Commit 6550abba authored by Jim Harris's avatar Jim Harris
Browse files

nvme: prefetch stailq before freeing pcie request 



We will need to put the recently completed nvme_request
object on the qpair's STAILQ.  We don't reference any
real data from the nvme_request in the completion path
since we've already stashed the cb_fn and cb_arg in
the nvme_tracker.  But we will need to reference the
STAILQ_ENTRY to put it back in the qpair's STAILQ, so
prefetch that cacheline.

Signed-off-by: default avatarJim Harris <james.r.harris@intel.com>
Change-Id: Id76122afe4150c84a61fbe38bc874f10d606b3b3

Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/456673


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
parent b3d884b7

lib/nvme/nvme_pcie.c

+4 −0
Original line number Diff line number Diff line
@@ -2094,6 +2094,10 @@ nvme_pcie_qpair_process_completions(struct spdk_nvme_qpair *qpair, uint32_t max_ 
		}



		tr = &pqpair->tr[cpl->cid];

		/* Prefetch the req's STAILQ_ENTRY since we'll need to access it

		 * as part of putting the req back on the qpair's free list.

		 */

		__builtin_prefetch(&tr->req->stailq);

		pqpair->sq_head = cpl->sqhd;



		if (tr->req) {