From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C8E3C4167D for ; Mon, 25 Apr 2022 22:22:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238088AbiDYWZP (ORCPT ); Mon, 25 Apr 2022 18:25:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46904 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1343668AbiDYWFJ (ORCPT ); Mon, 25 Apr 2022 18:05:09 -0400 Received: from out1.migadu.com (out1.migadu.com [IPv6:2001:41d0:2:863f::]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 87ECD2AED for ; Mon, 25 Apr 2022 15:02:03 -0700 (PDT) Message-ID: <8d8413e4-d30c-9e65-914e-231cc8e9784a@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1650924121; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=1R1E/JDRb2Oy45G5VOjsCxH3aTtrWflbwZKm9fp/FkU=; b=ViQKDPXPyd9xpfqfwoqkyQfRPtVLjopwRlKKkSMNCBJVK8NqQV6jyjWuGowNSryzE7gc8V ww674yni/PbWiusHnHHq6I+EGplk1T++upDuD1FM1u1GHiCPqUdBA5JXBb9IYGnupI1rFS tkP1146pry/zhaset0Y7cDmKaXdm5jQ= Date: Tue, 26 Apr 2022 06:01:51 +0800 MIME-Version: 1.0 Subject: Re: [PATCHv6 1/4] RDMA/rxe: Fix dead lock caused by __rxe_add_to_pool interrupted by rxe_pool_get_index To: Jason Gunthorpe Cc: "Pearson, Robert B" , "leon@kernel.org" , "linux-rdma@vger.kernel.org" , Yi Zhang References: <20220422194416.983549-1-yanjun.zhu@linux.dev> <79753213-60cc-87bf-b0e6-b9c6a29209a3@linux.dev> <20220425190227.GX64706@ziepe.ca> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yanjun Zhu In-Reply-To: <20220425190227.GX64706@ziepe.ca> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org 在 2022/4/26 3:02, Jason Gunthorpe 写道: > On Mon, Apr 25, 2022 at 07:47:23AM +0800, Yanjun Zhu wrote: >> 在 2022/4/22 23:57, Pearson, Robert B 写道: >>> Use of rcu_read_lock solves this problem. Rcu_read_lock and spinlock on same data can >>> Co-exist at the same time. That is the whole point. All this is going away soon. >> This is based on your unproved assumption. > No, Bob is right, RCU avoids the need for a BH lock on this XA, the > only remaining issue is the AH creation atomic call path. If RCU is used, the similar issues like AH creation atomic call path will become more. Zhu Yanjun > > Jason