summaryrefslogtreecommitdiffstats
path: root/Documentation/ABI/stable/sysfs-driver-ib_srp
AgeCommit message (Collapse)AuthorFilesLines
2014-11-12IB/srp: Add multichannel supportBart Van Assche1-6/+19
Improve performance by using multiple RDMA/RC channels per SCSI host for communication with an SRP target. About the implementation: - Introduce a loop over all channels in the code that uses target->ch. - Set the SRP_MULTICHAN_MULTI flag during login for the creation of the second and subsequent channels. - RDMA completion vectors are chosen such that RDMA completion interrupts are handled by the CPU socket that submitted the I/O request. As one can see in this patch it has been assumed if a system contains n CPU sockets and m RDMA completion vectors have been assigned to an RDMA HCA that IRQ affinity has been configured such that completion vectors [i*m/n..(i+1)*m/n) are bound to CPU socket i with 0 <= i < n. - Modify srp_free_ch_ib() and srp_free_req_data() such that it becomes safe to invoke these functions after the corresponding allocation function failed. - Add a ch_count sysfs attribute per target port. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Sagi Grimberg <sagig@mellanox.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2013-11-08IB/srp: Make queue size configurableBart Van Assche1-0/+4
Certain storage configurations, e.g. a sufficiently large array of hard disks in a RAID configuration, need a queue depth above 64 to achieve optimal performance. Hence make the queue depth configurable. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Tested-by: Jack Wang <xjtuwjp@gmail.com> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Export sgid to sysfsBart Van Assche1-0/+7
On an initiator system with multiple IB ports it is not yet possible to figure out what the originating port of an SRP connection is. Hence make the source GID available in sysfs. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-11-08IB/srp: Make transport layer retry count configurableVu Pham1-0/+2
Allow the InfiniBand RC retry count to be configured by the user as an option in the target login string. Reducing this retry count allows to reduce the path failover time. Signed-off-by: Vu Pham <vu@mellanox.com> [ bvanassche: Rewrote patch description / changed default retry count ] Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2013-07-01IB/srp: Make HCA completion vector configurableBart Van Assche1-0/+7
Several InfiniBand HCAs allow configuring the completion vector per CQ. This allows spreading the workload created by IB completion interrupts over multiple MSI-X vectors and hence over multiple CPU cores. In other words, configuring the completion vector properly not only allows reducing latency on an initiator connected to multiple SRP targets but also allows improving throughput. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>
2012-11-30IB/srp: Document sysfs attributesBart Van Assche1-0/+156
Document the sysfs attributes of the SRP initiator (ib_srp) according to the rules specified in Documentation/ABI/README. Signed-off-by: Bart Van Assche <bvanassche@acm.org> Acked-by: David Dillow <dillowda@ornl.gov> Signed-off-by: Roland Dreier <roland@purestorage.com>