From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E59F714600E; Thu, 11 Apr 2024 10:24:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712831079; cv=none; b=XrWBD+olkZdINvk0JnfKx/mJ1eVNCGAt1MnBYKvpZ+2a8pZAqXxB3DHUPr1cU0hXFuH21S4MbXGnuh2Tdd18a82Hu8JWhEAwbI9kRBr1+l5L2cVgoW1dQPr8wd5G/NPZDhvGVTr7WWp2DMLbgmFAkwO+vzvtU/sdmQouwljJz5o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712831079; c=relaxed/simple; bh=fSqc5PZHJVXCxX98xwzsi5QrLE7JoUejIAcyIyVbrrk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=K0Le8dEQT0qZ3IGh9jQFXo8xl4Jfuq0BSB2PI+cVnM06llfHgBwcLJkFOUQjELkFbE+EvM8mxH6g74UMVjjZICg0bD/KmaWKcrm7PprzPR/BAMHstRssrukioxdCH92RTT6BO3guzc5yLHV8TaozVe5+PPKQ8FTWIQHifO1wO1c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Eyc3gPiZ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Eyc3gPiZ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5F6B3C43394; Thu, 11 Apr 2024 10:24:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712831078; bh=fSqc5PZHJVXCxX98xwzsi5QrLE7JoUejIAcyIyVbrrk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Eyc3gPiZ8qaOGmBEKBoIHRKShQ7fz36Cw6TK9Vb0MxVKoS1WlAE2UGBYz82E6A/Ya /gISQLIhyhwIf47WcP/hP9v4sCTGT3jZ3yy/D2NHAC9m4dLf0EG7MREyAfFpnyhqHT 6xnEQ+naqx05dyAZc7Bq9fuXvFlaa+kdoY8GqDlI= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dai Ngo , Jeff Layton , Trond Myklebust , Sasha Levin Subject: [PATCH 5.4 191/215] SUNRPC: increase size of rpc_wait_queue.qlen from unsigned short to unsigned int Date: Thu, 11 Apr 2024 11:56:40 +0200 Message-ID: <20240411095430.604371983@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240411095424.875421572@linuxfoundation.org> References: <20240411095424.875421572@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dai Ngo [ Upstream commit 2c35f43b5a4b9cdfaa6fdd946f5a212615dac8eb ] When the NFS client is under extreme load the rpc_wait_queue.qlen counter can be overflowed. Here is an instant of the backlog queue overflow in a real world environment shown by drgn helper: rpc_task_stats(rpc_clnt): ------------------------- rpc_clnt: 0xffff92b65d2bae00 rpc_xprt: 0xffff9275db64f000 Queue: sending[64887] pending[524] backlog[30441] binding[0] XMIT task: 0xffff925c6b1d8e98 WRITE: 750654 __dta_call_status_580: 65463 __dta_call_transmit_status_579: 1 call_reserveresult: 685189 nfs_client_init_is_complete: 1 COMMIT: 584 call_reserveresult: 573 __dta_call_status_580: 11 ACCESS: 1 __dta_call_status_580: 1 GETATTR: 10 __dta_call_status_580: 4 call_reserveresult: 6 751249 tasks for server 111.222.333.444 Total tasks: 751249 count_rpc_wait_queues(xprt): ---------------------------- **** rpc_xprt: 0xffff9275db64f000 num_reqs: 65511 wait_queue: xprt_binding[0] cnt: 0 wait_queue: xprt_binding[1] cnt: 0 wait_queue: xprt_binding[2] cnt: 0 wait_queue: xprt_binding[3] cnt: 0 rpc_wait_queue[xprt_binding].qlen: 0 maxpriority: 0 wait_queue: xprt_sending[0] cnt: 0 wait_queue: xprt_sending[1] cnt: 64887 wait_queue: xprt_sending[2] cnt: 0 wait_queue: xprt_sending[3] cnt: 0 rpc_wait_queue[xprt_sending].qlen: 64887 maxpriority: 3 wait_queue: xprt_pending[0] cnt: 524 wait_queue: xprt_pending[1] cnt: 0 wait_queue: xprt_pending[2] cnt: 0 wait_queue: xprt_pending[3] cnt: 0 rpc_wait_queue[xprt_pending].qlen: 524 maxpriority: 0 wait_queue: xprt_backlog[0] cnt: 0 wait_queue: xprt_backlog[1] cnt: 685801 wait_queue: xprt_backlog[2] cnt: 0 wait_queue: xprt_backlog[3] cnt: 0 rpc_wait_queue[xprt_backlog].qlen: 30441 maxpriority: 3 [task cnt mismatch] There is no effect on operations when this overflow occurs. However it causes confusion when trying to diagnose the performance problem. Signed-off-by: Dai Ngo Reviewed-by: Jeff Layton Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- include/linux/sunrpc/sched.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/linux/sunrpc/sched.h b/include/linux/sunrpc/sched.h index 5c37fabdec103..61de83be9cc27 100644 --- a/include/linux/sunrpc/sched.h +++ b/include/linux/sunrpc/sched.h @@ -196,7 +196,7 @@ struct rpc_wait_queue { unsigned char maxpriority; /* maximum priority (0 if queue is not a priority queue) */ unsigned char priority; /* current priority */ unsigned char nr; /* # tasks remaining for cookie */ - unsigned short qlen; /* total # tasks waiting in queue */ + unsigned int qlen; /* total # tasks waiting in queue */ struct rpc_timer timer_list; #if IS_ENABLED(CONFIG_SUNRPC_DEBUG) || IS_ENABLED(CONFIG_TRACEPOINTS) const char * name; -- 2.43.0