linux-toradex.git/include/linux/sunrpc/svc_rdma.h, branch v5.3.2

sunrpc: remove unused xpo_prep_reply_hdr callback

2018-12-28T02:01:41+00:00

xpo_prep_reply_hdr are not used now.

It was defined for tcp transport only, however it cannot be
called indirectly, so let's move it to its caller and
remove unused callback.

Signed-off-by: Vasily Averin 
Signed-off-by: J. Bruce Fields

svcrdma: Optimize the logic that selects the R_key to invalidate

2018-11-28T23:36:03+00:00

o Select the R_key to invalidate while the CPU cache still contains
  the received RPC Call transport header, rather than waiting until
  we're about to send the RPC Reply.

o Choose Send With Invalidate if there is exactly one distinct R_key
  in the received transport header. If there's more than one, the
  client will have to perform local invalidation after it has
  already waited for remote invalidation.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

svcrdma: Increase the default connection credit limit

2018-10-29T20:58:04+00:00

Reduce queuing on clients by allowing more credits by default.

64 is the default NFSv4.1 slot table size on Linux clients. This
size prevents the credit limit from putting RPC requests to sleep
again after they have already slept waiting for a session slot.

Signed-off-by: Chuck Lever 
Reviewed-by: Sagi Grimberg 
Signed-off-by: J. Bruce Fields

svcrdma: Remove unused svc_rdma_op_ctxt

2018-05-11T19:48:57+00:00

Clean up: Eliminate a structure that is no longer used.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

svcrdma: Persistently allocate and DMA-map Send buffers

2018-05-11T19:48:57+00:00

While sending each RPC Reply, svc_rdma_sendto allocates and DMA-
maps a separate buffer where the RPC/RDMA transport header is
constructed. The buffer is unmapped and released in the Send
completion handler. This is significant per-RPC overhead,
especially for small RPCs.

Instead, allocate and DMA-map a buffer, and cache it in each
svc_rdma_send_ctxt. This buffer and its mapping can be re-used
for each RPC, saving the cost of memory allocation and DMA
mapping.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

svcrdma: Remove post_send_wr

2018-05-11T19:48:57+00:00

Clean up: Now that the send_wr is part of the svc_rdma_send_ctxt,
svc_rdma_post_send_wr is nearly empty.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

svcrdma: Don't overrun the SGE array in svc_rdma_send_ctxt

2018-05-11T19:48:57+00:00

Receive buffers are always the same size, but each Send WR has a
variable number of SGEs, based on the contents of the xdr_buf being
sent.

While assembling a Send WR, keep track of the number of SGEs so that
we don't exceed the device's maximum, or walk off the end of the
Send SGE array.

For now the Send path just fails if it exceeds the maximum.

The current logic in svc_rdma_accept bases the maximum number of
Send SGEs on the largest NFS request that can be sent or received.
In the transport layer, the limit is actually based on the
capabilities of the underlying device, not on properties of the
Upper Layer Protocol.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

svcrdma: Introduce svc_rdma_send_ctxt

2018-05-11T19:48:57+00:00

svc_rdma_op_ctxt's are pre-allocated and maintained on a per-xprt
free list. This eliminates the overhead of calling kmalloc / kfree,
both of which grab a globally shared lock that disables interrupts.
Introduce a replacement to svc_rdma_op_ctxt's that is built
especially for the svcrdma Send path.

Subsequent patches will take advantage of this new structure by
allocating real resources which are then cached in these objects.
The allocations are freed when the transport is torn down.

I've renamed the structure so that static type checking can be used
to ensure that uses of op_ctxt and send_ctxt are not confused. As an
additional clean up, structure fields are renamed to conform with
kernel coding conventions.

Additional clean ups:
- Handle svc_rdma_send_ctxt_get allocation failure at each call
  site, rather than pre-allocating and hoping we guessed correctly
- All send_ctxt_put call-sites request page freeing, so remove
  the @free_pages argument
- All send_ctxt_put call-sites unmap SGEs, so fold that into
  svc_rdma_send_ctxt_put

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

svcrdma: Clean up Send SGE accounting

2018-05-11T19:48:57+00:00

Clean up: Since there's already a svc_rdma_op_ctxt being passed
around with the running count of mapped SGEs, drop unneeded
parameters to svc_rdma_post_send_wr().

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields

svcrdma: Refactor svc_rdma_dma_map_buf

2018-05-11T19:48:57+00:00

Clean up: svc_rdma_dma_map_buf does mostly the same thing as
svc_rdma_dma_map_page, so let's fold these together.

Signed-off-by: Chuck Lever 
Signed-off-by: J. Bruce Fields