+ sunrpc-refresh-rq_pages-using-a-bulk-page-allocator.patch added to -mm tree

+ sunrpc-refresh-rq_pages-using-a-bulk-page-allocator.patch added to -mm tree

[akpm]

The patch titled
     Subject: SUNRPC: refresh rq_pages using a bulk page allocator
has been added to the -mm tree.  Its filename is
     sunrpc-refresh-rq_pages-using-a-bulk-page-allocator.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/sunrpc-refresh-rq_pages-using-a-bulk-page-allocator.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/sunrpc-refresh-rq_pages-using-a-bulk-page-allocator.patch

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------------------------------------------------------
From: Chuck Lever <chuck.lever@oracle.com>
Subject: 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: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reviewed-by: Alexander 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: Andrew Morton <akpm@linux-foundation.org>
---

 net/sunrpc/svc_xprt.c |   31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

--- a/net/sunrpc/svc_xprt.c~sunrpc-refresh-rq_pages-using-a-bulk-page-allocator
+++ a/net/sunrpc/svc_xprt.c
@@ -643,30 +643,29 @@ static int svc_alloc_arg(struct svc_rqst
 {
 	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) {
-				set_current_state(TASK_INTERRUPTIBLE);
-				if (signalled() || kthread_should_stop()) {
-					set_current_state(TASK_RUNNING);
-					return -EINTR;
-				}
-				schedule_timeout(msecs_to_jiffies(500));
-			}
-			rqstp->rq_pages[i] = 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);
+			return -EINTR;
 		}
+		schedule_timeout(msecs_to_jiffies(500));
+	}
 	rqstp->rq_page_end = &rqstp->rq_pages[pages];
 	rqstp->rq_pages[pages] = NULL; /* this might be seen in nfsd_splice_actor() */
 
_

Patches currently in -mm which might be from chuck.lever@oracle.com are

sunrpc-set-rq_page_end-differently.patch
sunrpc-refresh-rq_pages-using-a-bulk-page-allocator.patch