[PATCH v3 07/12] xprtrdma: Refactor FRMR invalidation

Chuck Lever
2016-11-29T15:52:57Z

Clean up: After some recent updates, clarifications can be made to
the FRMR invalidation logic.

- Both the remote and local invalidation case mark the frmr INVALID,
so make that a common path.

- Manage the WR list more "tastefully" by replacing the conditional
that discriminates between the list head and ->next pointers.

- Use mw->mw_handle in all cases, since that has the same value as
f->fr_mr->rkey, and is already in cache.

Signed-off-by: Chuck Lever <chuck.lever-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>
---
net/sunrpc/xprtrdma/frwr_ops.c | 57 +++++++++++++++-------------------------
1 file changed, 21 insertions(+), 36 deletions(-)

diff --git a/net/sunrpc/xprtrdma/frwr_ops.c b/net/sunrpc/xprtrdma/frwr_ops.c
index e99bf61..900dc40 100644
--- a/net/sunrpc/xprtrdma/frwr_ops.c
+++ b/net/sunrpc/xprtrdma/frwr_ops.c
@@ -457,26 +457,6 @@
return -ENOTCONN;
}

-static struct ib_send_wr *
-__frwr_prepare_linv_wr(struct rpcrdma_mw *mw)
-{
- struct rpcrdma_frmr *f = &mw->frmr;
- struct ib_send_wr *invalidate_wr;
-
- dprintk("RPC: %s: invalidating frmr %p\n", __func__, f);
-
- f->fr_state = FRMR_IS_INVALID;
- invalidate_wr = &f->fr_invwr;
-
- memset(invalidate_wr, 0, sizeof(*invalidate_wr));
- f->fr_cqe.done = frwr_wc_localinv;
- invalidate_wr->wr_cqe = &f->fr_cqe;
- invalidate_wr->opcode = IB_WR_LOCAL_INV;
- invalidate_wr->ex.invalidate_rkey = f->fr_mr->rkey;
-
- return invalidate_wr;
-}
-
/* Invalidate all memory regions that were registered for "req".
*
* Sleeps until it is safe for the host CPU to access the
@@ -487,7 +467,7 @@
static void
frwr_op_unmap_sync(struct rpcrdma_xprt *r_xprt, struct rpcrdma_req *req)
{
- struct ib_send_wr *invalidate_wrs, *pos, *prev, *bad_wr;
+ struct ib_send_wr *first, **prev, *last, *bad_wr;
struct rpcrdma_rep *rep = req->rl_reply;
struct rpcrdma_ia *ia = &r_xprt->rx_ia;
struct rpcrdma_mw *mw, *tmp;
@@ -503,23 +483,28 @@
*/
f = NULL;
count = 0;
- invalidate_wrs = pos = prev = NULL;
+ prev = &first;
list_for_each_entry(mw, &req->rl_registered, mw_list) {
+ mw->frmr.fr_state = FRMR_IS_INVALID;
+
if ((rep->rr_wc_flags & IB_WC_WITH_INVALIDATE) &&
- (mw->mw_handle == rep->rr_inv_rkey)) {
- mw->frmr.fr_state = FRMR_IS_INVALID;
+ (mw->mw_handle == rep->rr_inv_rkey))
continue;
- }

- pos = __frwr_prepare_linv_wr(mw);
+ f = &mw->frmr;
+ dprintk("RPC: %s: invalidating frmr %p\n",
+ __func__, f);
+
+ f->fr_cqe.done = frwr_wc_localinv;
+ last = &f->fr_invwr;
+ memset(last, 0, sizeof(*last));
+ last->wr_cqe = &f->fr_cqe;
+ last->opcode = IB_WR_LOCAL_INV;
+ last->ex.invalidate_rkey = mw->mw_handle;
count++;

- if (!invalidate_wrs)
- invalidate_wrs = pos;
- else
- prev->next = pos;
- prev = pos;
- f = &mw->frmr;
+ *prev = last;
+ prev = &last->next;
}
if (!f)
goto unmap;
@@ -528,7 +513,7 @@
* last WR in the chain completes, all WRs in the chain
* are complete.
*/
- f->fr_invwr.send_flags = IB_SEND_SIGNALED;
+ last->send_flags = IB_SEND_SIGNALED;
f->fr_cqe.done = frwr_wc_localinv_wake;
reinit_completion(&f->fr_linv_done);

@@ -543,7 +528,7 @@
* unless ri_id->qp is a valid pointer.
*/
r_xprt->rx_stats.local_inv_needed++;
- rc = ib_post_send(ia->ri_id->qp, invalidate_wrs, &bad_wr);
+ rc = ib_post_send(ia->ri_id->qp, first, &bad_wr);
if (rc)
goto reset_mrs;

@@ -554,7 +539,7 @@
*/
unmap:
list_for_each_entry_safe(mw, tmp, &req->rl_registered, mw_list) {
- dprintk("RPC: %s: unmapping frmr %p\n",
+ dprintk("RPC: %s: DMA unmapping frmr %p\n",
__func__, &mw->frmr);
list_del_init(&mw->mw_list);
ib_dma_unmap_sg(ia->ri_device,
@@ -572,7 +557,7 @@
*/
list_for_each_entry(mw, &req->rl_registered, mw_list) {
f = &mw->frmr;
- if (mw->frmr.fr_mr->rkey == bad_wr->ex.invalidate_rkey) {
+ if (mw->mw_handle == bad_wr->ex.invalidate_rkey) {
__frwr_reset_mr(ia, mw);
bad_wr = bad_wr->next;
}

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