linux/drivers/infiniband/core/cq.c

518 lines
13 KiB

RDMA/core: Introduce shared CQ pool API Allow a ULP to ask the core to provide a completion queue based on a least-used search on a per-device CQ pools. The device CQ pools grow in a lazy fashion when more CQs are requested. This feature reduces the amount of interrupts when using many QPs. Using shared CQs allows for more effcient completion handling. It also reduces the amount of overhead needed for CQ contexts. Test setup: Intel(R) Xeon(R) Platinum 8176M CPU @ 2.10GHz servers. Running NVMeoF 4KB read IOs over ConnectX-5EX across Spectrum switch. TX-depth = 32. The patch was applied in the nvme driver on both the target and initiator. Four controllers are accessed from each core. In the current test case we have exposed sixteen NVMe namespaces using four different subsystems (four namespaces per subsystem) from one NVM port. Each controller allocated X queues (RDMA QPs) and attached to Y CQs. Before this series we had X == Y, i.e for four controllers we've created total of 4X QPs and 4X CQs. In the shared case, we've created 4X QPs and only X CQs which means that we have four controllers that share a completion queue per core. Until fourteen cores there is no significant change in performance and the number of interrupts per second is less than a million in the current case. ================================================== |Cores|Current KIOPs |Shared KIOPs |improvement| |-----|---------------|--------------|-----------| |14 |2332 |2723 |16.7% | |-----|---------------|--------------|-----------| |20 |2086 |2712 |30% | |-----|---------------|--------------|-----------| |28 |1971 |2669 |35.4% | |================================================= |Cores|Current avg lat|Shared avg lat|improvement| |-----|---------------|--------------|-----------| |14 |767us |657us |14.3% | |-----|---------------|--------------|-----------| |20 |1225us |943us |23% | |-----|---------------|--------------|-----------| |28 |1816us |1341us |26.1% | ======================================================== |Cores|Current interrupts|Shared interrupts|improvement| |-----|------------------|-----------------|-----------| |14 |1.6M/sec |0.4M/sec |72% | |-----|------------------|-----------------|-----------| |20 |2.8M/sec |0.6M/sec |72.4% | |-----|------------------|-----------------|-----------| |28 |2.9M/sec |0.8M/sec |63.4% | ==================================================================== |Cores|Current 99.99th PCTL lat|Shared 99.99th PCTL lat|improvement| |-----|------------------------|-----------------------|-----------| |14 |67ms |6ms |90.9% | |-----|------------------------|-----------------------|-----------| |20 |5ms |6ms |-10% | |-----|------------------------|-----------------------|-----------| |28 |8.7ms |6ms |25.9% | |=================================================================== Performance improvement with sixteen disks (sixteen CQs per core) is comparable. Link: https://lore.kernel.org/r/1590568495-101621-3-git-send-email-yaminf@mellanox.com Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-27 11:34:53 +03:00
RDMA/core: Trace points for diagnosing completion queue issues Sample trace events: kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE <idle>-0 [002] 120.056292: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067503: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067657: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1 ... systemd-1 [002] 122.392653: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3 Several features to note in this output: - The WCE count and context type are reported at allocation time - The CPU and kworker for each CQ is evident - The CQ's restracker ID is tagged on each trace event - CQ poll scheduling latency is measured - Details about how often single completions occur versus multiple completions are evident - The cost of the ULP's completion handler is recorded Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-12-18 15:18:15 -05:00
RDMA/core: Introduce shared CQ pool API Allow a ULP to ask the core to provide a completion queue based on a least-used search on a per-device CQ pools. The device CQ pools grow in a lazy fashion when more CQs are requested. This feature reduces the amount of interrupts when using many QPs. Using shared CQs allows for more effcient completion handling. It also reduces the amount of overhead needed for CQ contexts. Test setup: Intel(R) Xeon(R) Platinum 8176M CPU @ 2.10GHz servers. Running NVMeoF 4KB read IOs over ConnectX-5EX across Spectrum switch. TX-depth = 32. The patch was applied in the nvme driver on both the target and initiator. Four controllers are accessed from each core. In the current test case we have exposed sixteen NVMe namespaces using four different subsystems (four namespaces per subsystem) from one NVM port. Each controller allocated X queues (RDMA QPs) and attached to Y CQs. Before this series we had X == Y, i.e for four controllers we've created total of 4X QPs and 4X CQs. In the shared case, we've created 4X QPs and only X CQs which means that we have four controllers that share a completion queue per core. Until fourteen cores there is no significant change in performance and the number of interrupts per second is less than a million in the current case. ================================================== |Cores|Current KIOPs |Shared KIOPs |improvement| |-----|---------------|--------------|-----------| |14 |2332 |2723 |16.7% | |-----|---------------|--------------|-----------| |20 |2086 |2712 |30% | |-----|---------------|--------------|-----------| |28 |1971 |2669 |35.4% | |================================================= |Cores|Current avg lat|Shared avg lat|improvement| |-----|---------------|--------------|-----------| |14 |767us |657us |14.3% | |-----|---------------|--------------|-----------| |20 |1225us |943us |23% | |-----|---------------|--------------|-----------| |28 |1816us |1341us |26.1% | ======================================================== |Cores|Current interrupts|Shared interrupts|improvement| |-----|------------------|-----------------|-----------| |14 |1.6M/sec |0.4M/sec |72% | |-----|------------------|-----------------|-----------| |20 |2.8M/sec |0.6M/sec |72.4% | |-----|------------------|-----------------|-----------| |28 |2.9M/sec |0.8M/sec |63.4% | ==================================================================== |Cores|Current 99.99th PCTL lat|Shared 99.99th PCTL lat|improvement| |-----|------------------------|-----------------------|-----------| |14 |67ms |6ms |90.9% | |-----|------------------------|-----------------------|-----------| |20 |5ms |6ms |-10% | |-----|------------------------|-----------------------|-----------| |28 |8.7ms |6ms |25.9% | |=================================================================== Performance improvement with sixteen disks (sixteen CQs per core) is comparable. Link: https://lore.kernel.org/r/1590568495-101621-3-git-send-email-yaminf@mellanox.com Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-27 11:34:53 +03:00
RDMA/core: Trace points for diagnosing completion queue issues Sample trace events: kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE <idle>-0 [002] 120.056292: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067503: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067657: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1 ... systemd-1 [002] 122.392653: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3 Several features to note in this output: - The WCE count and context type are reported at allocation time - The CPU and kworker for each CQ is evident - The CQ's restracker ID is tagged on each trace event - CQ poll scheduling latency is measured - Details about how often single completions occur versus multiple completions are evident - The cost of the ULP's completion handler is recorded Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-12-18 15:18:15 -05:00
RDMA/core: Provide RDMA DIM support for ULPs Added the interface in the infiniband driver that applies the rdma_dim adaptive moderation. There is now a special function for allocating an ib_cq that uses rdma_dim. Performance improvement (ConnectX-5 100GbE, x86) running FIO benchmark over NVMf between two equal end-hosts with 56 cores across a Mellanox switch using null_blk device: READS without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.8GiB/s | 7.7M | 1401 usec | 2442 usec 4k | 7.0GiB/s | 1.8M | 4817 usec | 6587 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.6GiB/s | 7.5M | 1434 usec | 2474 usec 4k | 6.3GiB/s | 1.6M | 938 usec | 1221 usec 64k | 10.7GiB/s| 175k | 8979 usec | 12780 usec IO READS with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 4GiB/s | 8.2M | 816 usec | 889 usec 4k | 10.1GiB/s| 2.65M| 3359 usec | 5080 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.9GiB/s | 8.1M | 799 usec | 922 usec 4k | 9.6GiB/s | 2.5M | 717 usec | 1004 usec 64k | 10.7GiB/s| 176k | 8586 usec | 12256 usec The rdma_dim algorithm was designed to measure the effectiveness of moderation on the flow in a general way and thus should be appropriate for all RDMA storage protocols. rdma_dim is configured to be the default option based on performance improvement seen after extensive tests. Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-07-08 13:59:03 +03:00
RDMA/core: Trace points for diagnosing completion queue issues Sample trace events: kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE <idle>-0 [002] 120.056292: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067503: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067657: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1 ... systemd-1 [002] 122.392653: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3 Several features to note in this output: - The WCE count and context type are reported at allocation time - The CPU and kworker for each CQ is evident - The CQ's restracker ID is tagged on each trace event - CQ poll scheduling latency is measured - Details about how often single completions occur versus multiple completions are evident - The cost of the ULP's completion handler is recorded Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-12-18 15:18:15 -05:00
RDMA/core: Provide RDMA DIM support for ULPs Added the interface in the infiniband driver that applies the rdma_dim adaptive moderation. There is now a special function for allocating an ib_cq that uses rdma_dim. Performance improvement (ConnectX-5 100GbE, x86) running FIO benchmark over NVMf between two equal end-hosts with 56 cores across a Mellanox switch using null_blk device: READS without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.8GiB/s | 7.7M | 1401 usec | 2442 usec 4k | 7.0GiB/s | 1.8M | 4817 usec | 6587 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.6GiB/s | 7.5M | 1434 usec | 2474 usec 4k | 6.3GiB/s | 1.6M | 938 usec | 1221 usec 64k | 10.7GiB/s| 175k | 8979 usec | 12780 usec IO READS with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 4GiB/s | 8.2M | 816 usec | 889 usec 4k | 10.1GiB/s| 2.65M| 3359 usec | 5080 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.9GiB/s | 8.1M | 799 usec | 922 usec 4k | 9.6GiB/s | 2.5M | 717 usec | 1004 usec 64k | 10.7GiB/s| 176k | 8586 usec | 12256 usec The rdma_dim algorithm was designed to measure the effectiveness of moderation on the flow in a general way and thus should be appropriate for all RDMA storage protocols. rdma_dim is configured to be the default option based on performance improvement seen after extensive tests. Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-07-08 13:59:03 +03:00
RDMA/core: Provide RDMA DIM support for ULPs Added the interface in the infiniband driver that applies the rdma_dim adaptive moderation. There is now a special function for allocating an ib_cq that uses rdma_dim. Performance improvement (ConnectX-5 100GbE, x86) running FIO benchmark over NVMf between two equal end-hosts with 56 cores across a Mellanox switch using null_blk device: READS without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.8GiB/s | 7.7M | 1401 usec | 2442 usec 4k | 7.0GiB/s | 1.8M | 4817 usec | 6587 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.6GiB/s | 7.5M | 1434 usec | 2474 usec 4k | 6.3GiB/s | 1.6M | 938 usec | 1221 usec 64k | 10.7GiB/s| 175k | 8979 usec | 12780 usec IO READS with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 4GiB/s | 8.2M | 816 usec | 889 usec 4k | 10.1GiB/s| 2.65M| 3359 usec | 5080 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.9GiB/s | 8.1M | 799 usec | 922 usec 4k | 9.6GiB/s | 2.5M | 717 usec | 1004 usec 64k | 10.7GiB/s| 176k | 8586 usec | 12256 usec The rdma_dim algorithm was designed to measure the effectiveness of moderation on the flow in a general way and thus should be appropriate for all RDMA storage protocols. rdma_dim is configured to be the default option based on performance improvement seen after extensive tests. Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-07-08 13:59:03 +03:00
RDMA/core: Trace points for diagnosing completion queue issues Sample trace events: kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE <idle>-0 [002] 120.056292: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067503: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067657: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1 ... systemd-1 [002] 122.392653: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3 Several features to note in this output: - The WCE count and context type are reported at allocation time - The CPU and kworker for each CQ is evident - The CQ's restracker ID is tagged on each trace event - CQ poll scheduling latency is measured - Details about how often single completions occur versus multiple completions are evident - The cost of the ULP's completion handler is recorded Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-12-18 15:18:15 -05:00
RDMA/core: Trace points for diagnosing completion queue issues Sample trace events: kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE <idle>-0 [002] 120.056292: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067503: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067657: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1 ... systemd-1 [002] 122.392653: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3 Several features to note in this output: - The WCE count and context type are reported at allocation time - The CPU and kworker for each CQ is evident - The CQ's restracker ID is tagged on each trace event - CQ poll scheduling latency is measured - Details about how often single completions occur versus multiple completions are evident - The cost of the ULP's completion handler is recorded Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-12-18 15:18:15 -05:00
RDMA/core: Trace points for diagnosing completion queue issues Sample trace events: kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE <idle>-0 [002] 120.056292: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067503: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067657: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1 ... systemd-1 [002] 122.392653: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3 Several features to note in this output: - The WCE count and context type are reported at allocation time - The CPU and kworker for each CQ is evident - The CQ's restracker ID is tagged on each trace event - CQ poll scheduling latency is measured - Details about how often single completions occur versus multiple completions are evident - The cost of the ULP's completion handler is recorded Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-12-18 15:18:15 -05:00
RDMA/core: Provide RDMA DIM support for ULPs Added the interface in the infiniband driver that applies the rdma_dim adaptive moderation. There is now a special function for allocating an ib_cq that uses rdma_dim. Performance improvement (ConnectX-5 100GbE, x86) running FIO benchmark over NVMf between two equal end-hosts with 56 cores across a Mellanox switch using null_blk device: READS without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.8GiB/s | 7.7M | 1401 usec | 2442 usec 4k | 7.0GiB/s | 1.8M | 4817 usec | 6587 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.6GiB/s | 7.5M | 1434 usec | 2474 usec 4k | 6.3GiB/s | 1.6M | 938 usec | 1221 usec 64k | 10.7GiB/s| 175k | 8979 usec | 12780 usec IO READS with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 4GiB/s | 8.2M | 816 usec | 889 usec 4k | 10.1GiB/s| 2.65M| 3359 usec | 5080 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.9GiB/s | 8.1M | 799 usec | 922 usec 4k | 9.6GiB/s | 2.5M | 717 usec | 1004 usec 64k | 10.7GiB/s| 176k | 8586 usec | 12256 usec The rdma_dim algorithm was designed to measure the effectiveness of moderation on the flow in a general way and thus should be appropriate for all RDMA storage protocols. rdma_dim is configured to be the default option based on performance improvement seen after extensive tests. Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-07-08 13:59:03 +03:00
RDMA/core: Trace points for diagnosing completion queue issues Sample trace events: kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE <idle>-0 [002] 120.056292: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067503: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067657: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1 ... systemd-1 [002] 122.392653: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3 Several features to note in this output: - The WCE count and context type are reported at allocation time - The CPU and kworker for each CQ is evident - The CQ's restracker ID is tagged on each trace event - CQ poll scheduling latency is measured - Details about how often single completions occur versus multiple completions are evident - The cost of the ULP's completion handler is recorded Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-12-18 15:18:15 -05:00
RDMA/core: Trace points for diagnosing completion queue issues Sample trace events: kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE <idle>-0 [002] 120.056292: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067503: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067657: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1 ... systemd-1 [002] 122.392653: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3 Several features to note in this output: - The WCE count and context type are reported at allocation time - The CPU and kworker for each CQ is evident - The CQ's restracker ID is tagged on each trace event - CQ poll scheduling latency is measured - Details about how often single completions occur versus multiple completions are evident - The cost of the ULP's completion handler is recorded Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-12-18 15:18:15 -05:00
RDMA/core: Provide RDMA DIM support for ULPs Added the interface in the infiniband driver that applies the rdma_dim adaptive moderation. There is now a special function for allocating an ib_cq that uses rdma_dim. Performance improvement (ConnectX-5 100GbE, x86) running FIO benchmark over NVMf between two equal end-hosts with 56 cores across a Mellanox switch using null_blk device: READS without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.8GiB/s | 7.7M | 1401 usec | 2442 usec 4k | 7.0GiB/s | 1.8M | 4817 usec | 6587 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.6GiB/s | 7.5M | 1434 usec | 2474 usec 4k | 6.3GiB/s | 1.6M | 938 usec | 1221 usec 64k | 10.7GiB/s| 175k | 8979 usec | 12780 usec IO READS with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 4GiB/s | 8.2M | 816 usec | 889 usec 4k | 10.1GiB/s| 2.65M| 3359 usec | 5080 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.9GiB/s | 8.1M | 799 usec | 922 usec 4k | 9.6GiB/s | 2.5M | 717 usec | 1004 usec 64k | 10.7GiB/s| 176k | 8586 usec | 12256 usec The rdma_dim algorithm was designed to measure the effectiveness of moderation on the flow in a general way and thus should be appropriate for all RDMA storage protocols. rdma_dim is configured to be the default option based on performance improvement seen after extensive tests. Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-07-08 13:59:03 +03:00
RDMA/core: Trace points for diagnosing completion queue issues Sample trace events: kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE <idle>-0 [002] 120.056292: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067503: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067657: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1 ... systemd-1 [002] 122.392653: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3 Several features to note in this output: - The WCE count and context type are reported at allocation time - The CPU and kworker for each CQ is evident - The CQ's restracker ID is tagged on each trace event - CQ poll scheduling latency is measured - Details about how often single completions occur versus multiple completions are evident - The cost of the ULP's completion handler is recorded Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-12-18 15:18:15 -05:00
RDMA/core: Provide RDMA DIM support for ULPs Added the interface in the infiniband driver that applies the rdma_dim adaptive moderation. There is now a special function for allocating an ib_cq that uses rdma_dim. Performance improvement (ConnectX-5 100GbE, x86) running FIO benchmark over NVMf between two equal end-hosts with 56 cores across a Mellanox switch using null_blk device: READS without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.8GiB/s | 7.7M | 1401 usec | 2442 usec 4k | 7.0GiB/s | 1.8M | 4817 usec | 6587 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.6GiB/s | 7.5M | 1434 usec | 2474 usec 4k | 6.3GiB/s | 1.6M | 938 usec | 1221 usec 64k | 10.7GiB/s| 175k | 8979 usec | 12780 usec IO READS with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 4GiB/s | 8.2M | 816 usec | 889 usec 4k | 10.1GiB/s| 2.65M| 3359 usec | 5080 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.9GiB/s | 8.1M | 799 usec | 922 usec 4k | 9.6GiB/s | 2.5M | 717 usec | 1004 usec 64k | 10.7GiB/s| 176k | 8586 usec | 12256 usec The rdma_dim algorithm was designed to measure the effectiveness of moderation on the flow in a general way and thus should be appropriate for all RDMA storage protocols. rdma_dim is configured to be the default option based on performance improvement seen after extensive tests. Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-07-08 13:59:03 +03:00
RDMA/core: Trace points for diagnosing completion queue issues Sample trace events: kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE <idle>-0 [002] 120.056292: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067503: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067657: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1 ... systemd-1 [002] 122.392653: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3 Several features to note in this output: - The WCE count and context type are reported at allocation time - The CPU and kworker for each CQ is evident - The CQ's restracker ID is tagged on each trace event - CQ poll scheduling latency is measured - Details about how often single completions occur versus multiple completions are evident - The cost of the ULP's completion handler is recorded Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-12-18 15:18:15 -05:00
RDMA/core: Introduce shared CQ pool API Allow a ULP to ask the core to provide a completion queue based on a least-used search on a per-device CQ pools. The device CQ pools grow in a lazy fashion when more CQs are requested. This feature reduces the amount of interrupts when using many QPs. Using shared CQs allows for more effcient completion handling. It also reduces the amount of overhead needed for CQ contexts. Test setup: Intel(R) Xeon(R) Platinum 8176M CPU @ 2.10GHz servers. Running NVMeoF 4KB read IOs over ConnectX-5EX across Spectrum switch. TX-depth = 32. The patch was applied in the nvme driver on both the target and initiator. Four controllers are accessed from each core. In the current test case we have exposed sixteen NVMe namespaces using four different subsystems (four namespaces per subsystem) from one NVM port. Each controller allocated X queues (RDMA QPs) and attached to Y CQs. Before this series we had X == Y, i.e for four controllers we've created total of 4X QPs and 4X CQs. In the shared case, we've created 4X QPs and only X CQs which means that we have four controllers that share a completion queue per core. Until fourteen cores there is no significant change in performance and the number of interrupts per second is less than a million in the current case. ================================================== |Cores|Current KIOPs |Shared KIOPs |improvement| |-----|---------------|--------------|-----------| |14 |2332 |2723 |16.7% | |-----|---------------|--------------|-----------| |20 |2086 |2712 |30% | |-----|---------------|--------------|-----------| |28 |1971 |2669 |35.4% | |================================================= |Cores|Current avg lat|Shared avg lat|improvement| |-----|---------------|--------------|-----------| |14 |767us |657us |14.3% | |-----|---------------|--------------|-----------| |20 |1225us |943us |23% | |-----|---------------|--------------|-----------| |28 |1816us |1341us |26.1% | ======================================================== |Cores|Current interrupts|Shared interrupts|improvement| |-----|------------------|-----------------|-----------| |14 |1.6M/sec |0.4M/sec |72% | |-----|------------------|-----------------|-----------| |20 |2.8M/sec |0.6M/sec |72.4% | |-----|------------------|-----------------|-----------| |28 |2.9M/sec |0.8M/sec |63.4% | ==================================================================== |Cores|Current 99.99th PCTL lat|Shared 99.99th PCTL lat|improvement| |-----|------------------------|-----------------------|-----------| |14 |67ms |6ms |90.9% | |-----|------------------------|-----------------------|-----------| |20 |5ms |6ms |-10% | |-----|------------------------|-----------------------|-----------| |28 |8.7ms |6ms |25.9% | |=================================================================== Performance improvement with sixteen disks (sixteen CQs per core) is comparable. Link: https://lore.kernel.org/r/1590568495-101621-3-git-send-email-yaminf@mellanox.com Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-27 11:34:53 +03:00
RDMA/core: Provide RDMA DIM support for ULPs Added the interface in the infiniband driver that applies the rdma_dim adaptive moderation. There is now a special function for allocating an ib_cq that uses rdma_dim. Performance improvement (ConnectX-5 100GbE, x86) running FIO benchmark over NVMf between two equal end-hosts with 56 cores across a Mellanox switch using null_blk device: READS without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.8GiB/s | 7.7M | 1401 usec | 2442 usec 4k | 7.0GiB/s | 1.8M | 4817 usec | 6587 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES without DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.6GiB/s | 7.5M | 1434 usec | 2474 usec 4k | 6.3GiB/s | 1.6M | 938 usec | 1221 usec 64k | 10.7GiB/s| 175k | 8979 usec | 12780 usec IO READS with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 4GiB/s | 8.2M | 816 usec | 889 usec 4k | 10.1GiB/s| 2.65M| 3359 usec | 5080 usec 64k | 10.7GiB/s| 175k | 9896 usec | 10028 usec IO WRITES with DIM: blk size | BW | IOPS | 99th percentile latency | 99.99th latency 512B | 3.9GiB/s | 8.1M | 799 usec | 922 usec 4k | 9.6GiB/s | 2.5M | 717 usec | 1004 usec 64k | 10.7GiB/s| 176k | 8586 usec | 12256 usec The rdma_dim algorithm was designed to measure the effectiveness of moderation on the flow in a general way and thus should be appropriate for all RDMA storage protocols. rdma_dim is configured to be the default option based on performance improvement seen after extensive tests. Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-07-08 13:59:03 +03:00
RDMA/core: Trace points for diagnosing completion queue issues Sample trace events: kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE <idle>-0 [002] 120.056292: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067503: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067657: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1 ... systemd-1 [002] 122.392653: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3 Several features to note in this output: - The WCE count and context type are reported at allocation time - The CPU and kworker for each CQ is evident - The CQ's restracker ID is tagged on each trace event - CQ poll scheduling latency is measured - Details about how often single completions occur versus multiple completions are evident - The cost of the ULP's completion handler is recorded Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-12-18 15:18:15 -05:00
RDMA/core: Trace points for diagnosing completion queue issues Sample trace events: kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE <idle>-0 [002] 120.056292: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067503: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067657: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1 ... systemd-1 [002] 122.392653: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3 Several features to note in this output: - The WCE count and context type are reported at allocation time - The CPU and kworker for each CQ is evident - The CQ's restracker ID is tagged on each trace event - CQ poll scheduling latency is measured - Details about how often single completions occur versus multiple completions are evident - The cost of the ULP's completion handler is recorded Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-12-18 15:18:15 -05:00
RDMA/core: Introduce shared CQ pool API Allow a ULP to ask the core to provide a completion queue based on a least-used search on a per-device CQ pools. The device CQ pools grow in a lazy fashion when more CQs are requested. This feature reduces the amount of interrupts when using many QPs. Using shared CQs allows for more effcient completion handling. It also reduces the amount of overhead needed for CQ contexts. Test setup: Intel(R) Xeon(R) Platinum 8176M CPU @ 2.10GHz servers. Running NVMeoF 4KB read IOs over ConnectX-5EX across Spectrum switch. TX-depth = 32. The patch was applied in the nvme driver on both the target and initiator. Four controllers are accessed from each core. In the current test case we have exposed sixteen NVMe namespaces using four different subsystems (four namespaces per subsystem) from one NVM port. Each controller allocated X queues (RDMA QPs) and attached to Y CQs. Before this series we had X == Y, i.e for four controllers we've created total of 4X QPs and 4X CQs. In the shared case, we've created 4X QPs and only X CQs which means that we have four controllers that share a completion queue per core. Until fourteen cores there is no significant change in performance and the number of interrupts per second is less than a million in the current case. ================================================== |Cores|Current KIOPs |Shared KIOPs |improvement| |-----|---------------|--------------|-----------| |14 |2332 |2723 |16.7% | |-----|---------------|--------------|-----------| |20 |2086 |2712 |30% | |-----|---------------|--------------|-----------| |28 |1971 |2669 |35.4% | |================================================= |Cores|Current avg lat|Shared avg lat|improvement| |-----|---------------|--------------|-----------| |14 |767us |657us |14.3% | |-----|---------------|--------------|-----------| |20 |1225us |943us |23% | |-----|---------------|--------------|-----------| |28 |1816us |1341us |26.1% | ======================================================== |Cores|Current interrupts|Shared interrupts|improvement| |-----|------------------|-----------------|-----------| |14 |1.6M/sec |0.4M/sec |72% | |-----|------------------|-----------------|-----------| |20 |2.8M/sec |0.6M/sec |72.4% | |-----|------------------|-----------------|-----------| |28 |2.9M/sec |0.8M/sec |63.4% | ==================================================================== |Cores|Current 99.99th PCTL lat|Shared 99.99th PCTL lat|improvement| |-----|------------------------|-----------------------|-----------| |14 |67ms |6ms |90.9% | |-----|------------------------|-----------------------|-----------| |20 |5ms |6ms |-10% | |-----|------------------------|-----------------------|-----------| |28 |8.7ms |6ms |25.9% | |=================================================================== Performance improvement with sixteen disks (sixteen CQs per core) is comparable. Link: https://lore.kernel.org/r/1590568495-101621-3-git-send-email-yaminf@mellanox.com Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-27 11:34:53 +03:00
RDMA/core: Trace points for diagnosing completion queue issues Sample trace events: kworker/u29:0-300 [007] 120.042217: cq_alloc: cq.id=4 nr_cqe=161 comp_vector=2 poll_ctx=WORKQUEUE <idle>-0 [002] 120.056292: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.056402: cq_process: cq.id=4 wake-up took 109 [us] from interrupt kworker/2:1H-482 [002] 120.056407: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067503: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067537: cq_process: cq.id=4 wake-up took 34 [us] from interrupt kworker/2:1H-482 [002] 120.067541: cq_poll: cq.id=4 requested 16, returned 1 <idle>-0 [002] 120.067657: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 120.067672: cq_process: cq.id=4 wake-up took 15 [us] from interrupt kworker/2:1H-482 [002] 120.067674: cq_poll: cq.id=4 requested 16, returned 1 ... systemd-1 [002] 122.392653: cq_schedule: cq.id=4 kworker/2:1H-482 [002] 122.392688: cq_process: cq.id=4 wake-up took 35 [us] from interrupt kworker/2:1H-482 [002] 122.392693: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392836: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.392970: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393083: cq_poll: cq.id=4 requested 16, returned 16 kworker/2:1H-482 [002] 122.393195: cq_poll: cq.id=4 requested 16, returned 3 Several features to note in this output: - The WCE count and context type are reported at allocation time - The CPU and kworker for each CQ is evident - The CQ's restracker ID is tagged on each trace event - CQ poll scheduling latency is measured - Details about how often single completions occur versus multiple completions are evident - The cost of the ULP's completion handler is recorded Link: https://lore.kernel.org/r/20191218201815.30584.3481.stgit@manet.1015granger.net Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Reviewed-by: Parav Pandit <parav@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-12-18 15:18:15 -05:00
RDMA/core: Introduce shared CQ pool API Allow a ULP to ask the core to provide a completion queue based on a least-used search on a per-device CQ pools. The device CQ pools grow in a lazy fashion when more CQs are requested. This feature reduces the amount of interrupts when using many QPs. Using shared CQs allows for more effcient completion handling. It also reduces the amount of overhead needed for CQ contexts. Test setup: Intel(R) Xeon(R) Platinum 8176M CPU @ 2.10GHz servers. Running NVMeoF 4KB read IOs over ConnectX-5EX across Spectrum switch. TX-depth = 32. The patch was applied in the nvme driver on both the target and initiator. Four controllers are accessed from each core. In the current test case we have exposed sixteen NVMe namespaces using four different subsystems (four namespaces per subsystem) from one NVM port. Each controller allocated X queues (RDMA QPs) and attached to Y CQs. Before this series we had X == Y, i.e for four controllers we've created total of 4X QPs and 4X CQs. In the shared case, we've created 4X QPs and only X CQs which means that we have four controllers that share a completion queue per core. Until fourteen cores there is no significant change in performance and the number of interrupts per second is less than a million in the current case. ================================================== |Cores|Current KIOPs |Shared KIOPs |improvement| |-----|---------------|--------------|-----------| |14 |2332 |2723 |16.7% | |-----|---------------|--------------|-----------| |20 |2086 |2712 |30% | |-----|---------------|--------------|-----------| |28 |1971 |2669 |35.4% | |================================================= |Cores|Current avg lat|Shared avg lat|improvement| |-----|---------------|--------------|-----------| |14 |767us |657us |14.3% | |-----|---------------|--------------|-----------| |20 |1225us |943us |23% | |-----|---------------|--------------|-----------| |28 |1816us |1341us |26.1% | ======================================================== |Cores|Current interrupts|Shared interrupts|improvement| |-----|------------------|-----------------|-----------| |14 |1.6M/sec |0.4M/sec |72% | |-----|------------------|-----------------|-----------| |20 |2.8M/sec |0.6M/sec |72.4% | |-----|------------------|-----------------|-----------| |28 |2.9M/sec |0.8M/sec |63.4% | ==================================================================== |Cores|Current 99.99th PCTL lat|Shared 99.99th PCTL lat|improvement| |-----|------------------------|-----------------------|-----------| |14 |67ms |6ms |90.9% | |-----|------------------------|-----------------------|-----------| |20 |5ms |6ms |-10% | |-----|------------------------|-----------------------|-----------| |28 |8.7ms |6ms |25.9% | |=================================================================== Performance improvement with sixteen disks (sixteen CQs per core) is comparable. Link: https://lore.kernel.org/r/1590568495-101621-3-git-send-email-yaminf@mellanox.com Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-27 11:34:53 +03:00
RDMA/core: Clean up cq pool mechanism The CQ pool mechanism had two problems: 1. The CQ pool lists were uninitialized in the device registration error flow. As a result, all the list pointers remained NULL. This caused the kernel to crash (in procedure ib_cq_pool_destroy) when that error flow was taken (and unregister called). The stack trace snippet: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0×0000) ? not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI . . . RIP: 0010:ib_cq_pool_destroy+0x1b/0×70 [ib_core] . . . Call Trace: disable_device+0x9f/0×130 [ib_core] __ib_unregister_device+0x35/0×90 [ib_core] ib_register_device+0x529/0×610 [ib_core] __mlx5_ib_add+0x3a/0×70 [mlx5_ib] mlx5_add_device+0x87/0×1c0 [mlx5_core] mlx5_register_interface+0x74/0xc0 [mlx5_core] do_one_initcall+0x4b/0×1f4 do_init_module+0x5a/0×223 load_module+0x1938/0×1d40 2. At device unregister, when cleaning up the cq pool, the cq's in the pool lists were freed, but the cq entries were left in the list. The fix for the first issue is to initialize the cq pool lists when the ib_device structure is allocated for a new device (in procedure _ib_alloc_device). The fix for the second problem is to delete cq entries from the pool lists when cleaning up the cq pool. In addition, procedure ib_cq_pool_destroy() is renamed to the more appropriate name ib_cq_pool_cleanup(). Fixes: 4aa1615268a8 ("RDMA/core: Fix ordering of CQ pool destruction") Link: https://lore.kernel.org/r/20201208073545.9723-2-leon@kernel.org Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2020-12-08 09:35:43 +02:00
RDMA/core: Introduce shared CQ pool API Allow a ULP to ask the core to provide a completion queue based on a least-used search on a per-device CQ pools. The device CQ pools grow in a lazy fashion when more CQs are requested. This feature reduces the amount of interrupts when using many QPs. Using shared CQs allows for more effcient completion handling. It also reduces the amount of overhead needed for CQ contexts. Test setup: Intel(R) Xeon(R) Platinum 8176M CPU @ 2.10GHz servers. Running NVMeoF 4KB read IOs over ConnectX-5EX across Spectrum switch. TX-depth = 32. The patch was applied in the nvme driver on both the target and initiator. Four controllers are accessed from each core. In the current test case we have exposed sixteen NVMe namespaces using four different subsystems (four namespaces per subsystem) from one NVM port. Each controller allocated X queues (RDMA QPs) and attached to Y CQs. Before this series we had X == Y, i.e for four controllers we've created total of 4X QPs and 4X CQs. In the shared case, we've created 4X QPs and only X CQs which means that we have four controllers that share a completion queue per core. Until fourteen cores there is no significant change in performance and the number of interrupts per second is less than a million in the current case. ================================================== |Cores|Current KIOPs |Shared KIOPs |improvement| |-----|---------------|--------------|-----------| |14 |2332 |2723 |16.7% | |-----|---------------|--------------|-----------| |20 |2086 |2712 |30% | |-----|---------------|--------------|-----------| |28 |1971 |2669 |35.4% | |================================================= |Cores|Current avg lat|Shared avg lat|improvement| |-----|---------------|--------------|-----------| |14 |767us |657us |14.3% | |-----|---------------|--------------|-----------| |20 |1225us |943us |23% | |-----|---------------|--------------|-----------| |28 |1816us |1341us |26.1% | ======================================================== |Cores|Current interrupts|Shared interrupts|improvement| |-----|------------------|-----------------|-----------| |14 |1.6M/sec |0.4M/sec |72% | |-----|------------------|-----------------|-----------| |20 |2.8M/sec |0.6M/sec |72.4% | |-----|------------------|-----------------|-----------| |28 |2.9M/sec |0.8M/sec |63.4% | ==================================================================== |Cores|Current 99.99th PCTL lat|Shared 99.99th PCTL lat|improvement| |-----|------------------------|-----------------------|-----------| |14 |67ms |6ms |90.9% | |-----|------------------------|-----------------------|-----------| |20 |5ms |6ms |-10% | |-----|------------------------|-----------------------|-----------| |28 |8.7ms |6ms |25.9% | |=================================================================== Performance improvement with sixteen disks (sixteen CQs per core) is comparable. Link: https://lore.kernel.org/r/1590568495-101621-3-git-send-email-yaminf@mellanox.com Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-27 11:34:53 +03:00
RDMA/core: Clean up cq pool mechanism The CQ pool mechanism had two problems: 1. The CQ pool lists were uninitialized in the device registration error flow. As a result, all the list pointers remained NULL. This caused the kernel to crash (in procedure ib_cq_pool_destroy) when that error flow was taken (and unregister called). The stack trace snippet: BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor read access in kernel mode #PF: error_code(0×0000) ? not-present page PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI . . . RIP: 0010:ib_cq_pool_destroy+0x1b/0×70 [ib_core] . . . Call Trace: disable_device+0x9f/0×130 [ib_core] __ib_unregister_device+0x35/0×90 [ib_core] ib_register_device+0x529/0×610 [ib_core] __mlx5_ib_add+0x3a/0×70 [mlx5_ib] mlx5_add_device+0x87/0×1c0 [mlx5_core] mlx5_register_interface+0x74/0xc0 [mlx5_core] do_one_initcall+0x4b/0×1f4 do_init_module+0x5a/0×223 load_module+0x1938/0×1d40 2. At device unregister, when cleaning up the cq pool, the cq's in the pool lists were freed, but the cq entries were left in the list. The fix for the first issue is to initialize the cq pool lists when the ib_device structure is allocated for a new device (in procedure _ib_alloc_device). The fix for the second problem is to delete cq entries from the pool lists when cleaning up the cq pool. In addition, procedure ib_cq_pool_destroy() is renamed to the more appropriate name ib_cq_pool_cleanup(). Fixes: 4aa1615268a8 ("RDMA/core: Fix ordering of CQ pool destruction") Link: https://lore.kernel.org/r/20201208073545.9723-2-leon@kernel.org Suggested-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il> Signed-off-by: Leon Romanovsky <leonro@nvidia.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2020-12-08 09:35:43 +02:00
RDMA/core: Introduce shared CQ pool API Allow a ULP to ask the core to provide a completion queue based on a least-used search on a per-device CQ pools. The device CQ pools grow in a lazy fashion when more CQs are requested. This feature reduces the amount of interrupts when using many QPs. Using shared CQs allows for more effcient completion handling. It also reduces the amount of overhead needed for CQ contexts. Test setup: Intel(R) Xeon(R) Platinum 8176M CPU @ 2.10GHz servers. Running NVMeoF 4KB read IOs over ConnectX-5EX across Spectrum switch. TX-depth = 32. The patch was applied in the nvme driver on both the target and initiator. Four controllers are accessed from each core. In the current test case we have exposed sixteen NVMe namespaces using four different subsystems (four namespaces per subsystem) from one NVM port. Each controller allocated X queues (RDMA QPs) and attached to Y CQs. Before this series we had X == Y, i.e for four controllers we've created total of 4X QPs and 4X CQs. In the shared case, we've created 4X QPs and only X CQs which means that we have four controllers that share a completion queue per core. Until fourteen cores there is no significant change in performance and the number of interrupts per second is less than a million in the current case. ================================================== |Cores|Current KIOPs |Shared KIOPs |improvement| |-----|---------------|--------------|-----------| |14 |2332 |2723 |16.7% | |-----|---------------|--------------|-----------| |20 |2086 |2712 |30% | |-----|---------------|--------------|-----------| |28 |1971 |2669 |35.4% | |================================================= |Cores|Current avg lat|Shared avg lat|improvement| |-----|---------------|--------------|-----------| |14 |767us |657us |14.3% | |-----|---------------|--------------|-----------| |20 |1225us |943us |23% | |-----|---------------|--------------|-----------| |28 |1816us |1341us |26.1% | ======================================================== |Cores|Current interrupts|Shared interrupts|improvement| |-----|------------------|-----------------|-----------| |14 |1.6M/sec |0.4M/sec |72% | |-----|------------------|-----------------|-----------| |20 |2.8M/sec |0.6M/sec |72.4% | |-----|------------------|-----------------|-----------| |28 |2.9M/sec |0.8M/sec |63.4% | ==================================================================== |Cores|Current 99.99th PCTL lat|Shared 99.99th PCTL lat|improvement| |-----|------------------------|-----------------------|-----------| |14 |67ms |6ms |90.9% | |-----|------------------------|-----------------------|-----------| |20 |5ms |6ms |-10% | |-----|------------------------|-----------------------|-----------| |28 |8.7ms |6ms |25.9% | |=================================================================== Performance improvement with sixteen disks (sixteen CQs per core) is comparable. Link: https://lore.kernel.org/r/1590568495-101621-3-git-send-email-yaminf@mellanox.com Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-27 11:34:53 +03:00
RDMA/core: Introduce shared CQ pool API Allow a ULP to ask the core to provide a completion queue based on a least-used search on a per-device CQ pools. The device CQ pools grow in a lazy fashion when more CQs are requested. This feature reduces the amount of interrupts when using many QPs. Using shared CQs allows for more effcient completion handling. It also reduces the amount of overhead needed for CQ contexts. Test setup: Intel(R) Xeon(R) Platinum 8176M CPU @ 2.10GHz servers. Running NVMeoF 4KB read IOs over ConnectX-5EX across Spectrum switch. TX-depth = 32. The patch was applied in the nvme driver on both the target and initiator. Four controllers are accessed from each core. In the current test case we have exposed sixteen NVMe namespaces using four different subsystems (four namespaces per subsystem) from one NVM port. Each controller allocated X queues (RDMA QPs) and attached to Y CQs. Before this series we had X == Y, i.e for four controllers we've created total of 4X QPs and 4X CQs. In the shared case, we've created 4X QPs and only X CQs which means that we have four controllers that share a completion queue per core. Until fourteen cores there is no significant change in performance and the number of interrupts per second is less than a million in the current case. ================================================== |Cores|Current KIOPs |Shared KIOPs |improvement| |-----|---------------|--------------|-----------| |14 |2332 |2723 |16.7% | |-----|---------------|--------------|-----------| |20 |2086 |2712 |30% | |-----|---------------|--------------|-----------| |28 |1971 |2669 |35.4% | |================================================= |Cores|Current avg lat|Shared avg lat|improvement| |-----|---------------|--------------|-----------| |14 |767us |657us |14.3% | |-----|---------------|--------------|-----------| |20 |1225us |943us |23% | |-----|---------------|--------------|-----------| |28 |1816us |1341us |26.1% | ======================================================== |Cores|Current interrupts|Shared interrupts|improvement| |-----|------------------|-----------------|-----------| |14 |1.6M/sec |0.4M/sec |72% | |-----|------------------|-----------------|-----------| |20 |2.8M/sec |0.6M/sec |72.4% | |-----|------------------|-----------------|-----------| |28 |2.9M/sec |0.8M/sec |63.4% | ==================================================================== |Cores|Current 99.99th PCTL lat|Shared 99.99th PCTL lat|improvement| |-----|------------------------|-----------------------|-----------| |14 |67ms |6ms |90.9% | |-----|------------------------|-----------------------|-----------| |20 |5ms |6ms |-10% | |-----|------------------------|-----------------------|-----------| |28 |8.7ms |6ms |25.9% | |=================================================================== Performance improvement with sixteen disks (sixteen CQs per core) is comparable. Link: https://lore.kernel.org/r/1590568495-101621-3-git-send-email-yaminf@mellanox.com Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-27 11:34:53 +03:00
RDMA/core: Introduce shared CQ pool API Allow a ULP to ask the core to provide a completion queue based on a least-used search on a per-device CQ pools. The device CQ pools grow in a lazy fashion when more CQs are requested. This feature reduces the amount of interrupts when using many QPs. Using shared CQs allows for more effcient completion handling. It also reduces the amount of overhead needed for CQ contexts. Test setup: Intel(R) Xeon(R) Platinum 8176M CPU @ 2.10GHz servers. Running NVMeoF 4KB read IOs over ConnectX-5EX across Spectrum switch. TX-depth = 32. The patch was applied in the nvme driver on both the target and initiator. Four controllers are accessed from each core. In the current test case we have exposed sixteen NVMe namespaces using four different subsystems (four namespaces per subsystem) from one NVM port. Each controller allocated X queues (RDMA QPs) and attached to Y CQs. Before this series we had X == Y, i.e for four controllers we've created total of 4X QPs and 4X CQs. In the shared case, we've created 4X QPs and only X CQs which means that we have four controllers that share a completion queue per core. Until fourteen cores there is no significant change in performance and the number of interrupts per second is less than a million in the current case. ================================================== |Cores|Current KIOPs |Shared KIOPs |improvement| |-----|---------------|--------------|-----------| |14 |2332 |2723 |16.7% | |-----|---------------|--------------|-----------| |20 |2086 |2712 |30% | |-----|---------------|--------------|-----------| |28 |1971 |2669 |35.4% | |================================================= |Cores|Current avg lat|Shared avg lat|improvement| |-----|---------------|--------------|-----------| |14 |767us |657us |14.3% | |-----|---------------|--------------|-----------| |20 |1225us |943us |23% | |-----|---------------|--------------|-----------| |28 |1816us |1341us |26.1% | ======================================================== |Cores|Current interrupts|Shared interrupts|improvement| |-----|------------------|-----------------|-----------| |14 |1.6M/sec |0.4M/sec |72% | |-----|------------------|-----------------|-----------| |20 |2.8M/sec |0.6M/sec |72.4% | |-----|------------------|-----------------|-----------| |28 |2.9M/sec |0.8M/sec |63.4% | ==================================================================== |Cores|Current 99.99th PCTL lat|Shared 99.99th PCTL lat|improvement| |-----|------------------------|-----------------------|-----------| |14 |67ms |6ms |90.9% | |-----|------------------------|-----------------------|-----------| |20 |5ms |6ms |-10% | |-----|------------------------|-----------------------|-----------| |28 |8.7ms |6ms |25.9% | |=================================================================== Performance improvement with sixteen disks (sixteen CQs per core) is comparable. Link: https://lore.kernel.org/r/1590568495-101621-3-git-send-email-yaminf@mellanox.com Signed-off-by: Yamin Friedman <yaminf@mellanox.com> Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com> Reviewed-by: Max Gurtovoy <maxg@mellanox.com> Reviewed-by: Leon Romanovsky <leonro@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2020-05-27 11:34:53 +03:00