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From: Jason Gunthorpe <jgg@ziepe.ca>
To: Yanjun Zhu <yanjun.zhu@linux.dev>
Cc: leon@kernel.org, linux-rdma@vger.kernel.org,
	Yi Zhang <yi.zhang@redhat.com>
Subject: Re: [PATCHv3 1/1] RDMA/rxe: Fix a dead lock problem
Date: Thu, 14 Apr 2022 13:18:46 -0300	[thread overview]
Message-ID: <20220414161846.GM64706@ziepe.ca> (raw)
In-Reply-To: <75363d6a-99f2-f61a-0f41-87e641746efa@linux.dev>

On Thu, Apr 14, 2022 at 11:13:57PM +0800, Yanjun Zhu wrote:
> 在 2022/4/14 21:52, Jason Gunthorpe 写道:
> > On Thu, Apr 14, 2022 at 09:01:29PM +0800, Yanjun Zhu wrote:
> > 
> > > > > Still no, this does almost every allocation - only AH with the
> > > > > non-blocking flag set should use this path.
> > 
> > > To the function ib_send_cm_req, the call chain is as below.
> > > 
> > > ib_send_cm_req --> cm_alloc_priv_msg --> cm_alloc_msg --> rdma_create_ah -->
> > > _rdma_create_ah --> rxe_create_ah --> rxe_av_chk_attr -->__rxe_add_to_pool
> > > 
> > > As such, xa_lock_irqsave/irqrestore is selected.
> > 
> > As I keep saying, only the rxe_create_ah() with the non-blocking flag
> > set should use the GFP_ATOMIC. All other paths must use GFP_KERNEL.
> > 
> 
> Got it. The GFP_ATOMIC/GFP_KERNEL are used in different paths.
> rxe_create_ah will use GFP_ATOMIC and others will use GFP_KERNEL.
> So the codes should be as below:

This seems better

Jason

  parent reply	other threads:[~2022-04-14 16:48 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-04-13  7:42 [PATCHv3 1/1] RDMA/rxe: Fix a dead lock problem yanjun.zhu
2022-04-13  0:45 ` Jason Gunthorpe
2022-04-13 14:50   ` Yanjun Zhu
2022-04-14 13:01     ` Yanjun Zhu
2022-04-14 13:52       ` Jason Gunthorpe
2022-04-14 15:13         ` Yanjun Zhu
2022-04-14 16:12           ` Leon Romanovsky
2022-04-15  2:35             ` Yanjun Zhu
2022-04-14 16:18           ` Jason Gunthorpe [this message]
2022-04-15  2:36             ` Yanjun Zhu

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