From: Chuck Lever III <chuck.lever@oracle.com>
To: Mel Gorman <mgorman@techsingularity.net>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Jesper Dangaard Brouer <brouer@redhat.com>,
Christoph Hellwig <hch@infradead.org>,
LKML <linux-kernel@vger.kernel.org>,
Linux-Net <netdev@vger.kernel.org>, Linux-MM <linux-mm@kvack.org>,
Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH 3/5] SUNRPC: Refresh rq_pages using a bulk page allocator
Date: Thu, 11 Mar 2021 14:23:53 +0000 [thread overview]
Message-ID: <8F34578A-A5AC-4D6A-BF32-1578B14FDE45@oracle.com> (raw)
In-Reply-To: <20210311114935.11379-4-mgorman@techsingularity.net>
> On Mar 11, 2021, at 6:49 AM, Mel Gorman <mgorman@techsingularity.net> wrote:
>
> From: Chuck Lever <chuck.lever@oracle.com>
>
> Reduce the rate at which nfsd threads hammer on the page allocator.
> This improve throughput scalability by enabling the threads to run
> more independently of each other.
Mel, if you should repost this series: ^improve^improves
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
> ---
> net/sunrpc/svc_xprt.c | 43 +++++++++++++++++++++++++++++++------------
> 1 file changed, 31 insertions(+), 12 deletions(-)
>
> diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
> index cfa7e4776d0e..38a8d6283801 100644
> --- a/net/sunrpc/svc_xprt.c
> +++ b/net/sunrpc/svc_xprt.c
> @@ -642,11 +642,12 @@ static void svc_check_conn_limits(struct svc_serv *serv)
> static int svc_alloc_arg(struct svc_rqst *rqstp)
> {
> struct svc_serv *serv = rqstp->rq_server;
> + unsigned long needed;
> struct xdr_buf *arg;
> + struct page *page;
> int pages;
> int i;
>
> - /* 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",
> @@ -654,19 +655,28 @@ static int svc_alloc_arg(struct svc_rqst *rqstp)
> /* 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));
> +
> + for (needed = 0, i = 0; i < pages ; i++)
> + if (!rqstp->rq_pages[i])
> + needed++;
> + if (needed) {
> + LIST_HEAD(list);
> +
> +retry:
> + alloc_pages_bulk(GFP_KERNEL, needed, &list);
> + for (i = 0; i < pages; i++) {
> + if (!rqstp->rq_pages[i]) {
> + page = list_first_entry_or_null(&list,
> + struct page,
> + lru);
> + if (unlikely(!page))
> + goto empty_list;
> + list_del(&page->lru);
> + rqstp->rq_pages[i] = page;
> + needed--;
> }
> - 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() */
>
> @@ -681,6 +691,15 @@ static int svc_alloc_arg(struct svc_rqst *rqstp)
> arg->len = (pages-1)*PAGE_SIZE;
> arg->tail[0].iov_len = 0;
> return 0;
> +
> +empty_list:
> + set_current_state(TASK_INTERRUPTIBLE);
> + if (signalled() || kthread_should_stop()) {
> + set_current_state(TASK_RUNNING);
> + return -EINTR;
> + }
> + schedule_timeout(msecs_to_jiffies(500));
> + goto retry;
> }
>
> static bool
> --
> 2.26.2
>
--
Chuck Lever
next prev parent reply other threads:[~2021-03-11 14:25 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-03-11 11:49 [PATCH 0/5 v3] Introduce a bulk order-0 page allocator with two in-tree users Mel Gorman
2021-03-11 11:49 ` [PATCH 1/5] SUNRPC: Set rq_page_end differently Mel Gorman
2021-03-11 11:49 ` [PATCH 2/5] mm/page_alloc: Add a bulk page allocator Mel Gorman
2021-03-11 16:42 ` Alexander Duyck
2021-03-12 7:32 ` Mel Gorman
2021-03-11 11:49 ` [PATCH 3/5] SUNRPC: Refresh rq_pages using " Mel Gorman
2021-03-11 14:23 ` Chuck Lever III [this message]
2021-03-11 11:49 ` [PATCH 4/5] net: page_pool: refactor dma_map into own function page_pool_dma_map Mel Gorman
2021-03-11 11:49 ` [PATCH 5/5] net: page_pool: use alloc_pages_bulk in refill code path Mel Gorman
-- strict thread matches above, loose matches on Subject: below --
2021-03-10 10:46 [PATCH 0/5] Introduce a bulk order-0 page allocator with two in-tree users Mel Gorman
2021-03-10 10:46 ` [PATCH 3/5] SUNRPC: Refresh rq_pages using a bulk page allocator Mel Gorman
2021-03-01 16:11 [PATCH 0/5] Introduce a bulk order-0 page allocator with two in-tree users Mel Gorman
2021-03-01 16:11 ` [PATCH 3/5] SUNRPC: Refresh rq_pages using a bulk page allocator Mel Gorman
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