android_kernel_motorola_sm6225/drivers/infiniband
CQ Tang 49c0e2414b IB/qib: Change SDMA progression mode depending on single- or multi-rail
Improve performance by changing the behavour of the driver when all
SDMA descriptors are in use, and the processes adding new descriptors
are single- or multi-rail.

For single-rail processes, the driver will block the call and finish
posting all SDMA descriptors onto the hardware queue before returning
back to PSM.  Repeated kernel calls are slower than blocking.

For multi-rail processes, the driver will return to PSM as quick as
possible so PSM can feed packets to other rail.  If all hardware
queues are full, PSM will buffer the remaining SDMA descriptors until
notified by interrupt that space is available.

This patch builds a red-black tree to track the number rails opened by
a particular PID. If the number is more than one, it is a multi-rail
PSM process, otherwise, it is a single-rail process.

Reviewed-by: Dean Luick <dean.luick@intel.com>
Reviewed-by: John A Gregor <john.a.gregor@intel.com>
Reviewed-by: Mitko Haralanov <mitko.haralanov@intel.com>
Signed-off-by: CQ Tang <cq.tang@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
2014-03-20 10:19:12 -07:00
..
core Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
hw IB/qib: Change SDMA progression mode depending on single- or multi-rail 2014-03-20 10:19:12 -07:00
ulp Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2014-02-15 16:18:47 -08:00
Kconfig Merge branch 'ip-roce' into for-next 2014-01-22 23:24:21 -08:00
Makefile IB/usnic: Add Cisco VIC low-level hardware driver 2014-01-14 00:44:28 -08:00