]> git.karo-electronics.de Git - linux-beck.git/commit
IB/qib: Use RCU for qpn lookup
authorMike Marciniszyn <mike.marciniszyn@qlogic.com>
Fri, 23 Sep 2011 17:16:44 +0000 (13:16 -0400)
committerRoland Dreier <roland@purestorage.com>
Fri, 21 Oct 2011 16:38:54 +0000 (09:38 -0700)
commitaf061a644a0e4d4778fe6cd2246479c1962e153b
tree01ed5c508274adc6e46f99d4091fffe70632711f
parent9e1c0e43257b6df1ef012dd37c3f0f93b1ee47af
IB/qib: Use RCU for qpn lookup

The heavy weight spinlock in qib_lookup_qpn() is replaced with RCU.
The hash list itself is now accessed via jhash functions instead of mod.

The changes should benefit multiple receive contexts in different
processors by not contending for the lock just to read the hash
structures.

The patch also adds a lookaside_qp (pointer) and a lookaside_qpn in
the context.  The interrupt handler will test the current packet's qpn
against lookaside_qpn if the lookaside_qp pointer is non-NULL.  The
pointer is NULL'ed when the interrupt handler exits.

Signed-off-by: Mike Marciniszyn <mike.marciniszyn@qlogic.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
drivers/infiniband/hw/qib/qib.h
drivers/infiniband/hw/qib/qib_driver.c
drivers/infiniband/hw/qib/qib_qp.c
drivers/infiniband/hw/qib/qib_verbs.c
drivers/infiniband/hw/qib/qib_verbs.h