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From: Jason Gunthorpe <jgg@ziepe.ca>
To: Shifeng Li <lishifeng@sangfor.com.cn>
Cc: Ding Hui <dinghui@sangfor.com.cn>,
	leon@kernel.org, wenglianfa@huawei.com, gustavoars@kernel.org,
	linux-rdma@vger.kernel.org, linux-kernel@vger.kernel.org,
	Shifeng Li <lishifeng1992@126.com>
Subject: Re: [PATCH] RDMA/device: Fix a race between mad_client and cm_client init
Date: Wed, 31 Jan 2024 20:04:08 -0400	[thread overview]
Message-ID: <20240201000408.GG50608@ziepe.ca> (raw)
In-Reply-To: <5bc6ed6d-31e9-4b44-aa91-5f9d0f3d92c8@sangfor.com.cn>

On Fri, Jan 26, 2024 at 10:25:01AM +0800, Shifeng Li wrote:
> > I believe this modification is effective, rather than expanding the clients_rwsem range,
> > the key point is down_write(&devices_rwsem), which prevents ib_register_client() from
> > being executed in the gap of ib_register_device().
> > 
> > However, this may cause a little confusion, as ib_register_client() does not modify
> > anything related to devices, but it is protected by a write lock.
> > 
> Do you have any differing opinions about above?

I'd rather see the client side have a comment explaining the confusing
lock then disturb the locking on the devices side..

I think the write/read lock scheme there was done for a reason I just
haven't had time to recall exactly why..

Please send a patch with this arrangement

Jason

      reply	other threads:[~2024-02-01  0:04 UTC|newest]

Thread overview: 14+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-02  3:43 [PATCH] RDMA/device: Fix a race between mad_client and cm_client init Shifeng Li
2024-01-02  8:58 ` Leon Romanovsky
2024-01-02 11:33   ` Shifeng Li
2024-01-02 11:58     ` Leon Romanovsky
2024-01-02 12:30       ` Shifeng Li
2024-01-03 18:48 ` Jason Gunthorpe
     [not found]   ` <80cac9fd-7fed-403e-8889-78e2fc7a49b0@sangfor.com.cn>
2024-01-04 12:37     ` Jason Gunthorpe
2024-01-05  8:15       ` Shifeng Li
2024-01-05 14:19         ` Jason Gunthorpe
2024-01-15  3:27           ` Shifeng Li
2024-01-06  2:12       ` Ding Hui
2024-01-15 13:47         ` Jason Gunthorpe
     [not found]           ` <354e2bf7-a8b4-629d-3d2d-35951a52e8bd@sangfor.com.cn>
2024-01-26  2:25             ` Shifeng Li
2024-02-01  0:04               ` Jason Gunthorpe [this message]

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