From: bfields@fieldses.org (J. Bruce Fields)
To: NeilBrown <neilb@suse.de>
Cc: Chuck Lever III <chuck.lever@oracle.com>,
Mike Javorski <mike.javorski@gmail.com>,
Mel Gorman <mgorman@suse.com>,
Linux NFS Mailing List <linux-nfs@vger.kernel.org>
Subject: Re: [PATCH] SUNRPC: don't pause on incomplete allocation
Date: Mon, 30 Aug 2021 16:46:16 -0400 [thread overview]
Message-ID: <20210830204616.GA13399@fieldses.org> (raw)
In-Reply-To: <163027659478.7591.8897815399981483759@noble.neil.brown.name>
For what it's worth, another positive report on this patch:
https://bugzilla.kernel.org/show_bug.cgi?id=213869#c10
--b.
On Mon, Aug 30, 2021 at 08:36:34AM +1000, NeilBrown wrote:
>
> alloc_pages_bulk_array() attempts to allocate at least one page based on
> the provided pages, and then opportunistically allocates more if that
> can be done without dropping the spinlock.
>
> So if it returns fewer than requested, that could just mean that it
> needed to drop the lock. In that case, try again immediately.
>
> Only pause for a time if no progress could be made.
>
> Reported-and-tested-by: Mike Javorski <mike.javorski@gmail.com>
> Reported-and-tested-by: Lothar Paltins <lopa@mailbox.org>
> Fixes: f6e70aab9dfe ("SUNRPC: refresh rq_pages using a bulk page allocator")
> Signed-off-by: NeilBrown <neilb@suse.de>
> ---
>
> I decided I would resend, as I thought the for() loops could be clearer.
> This patch should perform exactly the same as the previous one.
>
>
> net/sunrpc/svc_xprt.c | 13 +++++++------
> 1 file changed, 7 insertions(+), 6 deletions(-)
>
> diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
> index d66a8e44a1ae..e74d5cf3cbb4 100644
> --- a/net/sunrpc/svc_xprt.c
> +++ b/net/sunrpc/svc_xprt.c
> @@ -662,7 +662,7 @@ static int svc_alloc_arg(struct svc_rqst *rqstp)
> {
> struct svc_serv *serv = rqstp->rq_server;
> struct xdr_buf *arg = &rqstp->rq_arg;
> - unsigned long pages, filled;
> + unsigned long pages, filled, ret;
>
> pages = (serv->sv_max_mesg + 2 * PAGE_SIZE) >> PAGE_SHIFT;
> if (pages > RPCSVC_MAXPAGES) {
> @@ -672,11 +672,12 @@ static int svc_alloc_arg(struct svc_rqst *rqstp)
> pages = RPCSVC_MAXPAGES;
> }
>
> - for (;;) {
> - filled = alloc_pages_bulk_array(GFP_KERNEL, pages,
> - rqstp->rq_pages);
> - if (filled == pages)
> - break;
> + for (filled = 0; filled < pages; filled = ret) {
> + ret = alloc_pages_bulk_array(GFP_KERNEL, pages,
> + rqstp->rq_pages);
> + if (ret > filled)
> + /* Made progress, don't sleep yet */
> + continue;
>
> set_current_state(TASK_INTERRUPTIBLE);
> if (signalled() || kthread_should_stop()) {
> --
> 2.32.0
next prev parent reply other threads:[~2021-08-30 20:46 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-08 22:37 NFS server regression in kernel 5.13 (tested w/ 5.13.9) Mike Javorski
2021-08-08 22:47 ` Chuck Lever III
2021-08-08 23:23 ` Mike Javorski
2021-08-09 0:01 ` NeilBrown
2021-08-09 0:28 ` Mike Javorski
2021-08-10 0:50 ` Mike Javorski
2021-08-10 1:28 ` NeilBrown
2021-08-10 11:54 ` Daire Byrne
2021-08-13 1:51 ` Mike Javorski
2021-08-13 2:39 ` NeilBrown
2021-08-13 2:53 ` Mike Javorski
2021-08-15 1:23 ` Mike Javorski
2021-08-16 1:20 ` NeilBrown
2021-08-16 13:21 ` Chuck Lever III
2021-08-16 16:25 ` Mike Javorski
2021-08-16 23:01 ` NeilBrown
2021-08-20 0:31 ` NeilBrown
2021-08-20 0:52 ` Mike Javorski
2021-08-22 0:17 ` Mike Javorski
2021-08-22 3:41 ` NeilBrown
2021-08-22 4:05 ` Mike Javorski
2021-08-22 22:00 ` NeilBrown
2021-08-26 19:34 ` Mike Javorski
2021-08-26 21:44 ` NeilBrown
2021-08-27 0:07 ` Mike Javorski
2021-08-27 5:27 ` NeilBrown
2021-08-27 6:11 ` Mike Javorski
2021-08-27 7:14 ` NeilBrown
2021-08-27 14:13 ` Chuck Lever III
2021-08-27 17:07 ` Mike Javorski
2021-08-27 22:00 ` Mike Javorski
2021-08-27 23:49 ` Chuck Lever III
2021-08-28 3:22 ` Mike Javorski
2021-08-28 18:23 ` Chuck Lever III
2021-08-29 22:36 ` [PATCH] SUNRPC: don't pause on incomplete allocation NeilBrown
2021-08-30 9:12 ` Mel Gorman
2021-08-30 20:46 ` J. Bruce Fields [this message]
[not found] ` <163027609524.7591.4987241695872857175@noble.neil.brown.name>
2021-08-30 9:11 ` [PATCH] MM: clarify effort used in alloc_pages_bulk_*() Mel Gorman
2021-09-04 17:41 ` NFS server regression in kernel 5.13 (tested w/ 5.13.9) Mike Javorski
2021-09-05 2:02 ` Chuck Lever III
2021-09-16 2:45 ` Mike Javorski
2021-09-16 18:58 ` Chuck Lever III
2021-09-16 19:21 ` Mike Javorski
2021-09-17 14:41 ` J. Bruce Fields
2021-08-16 16:09 ` Mike Javorski
2021-08-16 23:04 ` NeilBrown
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