Commit f6e70aab authored by Chuck Lever's avatar Chuck Lever Committed by Linus Torvalds
Browse files

SUNRPC: refresh rq_pages using a bulk page allocator 

Reduce the rate at which nfsd threads hammer on the page allocator.  This
improves throughput scalability by enabling the threads to run more
independently of each other.

[mgorman: Update interpretation of alloc_pages_bulk return value]

Link: https://lkml.kernel.org/r/20210325114228.27719-8-mgorman@techsingularity.net


Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
Reviewed-by: default avatarAlexander Lobakin <alobakin@pm.me>
Cc: Alexander Duyck <alexander.duyck@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: David Miller <davem@davemloft.net>
Cc: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent ab836264

net/sunrpc/svc_xprt.c

+15 −16
Original line number Diff line number Diff line
@@ -662,21 +662,22 @@ static int svc_alloc_arg(struct svc_rqst *rqstp) 
{

	struct svc_serv *serv = rqstp->rq_server;

	struct xdr_buf *arg = &rqstp->rq_arg;

	int pages;

	int i;

	unsigned long pages, filled;



	/* now allocate needed pages.  If we get a failure, sleep briefly */

	pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT;

	if (pages > RPCSVC_MAXPAGES) {

		pr_warn_once("svc: warning: pages=%u > RPCSVC_MAXPAGES=%lu\n",

		pr_warn_once("svc: warning: pages=%lu > RPCSVC_MAXPAGES=%lu\n",

			     pages, RPCSVC_MAXPAGES);

		/* use as many pages as possible */

		pages = RPCSVC_MAXPAGES;

	}

	for (i = 0; i < pages ; i++)

		while (rqstp->rq_pages[i] == NULL) {

			struct page *p = alloc_page(GFP_KERNEL);

			if (!p) {



	for (;;) {

		filled = alloc_pages_bulk_array(GFP_KERNEL, pages,

						rqstp->rq_pages);

		if (filled == pages)

			break;



		set_current_state(TASK_INTERRUPTIBLE);

		if (signalled() || kthread_should_stop()) {

			set_current_state(TASK_RUNNING);
@@ -684,8 +685,6 @@ static int svc_alloc_arg(struct svc_rqst *rqstp) 
		}

		schedule_timeout(msecs_to_jiffies(500));

	}

			rqstp->rq_pages[i] = p;

		}

	rqstp->rq_page_end = &rqstp->rq_pages[pages];

	rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */