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authorBart Van Assche <bvanassche@acm.org>2013-06-28 14:57:42 +0200
committerRoland Dreier <roland@purestorage.com>2013-07-01 19:40:55 +0200
commit4b5e5f41c8e114bb856347134657eb9e1cccc822 (patch)
treecdca03a8d34e6c190b021a54c98925eaf1330c7c /Documentation
parentIB/srp: Maintain a single connection per I_T nexus (diff)
downloadlinux-4b5e5f41c8e114bb856347134657eb9e1cccc822.tar.xz
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IB/srp: Make HCA completion vector configurable
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>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/ABI/stable/sysfs-driver-ib_srp7
1 files changed, 7 insertions, 0 deletions
diff --git a/Documentation/ABI/stable/sysfs-driver-ib_srp b/Documentation/ABI/stable/sysfs-driver-ib_srp
index 481aae95c7d1..5c53d28f775c 100644
--- a/Documentation/ABI/stable/sysfs-driver-ib_srp
+++ b/Documentation/ABI/stable/sysfs-driver-ib_srp
@@ -54,6 +54,13 @@ Description: Interface for making ib_srp connect to a new target.
ib_srp. Specifying a value that exceeds cmd_sg_entries is
only safe with partial memory descriptor list support enabled
(allow_ext_sg=1).
+ * comp_vector, a number in the range 0..n-1 specifying the
+ MSI-X completion vector. Some HCA's allocate multiple (n)
+ MSI-X vectors per HCA port. If the IRQ affinity masks of
+ these interrupts have been configured such that each MSI-X
+ interrupt is handled by a different CPU then the comp_vector
+ parameter can be used to spread the SRP completion workload
+ over multiple CPU's.
What: /sys/class/infiniband_srp/srp-<hca>-<port_number>/ibdev
Date: January 2, 2006