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From:   "NeilBrown" <neilb@suse.de>
To:     "Chuck Lever III" <chuck.lever@oracle.com>
Cc:     "Bruce Fields" <bfields@fieldses.org>,
        "Scott Mayhew" <smayhew@redhat.com>,
        "Timothy Pearson" <tpearson@raptorengineering.com>,
        "Linux NFS Mailing List" <linux-nfs@vger.kernel.org>,
        "Trond Myklebust" <trondmy@gmail.com>
Subject: Re: CPU stall, eventual host hang with BTRFS + NFS under heavy load
In-reply-to: <34A4C7EB-2798-4482-A786-90161F5F9E34@oracle.com>
References: <281642234.3818.1625478269194.JavaMail.zimbra@raptorengineeringinc.com>,
 <162855621114.22632.14151019687856585770@noble.neil.brown.name>,
 <20210812144428.GA9536@fieldses.org>,
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 <YWCpnsdVqssFaLrf@aion.usersys.redhat.com>,
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 <34A4C7EB-2798-4482-A786-90161F5F9E34@oracle.com>
Date:   Tue, 12 Oct 2021 08:57:47 +1100
Message-id: <163398946770.17149.14605560717849885454@noble.neil.brown.name>
Precedence: bulk

On Tue, 12 Oct 2021, Chuck Lever III wrote:
> 
> Scott seems well positioned to identify a reproducer. Maybe we
> can give him some likely candidates for possible bugs to explore
> first.

Has this patch been tried?

NeilBrown


diff --git a/net/sunrpc/sched.c b/net/sunrpc/sched.c
index c045f63d11fa..308f5961cb78 100644
--- a/net/sunrpc/sched.c
+++ b/net/sunrpc/sched.c
@@ -814,6 +814,7 @@ rpc_reset_task_statistics(struct rpc_task *task)
 {
 	task->tk_timeouts = 0;
 	task->tk_flags &= ~(RPC_CALL_MAJORSEEN|RPC_TASK_SENT);
+	clear_bit(RPC_TASK_SIGNALLED, &task->tk_runstate);
 	rpc_init_task_statistics(task);
 }