Commit 26c8e6eb authored by Chuck Lever's avatar Chuck Lever
Browse files

svcrdma: preserve rq_next_page in svc_rdma_save_io_pages 



svc_rdma_save_io_pages() transfers response pages to the send
context and sets those slots to NULL. It then resets rq_next_page to
equal rq_respages, hiding the NULL region from
svc_rqst_release_pages().

Now that svc_rqst_release_pages() handles NULL entries, this reset
is no longer necessary. Removing it preserves the invariant that the
range [rq_respages, rq_next_page) accurately describes how many
response pages were consumed, enabling a subsequent optimization in
svc_alloc_arg() that refills only the consumed range.

Reviewed-by: default avatarJeff Layton <jlayton@kernel.org>
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
parent 22cc2ba5

net/sunrpc/xprtrdma/svc_rdma_sendto.c

+2 −4
Original line number Diff line number Diff line
@@ -858,7 +858,8 @@ int svc_rdma_map_reply_msg(struct svcxprt_rdma *rdma, 


/* The svc_rqst and all resources it owns are released as soon as

 * svc_rdma_sendto returns. Transfer pages under I/O to the ctxt

 * so they are released by the Send completion handler.

 * so they are released only after Send completion, and not by

 * svc_rqst_release_pages().

 */

static void svc_rdma_save_io_pages(struct svc_rqst *rqstp,

				   struct svc_rdma_send_ctxt *ctxt)
@@ -870,9 +871,6 @@ static void svc_rdma_save_io_pages(struct svc_rqst *rqstp, 
		ctxt->sc_pages[i] = rqstp->rq_respages[i];

		rqstp->rq_respages[i] = NULL;

	}



	/* Prevent svc_xprt_release from releasing pages in rq_pages */

	rqstp->rq_next_page = rqstp->rq_respages;

}



/* Prepare the portion of the RPC Reply that will be transmitted