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From: Jason Gunthorpe <jgg@ziepe.ca>
To: Weihang Li <liweihang@huawei.com>
Cc: dledford@redhat.com, leon@kernel.org, linux-rdma@vger.kernel.org,
	linuxarm@huawei.com
Subject: Re: [PATCH for-next] RDMA/hns: Add support for extended atomic in userspace
Date: Thu, 23 Jan 2020 18:54:47 -0400	[thread overview]
Message-ID: <20200123225447.GA15167@ziepe.ca> (raw)
In-Reply-To: <cebc88dc-09fe-a1dd-a3da-a3de55deb732@huawei.com>

On Wed, Jan 22, 2020 at 04:54:55PM +0800, Weihang Li wrote:
> 
> 
> On 2020/1/17 3:51, Jason Gunthorpe wrote:
> >>> What happens to your userspace if it runs on an old kernel and tries
> >>> to use extended atomic?
> >>>
> >>> Jason
> >>>
> >> Hi Jason,
> >>
> >> If the hns userspace runs with old kernel, the hardware will report a asynchronous
> >> event for the extended atomic operation and modify the qp to error state because
> >> the enable bit in this qp's context hasn't been set.
> >>
> >> The driver will print like this:
> >>
> >> [ 1252.240921] hns3 0000:7d:00.0: Invalid request local work queue 0x9 error.
> >> [ 1252.247772] hns3 0000:7d:00.0: no hr_qp can be found!
> > Ideally the provider will not set
> > IBV_PCI_ATOMIC_OPERATION_4_BYTE_SIZE_SUP and related without kernel
> > support..
> > 
> > I've applied this patch, but I feel like you may need a followup to
> > fix the capability reporting?
> > 
> > Jason
> 
> Hi Jason,
> 
> Thank for your suggestions.
> 
> But I'm confuse about the relationship between "PCI ATOMIC" in this macro
> and atomic operations in RDMA.
> 
> I found the related series on patchwork:
> https://patchwork.kernel.org/cover/10782873/

I may have got the wrong capability bit here, I'm not sure where the
capability bits for extended atomics are actually

Jason

  parent reply	other threads:[~2020-01-23 22:54 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-01-15  1:42 [PATCH for-next] RDMA/hns: Add support for extended atomic in userspace Weihang Li
2020-01-15 20:56 ` Jason Gunthorpe
2020-01-16  4:05   ` Weihang Li
2020-01-16 19:51     ` Jason Gunthorpe
2020-01-22  8:54       ` Weihang Li
2020-01-22 14:08         ` Tom Talpey
2020-01-26  3:38           ` Weihang Li
2020-01-23 22:54         ` Jason Gunthorpe [this message]
2020-01-26  3:42           ` Weihang Li

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