linux/include
Jianxin Xiong d9b13c2030 IB/rdmavt, hfi1: Fix NFSoRDMA failure with FRMR enabled
Hanging has been observed while writing a file over NFSoRDMA. Dmesg on
the server contains messages like these:

[  931.992501] svcrdma: Error -22 posting RDMA_READ
[  952.076879] svcrdma: Error -22 posting RDMA_READ
[  982.154127] svcrdma: Error -22 posting RDMA_READ
[ 1012.235884] svcrdma: Error -22 posting RDMA_READ
[ 1042.319194] svcrdma: Error -22 posting RDMA_READ

Here is why:

With the base memory management extension enabled, FRMR is used instead
of FMR. The xprtrdma server issues each RDMA read request as the following
bundle:

(1)IB_WR_REG_MR, signaled;
(2)IB_WR_RDMA_READ, signaled;
(3)IB_WR_LOCAL_INV, signaled & fencing.

These requests are signaled. In order to generate completion, the fast
register work request is processed by the hfi1 send engine after being
posted to the work queue, and the corresponding lkey is not valid until
the request is processed. However, the rdmavt driver validates lkey when
the RDMA read request is posted and thus it fails immediately with error
-EINVAL (-22).

This patch changes the work flow of local operations (fast register and
local invalidate) so that fast register work requests are always
processed immediately to ensure that the corresponding lkey is valid
when subsequent work requests are posted. Local invalidate requests are
processed immediately if fencing is not required and no previous local
invalidate request is pending.

To allow completion generation for signaled local operations that have
been processed before posting to the work queue, an internal send flag
RVT_SEND_COMPLETION_ONLY is added. The hfi1 send engine checks this flag
and only generates completion for such requests.

Reviewed-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Jianxin Xiong <jianxin.xiong@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
2016-08-02 16:00:58 -04:00
..
acpi Revert "ACPI 2.0 / AML: Improve module level execution by moving the If/Else/While execution to per-table basis" 2016-07-11 16:21:08 +02:00
asm-generic vmlinux.lds: account for destructor sections 2016-07-15 14:54:27 +09:00
clocksource
crypto Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-05-19 09:21:36 -07:00
drm Merge branch 'drm-vmwgfx-fixes' of git://people.freedesktop.org/~syeh/repos_linux into drm-fixes 2016-07-15 13:51:55 +10:00
dt-bindings Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2016-05-26 09:23:43 -07:00
keys
kvm arm64: KVM: fix build with CONFIG_ARM_PMU disabled 2016-06-27 12:55:51 +02:00
linux Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2016-07-23 15:44:31 +09:00
math-emu
media Update my main e-mails at the Kernel tree 2016-06-15 15:35:37 -10:00
memory
misc
net net: switchdev: change ageing_time type to clock_t 2016-07-19 16:49:20 -07:00
pcmcia
ras
rdma IB/rdmavt, hfi1: Fix NFSoRDMA failure with FRMR enabled 2016-08-02 16:00:58 -04:00
rxrpc
scsi
soc ARC updates for 4.7-rc1 2016-05-19 09:46:18 -07:00
sound ASoC: Updates for v4.7 2016-05-16 14:59:00 +02:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2016-05-28 12:04:17 -07:00
trace - move kvm_stat tool from QEMU repo into tools/kvm/kvm_stat 2016-05-27 13:41:54 -07:00
uapi Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input 2016-07-16 07:04:12 +09:00
video imx-drm probing fix 2016-05-25 12:36:20 +10:00
xen
Kbuild