siblings ...) 2021-08-02 9:14 ` [PATCH v4 4/8] nvme-fc: Wait with a timeout for queue to freeze Daniel Wagner @ 2021-08-02 9:14 ` Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic Daniel Wagner ` (2 subsequent siblings) 7 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-02 9:14 UTC (permalink / raw) To: linux-kernel Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg, Hannes Reinecke, Wen Xiong, James Smart, Chao Leng, Daniel Wagner From: James Smart <jsmart2021@gmail.com> To avoid race between time out and tear down, in tear down process, first we quiesce the queue, and then delete the timer and cancel the time out work for the queue. This patch merges the admin and io sync ops into the queue teardown logic as shown in the RDMA patch 3017013dcc "nvme-rdma: avoid race between time out and tear down". There is no teardown_lock in nvme-fc. Signed-off-by: James Smart <jsmart2021@gmail.com> CC: Chao Leng <lengchao@huawei.com> Tested-by: Daniel Wagner <dwagner@suse.de> [dwagner: updated commit id referenced in commit message] Reviewed-by: Daniel Wagner <dwagner@suse.de> Reviewed-by: Hannes Reinecke <hare@suse.de> --- drivers/nvme/host/fc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c index dbb8ad816df8..133b87db4f1d 100644 --- a/drivers/nvme/host/fc.c +++ b/drivers/nvme/host/fc.c @@ -2487,6 +2487,7 @@ __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues) */ if (ctrl->ctrl.queue_count > 1) { nvme_stop_queues(&ctrl->ctrl); + nvme_sync_io_queues(&ctrl->ctrl); blk_mq_tagset_busy_iter(&ctrl->tag_set, nvme_fc_terminate_exchange, &ctrl->ctrl); blk_mq_tagset_wait_completed_request(&ctrl->tag_set); @@ -2510,6 +2511,7 @@ __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues) * clean up the admin queue. Same thing as above. */ blk_mq_quiesce_queue(ctrl->ctrl.admin_q); + blk_sync_queue(ctrl->ctrl.admin_q); blk_mq_tagset_busy_iter(&ctrl->admin_tag_set, nvme_fc_terminate_exchange, &ctrl->ctrl); blk_mq_tagset_wait_completed_request(&ctrl->admin_tag_set); -- 2.29.2 ^ permalink raw reply related [flat|nested] 23+ messages in thread
* [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic 2021-08-02 9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner ` (4 preceding siblings ...) 2021-08-02 9:14 ` [PATCH v4 5/8] nvme-fc: avoid race between time out and tear down Daniel Wagner @ 2021-08-02 9:14 ` Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 7/8] nvme-tcp: Unfreeze queues on reconnect Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 8/8] nvme-rdma: " Daniel Wagner 7 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-02 9:14 UTC (permalink / raw) To: linux-kernel Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg, Hannes Reinecke, Wen Xiong, James Smart, Daniel Wagner From: James Smart <jsmart2021@gmail.com> commit fe35ec58f0d3 ("block: update hctx map when use multiple maps") exposed an issue where we may hang trying to wait for queue freeze during I/O. We call blk_mq_update_nr_hw_queues which may attempt to freeze the queue. However we never started queue freeze when starting the reset, which means that we have inflight pending requests that entered the queue that we will not complete once the queue is quiesced. So start a freeze before we quiesce the queue, and unfreeze the queue after we successfully connected the I/O queues (the unfreeze is already present in the code). blk_mq_update_nr_hw_queues will be called only after we are sure that the queue was already frozen. This follows to how the pci driver handles resets. This patch added logic introduced in commit 9f98772ba307 "nvme-rdma: fix controller reset hang during traffic". Signed-off-by: James Smart <jsmart2021@gmail.com> CC: Sagi Grimberg <sagi@grimberg.me> [dwagner: call nvme_unfreeze() unconditionally in nvme_fc_recreate_io_queues() to match the nvme_start_freeze()] Tested-by: Daniel Wagner <dwagner@suse.de> Reviewed-by: Daniel Wagner <dwagner@suse.de> --- drivers/nvme/host/fc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c index 133b87db4f1d..b292af0fd655 100644 --- a/drivers/nvme/host/fc.c +++ b/drivers/nvme/host/fc.c @@ -2486,6 +2486,7 @@ __nvme_fc_abort_outstanding_ios(struct nvme_fc_ctrl *ctrl, bool start_queues) * (but with error status). */ if (ctrl->ctrl.queue_count > 1) { + nvme_start_freeze(&ctrl->ctrl); nvme_stop_queues(&ctrl->ctrl); nvme_sync_io_queues(&ctrl->ctrl); blk_mq_tagset_busy_iter(&ctrl->tag_set, @@ -2966,8 +2967,8 @@ nvme_fc_recreate_io_queues(struct nvme_fc_ctrl *ctrl) return -ENODEV; } blk_mq_update_nr_hw_queues(&ctrl->tag_set, nr_io_queues); - nvme_unfreeze(&ctrl->ctrl); } + nvme_unfreeze(&ctrl->ctrl); ret = nvme_fc_create_hw_io_queues(ctrl, ctrl->ctrl.sqsize + 1); if (ret) -- 2.29.2 ^ permalink raw reply related [flat|nested] 23+ messages in thread
* [PATCH v4 7/8] nvme-tcp: Unfreeze queues on reconnect 2021-08-02 9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner ` (5 preceding siblings ...) 2021-08-02 9:14 ` [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic Daniel Wagner @ 2021-08-02 9:14 ` Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 8/8] nvme-rdma: " Daniel Wagner 7 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-02 9:14 UTC (permalink / raw) To: linux-kernel Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg, Hannes Reinecke, Wen Xiong, Daniel Wagner During the queue teardown in nvme_tcp_teardown_io_queues() freeze is called unconditionally. When we reconnect we need to pair the freeze with an unfreeze to avoid hanging I/Os. For newly created connection this is not needed. Fixes: 2875b0aecabe ("nvme-tcp: fix controller reset hang during traffic") Signed-off-by: Daniel Wagner <dwagner@suse.de> --- drivers/nvme/host/tcp.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 32268f24f62a..097f7dd10ed3 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -1819,9 +1819,11 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) } blk_mq_update_nr_hw_queues(ctrl->tagset, ctrl->queue_count - 1); - nvme_unfreeze(ctrl); } + if (!new) + nvme_unfreeze(ctrl); + ret = nvme_tcp_start_io_queues(ctrl); if (ret) goto out_cleanup_connect_q; -- 2.29.2 ^ permalink raw reply related [flat|nested] 23+ messages in thread
* [PATCH v4 8/8] nvme-rdma: Unfreeze queues on reconnect 2021-08-02 9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner ` (6 preceding siblings ...) 2021-08-02 9:14 ` [PATCH v4 7/8] nvme-tcp: Unfreeze queues on reconnect Daniel Wagner @ 2021-08-02 9:14 ` Daniel Wagner 7 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-02 9:14 UTC (permalink / raw) To: linux-kernel Cc: James Smart, Keith Busch, Ming Lei, Sagi Grimberg, Hannes Reinecke, Wen Xiong, Daniel Wagner During the queue teardown in nvme_rdma_teardown_io_queues() freeze is called unconditionally. When we reconnect we need to pair the freeze with an unfreeze to avoid hanging I/Os. For newly created connection this is not needed. Fixes: 9f98772ba307 ("nvme-rdma: fix controller reset hang during traffic") Signed-off-by: Daniel Wagner <dwagner@suse.de> --- drivers/nvme/host/rdma.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c index de2a8950d282..21a8a5353af0 100644 --- a/drivers/nvme/host/rdma.c +++ b/drivers/nvme/host/rdma.c @@ -901,6 +901,8 @@ static int nvme_rdma_configure_admin_queue(struct nvme_rdma_ctrl *ctrl, error = PTR_ERR(ctrl->ctrl.admin_q); goto out_cleanup_fabrics_q; } + } else { + nvme_unfreeze(&ctrl->ctrl); } error = nvme_rdma_start_queue(ctrl, 0); -- 2.29.2 ^ permalink raw reply related [flat|nested] 23+ messages in thread
* [PATCH RESEND v4 0/8] Handle update hardware queues and queue freeze more carefully @ 2021-08-02 11:26 Daniel Wagner 2021-08-02 11:26 ` Daniel Wagner 0 siblings, 1 reply; 23+ messages in thread From: Daniel Wagner @ 2021-08-02 11:26 UTC (permalink / raw) To: linux-nvme Cc: linux-kernel, James Smart, Keith Busch, Ming Lei, Sagi Grimberg, Hannes Reinecke, Wen Xiong, Daniel Wagner [forgot to add the linux-nvme mailing list] Hi, This update version makes sure the unfreeze call is done when recreating the queues. I was able to reproduce hanging I/Os when we go into error recovery mode for FC and TCP [1]. Unfortunatly, I don't have access to a RDMA setup to verify but as the code is identically to the TCP, RDMA looks to like to suffer from the same problem. Thanks, Daniel [1] https://lore.kernel.org/linux-nvme/20210730094907.5vg7qebggttibogz@beryllium.lan/ https://lore.kernel.org/linux-nvme/20210730113415.wezsrvxv5cu4yz4x@beryllium.lan/ v1: - https://lore.kernel.org/linux-nvme/20210625101649.49296-1-dwagner@suse.de/ v2: - https://lore.kernel.org/linux-nvme/20210708092755.15660-1-dwagner@suse.de/ - reviewed tags collected - added 'update hardware queues' for all transport - added fix for fc hanger in nvme_wait_freeze_timeout v3: - https://lore.kernel.org/linux-nvme/20210720124353.127959-1-dwagner@suse.de/ - dropped 'nvme-fc: Freeze queues before destroying them' - added James' two patches v4: - added 'nvme-*: Unfreeze queues on reconnect' - added Hannes' reviewed tags Daniel Wagner (5): nvme-fc: Update hardware queues before using them nvme-rdma: Update number of hardware queues before using them nvme-fc: Wait with a timeout for queue to freeze nvme-tcp: Unfreeze queues on reconnect nvme-rdma: Unfreeze queues on reconnect Hannes Reinecke (1): nvme-tcp: Update number of hardware queues before using them James Smart (2): nvme-fc: avoid race between time out and tear down nvme-fc: fix controller reset hang during traffic drivers/nvme/host/fc.c | 28 +++++++++++++++++++--------- drivers/nvme/host/rdma.c | 15 ++++++++------- drivers/nvme/host/tcp.c | 18 +++++++++--------- 3 files changed, 36 insertions(+), 25 deletions(-) -- 2.29.2 ^ permalink raw reply [flat|nested] 23+ messages in thread
* [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them 2021-08-02 11:26 [PATCH RESEND v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner @ 2021-08-02 11:26 ` Daniel Wagner 0 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-02 11:26 UTC (permalink / raw) To: linux-nvme Cc: linux-kernel, James Smart, Keith Busch, Ming Lei, Sagi Grimberg, Hannes Reinecke, Wen Xiong, Daniel Wagner From: Hannes Reinecke <hare@suse.de> When the number of hardware queues changes during resetting we should update the tagset first before using it. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Daniel Wagner <dwagner@suse.de> --- drivers/nvme/host/tcp.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 0a97ba02f61e..32268f24f62a 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -1789,6 +1789,7 @@ static void nvme_tcp_destroy_io_queues(struct nvme_ctrl *ctrl, bool remove) static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) { int ret; + u32 prior_q_cnt = ctrl->queue_count; ret = nvme_tcp_alloc_io_queues(ctrl); if (ret) @@ -1806,14 +1807,7 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) ret = PTR_ERR(ctrl->connect_q); goto out_free_tag_set; } - } - - ret = nvme_tcp_start_io_queues(ctrl); - if (ret) - goto out_cleanup_connect_q; - - if (!new) { - nvme_start_queues(ctrl); + } else if (prior_q_cnt != ctrl->queue_count) { if (!nvme_wait_freeze_timeout(ctrl, NVME_IO_TIMEOUT)) { /* * If we timed out waiting for freeze we are likely to @@ -1828,6 +1822,10 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) nvme_unfreeze(ctrl); } + ret = nvme_tcp_start_io_queues(ctrl); + if (ret) + goto out_cleanup_connect_q; + return 0; out_wait_freeze_timed_out: -- 2.29.2 ^ permalink raw reply related [flat|nested] 23+ messages in thread
* [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them @ 2021-08-02 11:26 ` Daniel Wagner 0 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-02 11:26 UTC (permalink / raw) To: linux-nvme Cc: linux-kernel, James Smart, Keith Busch, Ming Lei, Sagi Grimberg, Hannes Reinecke, Wen Xiong, Daniel Wagner From: Hannes Reinecke <hare@suse.de> When the number of hardware queues changes during resetting we should update the tagset first before using it. Signed-off-by: Hannes Reinecke <hare@suse.de> Signed-off-by: Daniel Wagner <dwagner@suse.de> --- drivers/nvme/host/tcp.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c index 0a97ba02f61e..32268f24f62a 100644 --- a/drivers/nvme/host/tcp.c +++ b/drivers/nvme/host/tcp.c @@ -1789,6 +1789,7 @@ static void nvme_tcp_destroy_io_queues(struct nvme_ctrl *ctrl, bool remove) static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) { int ret; + u32 prior_q_cnt = ctrl->queue_count; ret = nvme_tcp_alloc_io_queues(ctrl); if (ret) @@ -1806,14 +1807,7 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) ret = PTR_ERR(ctrl->connect_q); goto out_free_tag_set; } - } - - ret = nvme_tcp_start_io_queues(ctrl); - if (ret) - goto out_cleanup_connect_q; - - if (!new) { - nvme_start_queues(ctrl); + } else if (prior_q_cnt != ctrl->queue_count) { if (!nvme_wait_freeze_timeout(ctrl, NVME_IO_TIMEOUT)) { /* * If we timed out waiting for freeze we are likely to @@ -1828,6 +1822,10 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) nvme_unfreeze(ctrl); } + ret = nvme_tcp_start_io_queues(ctrl); + if (ret) + goto out_cleanup_connect_q; + return 0; out_wait_freeze_timed_out: -- 2.29.2 _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme ^ permalink raw reply related [flat|nested] 23+ messages in thread
* Re: [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them 2021-08-02 11:26 ` Daniel Wagner @ 2021-08-06 19:57 ` Sagi Grimberg -1 siblings, 0 replies; 23+ messages in thread From: Sagi Grimberg @ 2021-08-06 19:57 UTC (permalink / raw) To: Daniel Wagner, linux-nvme Cc: linux-kernel, James Smart, Keith Busch, Ming Lei, Hannes Reinecke, Wen Xiong > From: Hannes Reinecke <hare@suse.de> > > When the number of hardware queues changes during resetting we should > update the tagset first before using it. > > Signed-off-by: Hannes Reinecke <hare@suse.de> > Signed-off-by: Daniel Wagner <dwagner@suse.de> > --- > drivers/nvme/host/tcp.c | 14 ++++++-------- > 1 file changed, 6 insertions(+), 8 deletions(-) > > diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c > index 0a97ba02f61e..32268f24f62a 100644 > --- a/drivers/nvme/host/tcp.c > +++ b/drivers/nvme/host/tcp.c > @@ -1789,6 +1789,7 @@ static void nvme_tcp_destroy_io_queues(struct nvme_ctrl *ctrl, bool remove) > static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) > { > int ret; > + u32 prior_q_cnt = ctrl->queue_count; > > ret = nvme_tcp_alloc_io_queues(ctrl); > if (ret) > @@ -1806,14 +1807,7 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) > ret = PTR_ERR(ctrl->connect_q); > goto out_free_tag_set; > } > - } > - > - ret = nvme_tcp_start_io_queues(ctrl); > - if (ret) > - goto out_cleanup_connect_q; > - > - if (!new) { > - nvme_start_queues(ctrl); > + } else if (prior_q_cnt != ctrl->queue_count) { So if the queue count did not change we don't wait to make sure the queue g_usage_counter ref made it to zero? What guarantees that it did? > if (!nvme_wait_freeze_timeout(ctrl, NVME_IO_TIMEOUT)) { > /* > * If we timed out waiting for freeze we are likely to > @@ -1828,6 +1822,10 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) > nvme_unfreeze(ctrl); > } > > + ret = nvme_tcp_start_io_queues(ctrl); > + if (ret) > + goto out_cleanup_connect_q; > + Did you test this with both heavy I/O, reset loop and ifdown/ifup loop? If we unquiesce and unfreeze before we start the queues the pending I/Os may resume before the connect and not allow the connect to make forward progress. > return 0; > > out_wait_freeze_timed_out: > ^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them @ 2021-08-06 19:57 ` Sagi Grimberg 0 siblings, 0 replies; 23+ messages in thread From: Sagi Grimberg @ 2021-08-06 19:57 UTC (permalink / raw) To: Daniel Wagner, linux-nvme Cc: linux-kernel, James Smart, Keith Busch, Ming Lei, Hannes Reinecke, Wen Xiong > From: Hannes Reinecke <hare@suse.de> > > When the number of hardware queues changes during resetting we should > update the tagset first before using it. > > Signed-off-by: Hannes Reinecke <hare@suse.de> > Signed-off-by: Daniel Wagner <dwagner@suse.de> > --- > drivers/nvme/host/tcp.c | 14 ++++++-------- > 1 file changed, 6 insertions(+), 8 deletions(-) > > diff --git a/drivers/nvme/host/tcp.c b/drivers/nvme/host/tcp.c > index 0a97ba02f61e..32268f24f62a 100644 > --- a/drivers/nvme/host/tcp.c > +++ b/drivers/nvme/host/tcp.c > @@ -1789,6 +1789,7 @@ static void nvme_tcp_destroy_io_queues(struct nvme_ctrl *ctrl, bool remove) > static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) > { > int ret; > + u32 prior_q_cnt = ctrl->queue_count; > > ret = nvme_tcp_alloc_io_queues(ctrl); > if (ret) > @@ -1806,14 +1807,7 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) > ret = PTR_ERR(ctrl->connect_q); > goto out_free_tag_set; > } > - } > - > - ret = nvme_tcp_start_io_queues(ctrl); > - if (ret) > - goto out_cleanup_connect_q; > - > - if (!new) { > - nvme_start_queues(ctrl); > + } else if (prior_q_cnt != ctrl->queue_count) { So if the queue count did not change we don't wait to make sure the queue g_usage_counter ref made it to zero? What guarantees that it did? > if (!nvme_wait_freeze_timeout(ctrl, NVME_IO_TIMEOUT)) { > /* > * If we timed out waiting for freeze we are likely to > @@ -1828,6 +1822,10 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) > nvme_unfreeze(ctrl); > } > > + ret = nvme_tcp_start_io_queues(ctrl); > + if (ret) > + goto out_cleanup_connect_q; > + Did you test this with both heavy I/O, reset loop and ifdown/ifup loop? If we unquiesce and unfreeze before we start the queues the pending I/Os may resume before the connect and not allow the connect to make forward progress. > return 0; > > out_wait_freeze_timed_out: > _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme ^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them 2021-08-06 19:57 ` Sagi Grimberg @ 2021-08-09 8:52 ` Daniel Wagner -1 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-09 8:52 UTC (permalink / raw) To: Sagi Grimberg Cc: linux-nvme, linux-kernel, James Smart, Keith Busch, Ming Lei, Hannes Reinecke, Wen Xiong Hi Sagi, On Fri, Aug 06, 2021 at 12:57:17PM -0700, Sagi Grimberg wrote: > > - ret = nvme_tcp_start_io_queues(ctrl); > > - if (ret) > > - goto out_cleanup_connect_q; > > - > > - if (!new) { > > - nvme_start_queues(ctrl); > > + } else if (prior_q_cnt != ctrl->queue_count) { > > So if the queue count did not change we don't wait to make sure > the queue g_usage_counter ref made it to zero? What guarantees that it > did? Hmm, good point. we should always call nvme_wait_freeze_timeout() for !new queues. Is this what you are implying? > > if (!nvme_wait_freeze_timeout(ctrl, NVME_IO_TIMEOUT)) { > > /* > > * If we timed out waiting for freeze we are likely to > > @@ -1828,6 +1822,10 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) > > nvme_unfreeze(ctrl); > > } > > + ret = nvme_tcp_start_io_queues(ctrl); > > + if (ret) > > + goto out_cleanup_connect_q; > > + > > Did you test this with both heavy I/O, reset loop and ifdown/ifup > loop? Not sure if this classifies as heavy I/O (on 80 CPU machine) fio --rw=readwrite --name=test --filename=/dev/nvme16n1 --size=50M \ --direct=1 --bs=4k --numjobs=40 --group_reporting --runtime=4h \ --time_based and then I installed iptables rules to block the traffic on the controller side. With this test it is pretty easily to get the host hanging. Let me know what test you would like to see from me. I am glad to try to get them running. > If we unquiesce and unfreeze before we start the queues the pending I/Os > may resume before the connect and not allow the connect to make forward > progress. So the unfreeze should happen after the connect call? What about the newly created queues? Do they not suffer from the same problem? Isn't the NVME_TCP_Q_LIVE flag not enough? Daniel ^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them @ 2021-08-09 8:52 ` Daniel Wagner 0 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-09 8:52 UTC (permalink / raw) To: Sagi Grimberg Cc: linux-nvme, linux-kernel, James Smart, Keith Busch, Ming Lei, Hannes Reinecke, Wen Xiong Hi Sagi, On Fri, Aug 06, 2021 at 12:57:17PM -0700, Sagi Grimberg wrote: > > - ret = nvme_tcp_start_io_queues(ctrl); > > - if (ret) > > - goto out_cleanup_connect_q; > > - > > - if (!new) { > > - nvme_start_queues(ctrl); > > + } else if (prior_q_cnt != ctrl->queue_count) { > > So if the queue count did not change we don't wait to make sure > the queue g_usage_counter ref made it to zero? What guarantees that it > did? Hmm, good point. we should always call nvme_wait_freeze_timeout() for !new queues. Is this what you are implying? > > if (!nvme_wait_freeze_timeout(ctrl, NVME_IO_TIMEOUT)) { > > /* > > * If we timed out waiting for freeze we are likely to > > @@ -1828,6 +1822,10 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) > > nvme_unfreeze(ctrl); > > } > > + ret = nvme_tcp_start_io_queues(ctrl); > > + if (ret) > > + goto out_cleanup_connect_q; > > + > > Did you test this with both heavy I/O, reset loop and ifdown/ifup > loop? Not sure if this classifies as heavy I/O (on 80 CPU machine) fio --rw=readwrite --name=test --filename=/dev/nvme16n1 --size=50M \ --direct=1 --bs=4k --numjobs=40 --group_reporting --runtime=4h \ --time_based and then I installed iptables rules to block the traffic on the controller side. With this test it is pretty easily to get the host hanging. Let me know what test you would like to see from me. I am glad to try to get them running. > If we unquiesce and unfreeze before we start the queues the pending I/Os > may resume before the connect and not allow the connect to make forward > progress. So the unfreeze should happen after the connect call? What about the newly created queues? Do they not suffer from the same problem? Isn't the NVME_TCP_Q_LIVE flag not enough? Daniel _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme ^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them 2021-08-09 8:52 ` Daniel Wagner @ 2021-08-11 1:00 ` Sagi Grimberg -1 siblings, 0 replies; 23+ messages in thread From: Sagi Grimberg @ 2021-08-11 1:00 UTC (permalink / raw) To: Daniel Wagner Cc: linux-nvme, linux-kernel, James Smart, Keith Busch, Ming Lei, Hannes Reinecke, Wen Xiong On 8/9/21 1:52 AM, Daniel Wagner wrote: > Hi Sagi, > > On Fri, Aug 06, 2021 at 12:57:17PM -0700, Sagi Grimberg wrote: >>> - ret = nvme_tcp_start_io_queues(ctrl); >>> - if (ret) >>> - goto out_cleanup_connect_q; >>> - >>> - if (!new) { >>> - nvme_start_queues(ctrl); >>> + } else if (prior_q_cnt != ctrl->queue_count) { >> >> So if the queue count did not change we don't wait to make sure >> the queue g_usage_counter ref made it to zero? What guarantees that it >> did? > > Hmm, good point. we should always call nvme_wait_freeze_timeout() > for !new queues. Is this what you are implying? I think we should always wait for the freeze to complete. > > >>> if (!nvme_wait_freeze_timeout(ctrl, NVME_IO_TIMEOUT)) { >>> /* >>> * If we timed out waiting for freeze we are likely to >>> @@ -1828,6 +1822,10 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) >>> nvme_unfreeze(ctrl); >>> } >>> + ret = nvme_tcp_start_io_queues(ctrl); >>> + if (ret) >>> + goto out_cleanup_connect_q; >>> + >> >> Did you test this with both heavy I/O, reset loop and ifdown/ifup >> loop? > > Not sure if this classifies as heavy I/O (on 80 CPU machine) > > fio --rw=readwrite --name=test --filename=/dev/nvme16n1 --size=50M \ > --direct=1 --bs=4k --numjobs=40 --group_reporting --runtime=4h \ > --time_based > > and then I installed iptables rules to block the traffic on the > controller side. With this test it is pretty easily to get > the host hanging. Let me know what test you would like to see > from me. I am glad to try to get them running. Lets add iodepth=128 >> If we unquiesce and unfreeze before we start the queues the pending I/Os >> may resume before the connect and not allow the connect to make forward >> progress. > > So the unfreeze should happen after the connect call? What about the > newly created queues? Do they not suffer from the same problem? Isn't > the NVME_TCP_Q_LIVE flag not enough? Q_LIVE will protect against the transport itself from queueing, however when multipath is not used, the transport will return BLK_STS_RESOURCE which will immediately trigger re-submission, in an endless loop, and that can prevent forward progress. It is also consistent with what nvme-pci does. ^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them @ 2021-08-11 1:00 ` Sagi Grimberg 0 siblings, 0 replies; 23+ messages in thread From: Sagi Grimberg @ 2021-08-11 1:00 UTC (permalink / raw) To: Daniel Wagner Cc: linux-nvme, linux-kernel, James Smart, Keith Busch, Ming Lei, Hannes Reinecke, Wen Xiong On 8/9/21 1:52 AM, Daniel Wagner wrote: > Hi Sagi, > > On Fri, Aug 06, 2021 at 12:57:17PM -0700, Sagi Grimberg wrote: >>> - ret = nvme_tcp_start_io_queues(ctrl); >>> - if (ret) >>> - goto out_cleanup_connect_q; >>> - >>> - if (!new) { >>> - nvme_start_queues(ctrl); >>> + } else if (prior_q_cnt != ctrl->queue_count) { >> >> So if the queue count did not change we don't wait to make sure >> the queue g_usage_counter ref made it to zero? What guarantees that it >> did? > > Hmm, good point. we should always call nvme_wait_freeze_timeout() > for !new queues. Is this what you are implying? I think we should always wait for the freeze to complete. > > >>> if (!nvme_wait_freeze_timeout(ctrl, NVME_IO_TIMEOUT)) { >>> /* >>> * If we timed out waiting for freeze we are likely to >>> @@ -1828,6 +1822,10 @@ static int nvme_tcp_configure_io_queues(struct nvme_ctrl *ctrl, bool new) >>> nvme_unfreeze(ctrl); >>> } >>> + ret = nvme_tcp_start_io_queues(ctrl); >>> + if (ret) >>> + goto out_cleanup_connect_q; >>> + >> >> Did you test this with both heavy I/O, reset loop and ifdown/ifup >> loop? > > Not sure if this classifies as heavy I/O (on 80 CPU machine) > > fio --rw=readwrite --name=test --filename=/dev/nvme16n1 --size=50M \ > --direct=1 --bs=4k --numjobs=40 --group_reporting --runtime=4h \ > --time_based > > and then I installed iptables rules to block the traffic on the > controller side. With this test it is pretty easily to get > the host hanging. Let me know what test you would like to see > from me. I am glad to try to get them running. Lets add iodepth=128 >> If we unquiesce and unfreeze before we start the queues the pending I/Os >> may resume before the connect and not allow the connect to make forward >> progress. > > So the unfreeze should happen after the connect call? What about the > newly created queues? Do they not suffer from the same problem? Isn't > the NVME_TCP_Q_LIVE flag not enough? Q_LIVE will protect against the transport itself from queueing, however when multipath is not used, the transport will return BLK_STS_RESOURCE which will immediately trigger re-submission, in an endless loop, and that can prevent forward progress. It is also consistent with what nvme-pci does. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme ^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them 2021-08-11 1:00 ` Sagi Grimberg @ 2021-08-11 1:07 ` Keith Busch -1 siblings, 0 replies; 23+ messages in thread From: Keith Busch @ 2021-08-11 1:07 UTC (permalink / raw) To: Sagi Grimberg Cc: Daniel Wagner, linux-nvme, linux-kernel, James Smart, Ming Lei, Hannes Reinecke, Wen Xiong On Tue, Aug 10, 2021 at 06:00:37PM -0700, Sagi Grimberg wrote: > > > On 8/9/21 1:52 AM, Daniel Wagner wrote: > > Hi Sagi, > > > > On Fri, Aug 06, 2021 at 12:57:17PM -0700, Sagi Grimberg wrote: > > > > - ret = nvme_tcp_start_io_queues(ctrl); > > > > - if (ret) > > > > - goto out_cleanup_connect_q; > > > > - > > > > - if (!new) { > > > > - nvme_start_queues(ctrl); > > > > + } else if (prior_q_cnt != ctrl->queue_count) { > > > > > > So if the queue count did not change we don't wait to make sure > > > the queue g_usage_counter ref made it to zero? What guarantees that it > > > did? > > > > Hmm, good point. we should always call nvme_wait_freeze_timeout() > > for !new queues. Is this what you are implying? > > I think we should always wait for the freeze to complete. Don't the queues need to be started in order for the freeze to complete? Any enqueued requests on the quiesced queues will never complete this way, so the wait_freeze() will be stuck, right? If so, I think the nvme_start_queues() was in the correct place already. ^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them @ 2021-08-11 1:07 ` Keith Busch 0 siblings, 0 replies; 23+ messages in thread From: Keith Busch @ 2021-08-11 1:07 UTC (permalink / raw) To: Sagi Grimberg Cc: Daniel Wagner, linux-nvme, linux-kernel, James Smart, Ming Lei, Hannes Reinecke, Wen Xiong On Tue, Aug 10, 2021 at 06:00:37PM -0700, Sagi Grimberg wrote: > > > On 8/9/21 1:52 AM, Daniel Wagner wrote: > > Hi Sagi, > > > > On Fri, Aug 06, 2021 at 12:57:17PM -0700, Sagi Grimberg wrote: > > > > - ret = nvme_tcp_start_io_queues(ctrl); > > > > - if (ret) > > > > - goto out_cleanup_connect_q; > > > > - > > > > - if (!new) { > > > > - nvme_start_queues(ctrl); > > > > + } else if (prior_q_cnt != ctrl->queue_count) { > > > > > > So if the queue count did not change we don't wait to make sure > > > the queue g_usage_counter ref made it to zero? What guarantees that it > > > did? > > > > Hmm, good point. we should always call nvme_wait_freeze_timeout() > > for !new queues. Is this what you are implying? > > I think we should always wait for the freeze to complete. Don't the queues need to be started in order for the freeze to complete? Any enqueued requests on the quiesced queues will never complete this way, so the wait_freeze() will be stuck, right? If so, I think the nvme_start_queues() was in the correct place already. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme ^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them 2021-08-11 1:07 ` Keith Busch @ 2021-08-11 5:57 ` Sagi Grimberg -1 siblings, 0 replies; 23+ messages in thread From: Sagi Grimberg @ 2021-08-11 5:57 UTC (permalink / raw) To: Keith Busch Cc: Daniel Wagner, linux-nvme, linux-kernel, James Smart, Ming Lei, Hannes Reinecke, Wen Xiong >> On 8/9/21 1:52 AM, Daniel Wagner wrote: >>> Hi Sagi, >>> >>> On Fri, Aug 06, 2021 at 12:57:17PM -0700, Sagi Grimberg wrote: >>>>> - ret = nvme_tcp_start_io_queues(ctrl); >>>>> - if (ret) >>>>> - goto out_cleanup_connect_q; >>>>> - >>>>> - if (!new) { >>>>> - nvme_start_queues(ctrl); >>>>> + } else if (prior_q_cnt != ctrl->queue_count) { >>>> >>>> So if the queue count did not change we don't wait to make sure >>>> the queue g_usage_counter ref made it to zero? What guarantees that it >>>> did? >>> >>> Hmm, good point. we should always call nvme_wait_freeze_timeout() >>> for !new queues. Is this what you are implying? >> >> I think we should always wait for the freeze to complete. > > Don't the queues need to be started in order for the freeze to complete? > Any enqueued requests on the quiesced queues will never complete this > way, so the wait_freeze() will be stuck, right? If so, I think the > nvme_start_queues() was in the correct place already. Exactly what I was trying to point out (poorly though) ^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them @ 2021-08-11 5:57 ` Sagi Grimberg 0 siblings, 0 replies; 23+ messages in thread From: Sagi Grimberg @ 2021-08-11 5:57 UTC (permalink / raw) To: Keith Busch Cc: Daniel Wagner, linux-nvme, linux-kernel, James Smart, Ming Lei, Hannes Reinecke, Wen Xiong >> On 8/9/21 1:52 AM, Daniel Wagner wrote: >>> Hi Sagi, >>> >>> On Fri, Aug 06, 2021 at 12:57:17PM -0700, Sagi Grimberg wrote: >>>>> - ret = nvme_tcp_start_io_queues(ctrl); >>>>> - if (ret) >>>>> - goto out_cleanup_connect_q; >>>>> - >>>>> - if (!new) { >>>>> - nvme_start_queues(ctrl); >>>>> + } else if (prior_q_cnt != ctrl->queue_count) { >>>> >>>> So if the queue count did not change we don't wait to make sure >>>> the queue g_usage_counter ref made it to zero? What guarantees that it >>>> did? >>> >>> Hmm, good point. we should always call nvme_wait_freeze_timeout() >>> for !new queues. Is this what you are implying? >> >> I think we should always wait for the freeze to complete. > > Don't the queues need to be started in order for the freeze to complete? > Any enqueued requests on the quiesced queues will never complete this > way, so the wait_freeze() will be stuck, right? If so, I think the > nvme_start_queues() was in the correct place already. Exactly what I was trying to point out (poorly though) _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme ^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them 2021-08-11 5:57 ` Sagi Grimberg @ 2021-08-11 10:25 ` Daniel Wagner -1 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-11 10:25 UTC (permalink / raw) To: Sagi Grimberg Cc: Keith Busch, linux-nvme, linux-kernel, James Smart, Ming Lei, Hannes Reinecke, Wen Xiong On Tue, Aug 10, 2021 at 10:57:58PM -0700, Sagi Grimberg wrote: > > > I think we should always wait for the freeze to complete. > > > > Don't the queues need to be started in order for the freeze to complete? > > Any enqueued requests on the quiesced queues will never complete this > > way, so the wait_freeze() will be stuck, right? If so, I think the > > nvme_start_queues() was in the correct place already. > > Exactly what I was trying to point out (poorly though) Thanks for explaining. I think I got the general idea what the different states are doing and what the transitions are now. (famous last words). Anyway, the first three patches are the result of debugging the case of 'prior_ioq_cnt != nr_io_queues'. Starting the queues before updating the number of queues lookes strange. I suppose in the case 'prior_ioq_cnt > nr_io_queues', nvme_tcp_start_io_queues() should be successful and we do the blk_mq_update_nr_hw_queues(). In the other case we should land in the error recovery. Wouldn't it make sense to always exercise the error recovery path if we detect 'prior_ioq_cnt != nr_io_queues' and reduce the number of things which can go wrong? Daniel ^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them @ 2021-08-11 10:25 ` Daniel Wagner 0 siblings, 0 replies; 23+ messages in thread From: Daniel Wagner @ 2021-08-11 10:25 UTC (permalink / raw) To: Sagi Grimberg Cc: Keith Busch, linux-nvme, linux-kernel, James Smart, Ming Lei, Hannes Reinecke, Wen Xiong On Tue, Aug 10, 2021 at 10:57:58PM -0700, Sagi Grimberg wrote: > > > I think we should always wait for the freeze to complete. > > > > Don't the queues need to be started in order for the freeze to complete? > > Any enqueued requests on the quiesced queues will never complete this > > way, so the wait_freeze() will be stuck, right? If so, I think the > > nvme_start_queues() was in the correct place already. > > Exactly what I was trying to point out (poorly though) Thanks for explaining. I think I got the general idea what the different states are doing and what the transitions are now. (famous last words). Anyway, the first three patches are the result of debugging the case of 'prior_ioq_cnt != nr_io_queues'. Starting the queues before updating the number of queues lookes strange. I suppose in the case 'prior_ioq_cnt > nr_io_queues', nvme_tcp_start_io_queues() should be successful and we do the blk_mq_update_nr_hw_queues(). In the other case we should land in the error recovery. Wouldn't it make sense to always exercise the error recovery path if we detect 'prior_ioq_cnt != nr_io_queues' and reduce the number of things which can go wrong? Daniel _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme ^ permalink raw reply [flat|nested] 23+ messages in thread
end of thread, other threads:[~2021-08-11 10:27 UTC | newest] Thread overview: 23+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-08-02 9:14 [PATCH v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 1/8] nvme-fc: Update hardware queues before using them Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 2/8] nvme-tcp: Update number of " Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 3/8] nvme-rdma: " Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 4/8] nvme-fc: Wait with a timeout for queue to freeze Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 5/8] nvme-fc: avoid race between time out and tear down Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 6/8] nvme-fc: fix controller reset hang during traffic Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 7/8] nvme-tcp: Unfreeze queues on reconnect Daniel Wagner 2021-08-02 9:14 ` [PATCH v4 8/8] nvme-rdma: " Daniel Wagner 2021-08-02 11:26 [PATCH RESEND v4 0/8] Handle update hardware queues and queue freeze more carefully Daniel Wagner 2021-08-02 11:26 ` [PATCH v4 2/8] nvme-tcp: Update number of hardware queues before using them Daniel Wagner 2021-08-02 11:26 ` Daniel Wagner 2021-08-06 19:57 ` Sagi Grimberg 2021-08-06 19:57 ` Sagi Grimberg 2021-08-09 8:52 ` Daniel Wagner 2021-08-09 8:52 ` Daniel Wagner 2021-08-11 1:00 ` Sagi Grimberg 2021-08-11 1:00 ` Sagi Grimberg 2021-08-11 1:07 ` Keith Busch 2021-08-11 1:07 ` Keith Busch 2021-08-11 5:57 ` Sagi Grimberg 2021-08-11 5:57 ` Sagi Grimberg 2021-08-11 10:25 ` Daniel Wagner 2021-08-11 10:25 ` Daniel Wagner
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.