Commit 647a2a64 authored Apr 14, 2023 by Chuck Lever

SUNRPC: Convert svc_xprt_release() to the release_pages() API



Instead of invoking put_page() one-at-a-time, pass the "response"
portion of rq_pages directly to release_pages() to reduce the number
of times each nfsd thread invokes a page allocator API.

Since svc_xprt_release() is not invoked while a client is waiting
for an RPC Reply, this is not expected to directly impact mean
request latencies on a lightly or moderately loaded server. However
as workload intensity increases, I expect somewhat better
scalability: the same number of server threads should be able to
handle more work.

Reviewed-by: Calum Mackay <calum.mackay@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

parent b20cb39d

net/sunrpc/svc.c

+5 −6

Original line number	Diff line number	Diff line
		@@ -878,13 +878,12 @@ EXPORT_SYMBOL_GPL(svc_rqst_replace_page);
		*/
		void svc_rqst_release_pages(struct svc_rqst *rqstp)
		{
		while (rqstp->rq_next_page != rqstp->rq_respages) {
		struct page **pp = --rqstp->rq_next_page;
		int i, count = rqstp->rq_next_page - rqstp->rq_respages;

		if (*pp) {
		put_page(*pp);
		*pp = NULL;
		}
		if (count) {
		release_pages(rqstp->rq_respages, count);
		for (i = 0; i < count; i++)
		rqstp->rq_respages[i] = NULL;
		}
		}