Received-SPF: pass (google.com: domain of linux-nfs-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Wed, 24 Aug 2022 12:20:56 +0300
From:   Leon Romanovsky <leon@kernel.org>
To:     Chuck Lever III <chuck.lever@oracle.com>,
        Jason Gunthorpe <jgg@nvidia.com>
Cc:     Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
        "linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>
Subject: Re: [PATCH v1] RDMA/core: Fix check_flush_dependency splat on addr_wq
Message-ID: <YwXtePKW+sn/89M6@unreal>
References: <166118222093.3250511.11454048195824271658.stgit@morisot.1015granger.net>
 <YwSLOxyEtV4l2Frc@unreal>
 <584E7212-BC09-48E1-A27E-725E54FA075E@oracle.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <584E7212-BC09-48E1-A27E-725E54FA075E@oracle.com>
Precedence: bulk

On Tue, Aug 23, 2022 at 01:58:44PM +0000, Chuck Lever III wrote:
> 
> 
> > On Aug 23, 2022, at 4:09 AM, Leon Romanovsky <leon@kernel.org> wrote:
> > 
> > On Mon, Aug 22, 2022 at 11:30:20AM -0400, Chuck Lever wrote:

<...>

> >> The xprtiod work queue is WQ_MEM_RECLAIM, so any work queue that
> >> one of its work items tries to cancel has to be WQ_MEM_RECLAIM to
> >> prevent a priority inversion.
> > 
> > But why do you have WQ_MEM_RECLAIM in xprtiod?
> 
> Because RPC is under a filesystem (NFS). Therefore it has to handle
> writeback demanded by direct reclaim. All of the storage ULPs have
> this constraint, in fact.

I don't know, this ib_addr workqueue is used when connection is created.
Jason, what do you think?

Thanks