From: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
To: Jens Axboe <axboe-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
Cc: "Alex Williamson"
<alex.williamson-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org,
linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-pci-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
"Jérôme Glisse" <jglisse-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
"Jason Gunthorpe" <jgg-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>,
"Christian König" <christian.koenig-5C7GfCeVMHo@public.gmane.org>,
"Benjamin Herrenschmidt"
<benh-XVmvHMARGAS8U2dJNN8I7kB+6BGkLq7r@public.gmane.org>,
"Bjorn Helgaas"
<bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>,
"Max Gurtovoy" <maxg-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>,
"Christoph Hellwig" <hch-jcswGhMUV9g@public.gmane.org>
Subject: Re: [PATCH v5 07/13] block: Add PCI P2P flag for request queue and check support for requests
Date: Wed, 5 Sep 2018 22:11:52 +0200 [thread overview]
Message-ID: <20180905201152.GA1893@lst.de> (raw)
In-Reply-To: <bcc1b3cf-2fd9-fa61-9cfb-b0e4d84e5d94-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
On Wed, Sep 05, 2018 at 01:54:31PM -0600, Jens Axboe wrote:
> On 9/5/18 1:56 PM, Christoph Hellwig wrote:
> > On Wed, Sep 05, 2018 at 01:45:04PM -0600, Jens Axboe wrote:
> >> The point is that the caller doesn't necessarily know where the bio
> >> will end up, hence the caller can't fully check if the whole stack
> >> supports P2P.
> >
> > The caller must necessarily know where the bio will end up, as for P2P
> > support we need to query if the bio target is P2P capable vs the
> > source of the P2P memory.
>
> Then what's the point of having the check at all?
Just an additional little safe guard. If you think it isn't worth
it I guess we can just drop it for now.
next prev parent reply other threads:[~2018-09-05 20:11 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-30 18:53 [PATCH v5 00/13] Copy Offload in NVMe Fabrics with P2P PCI Memory Logan Gunthorpe
2018-08-30 18:53 ` [PATCH v5 03/13] PCI/P2PDMA: Add PCI p2pmem DMA mappings to adjust the bus offset Logan Gunthorpe
[not found] ` <20180830185352.3369-1-logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2018-08-30 18:53 ` [PATCH v5 01/13] PCI/P2PDMA: Support peer-to-peer memory Logan Gunthorpe
[not found] ` <20180830185352.3369-2-logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2018-08-31 8:04 ` Christian König
[not found] ` <2711b3a7-f582-0dda-8ac2-530be7bda1bb-5C7GfCeVMHo@public.gmane.org>
2018-08-31 15:48 ` Logan Gunthorpe
2018-09-01 8:27 ` Christoph Hellwig
2018-08-31 16:19 ` Jonathan Cameron
[not found] ` <20180831171906.00002751-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2018-08-31 16:26 ` Logan Gunthorpe
2018-08-30 18:53 ` [PATCH v5 02/13] PCI/P2PDMA: Add sysfs group to display p2pmem stats Logan Gunthorpe
2018-08-30 18:53 ` [PATCH v5 04/13] PCI/P2PDMA: Introduce configfs/sysfs enable attribute helpers Logan Gunthorpe
2018-08-30 18:53 ` [PATCH v5 05/13] docs-rst: Add a new directory for PCI documentation Logan Gunthorpe
2018-08-30 18:53 ` [PATCH v5 06/13] PCI/P2PDMA: Add P2P DMA driver writer's documentation Logan Gunthorpe
2018-08-31 0:34 ` Randy Dunlap
[not found] ` <382af881-0ae1-0274-4628-0137071125b1-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
2018-08-31 15:44 ` Logan Gunthorpe
[not found] ` <20180830185352.3369-7-logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2018-08-31 8:08 ` Christian König
[not found] ` <98bff500-4e4c-3a34-6762-16ef4b076d90-5C7GfCeVMHo@public.gmane.org>
2018-08-31 15:51 ` Logan Gunthorpe
[not found] ` <6820d451-9591-1979-00bf-60c65fc4f136-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2018-08-31 17:38 ` Christian König
[not found] ` <30411655-9b90-749e-857f-318dac7cccbf-5C7GfCeVMHo@public.gmane.org>
2018-08-31 19:11 ` Logan Gunthorpe
2018-08-30 18:53 ` [PATCH v5 07/13] block: Add PCI P2P flag for request queue and check support for requests Logan Gunthorpe
[not found] ` <20180830185352.3369-8-logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2018-08-30 19:11 ` Jens Axboe
[not found] ` <b5ab8fa3-34ac-3117-fa0d-5206c3939435-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2018-08-30 19:17 ` Logan Gunthorpe
[not found] ` <7c5b9d2c-d94e-582c-f1d7-0827dbb7df7c-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2018-08-30 19:19 ` Jens Axboe
2018-09-01 8:28 ` Christoph Hellwig
[not found] ` <20180901082812.GB670-jcswGhMUV9g@public.gmane.org>
2018-09-03 22:26 ` Logan Gunthorpe
[not found] ` <5f79c012-c6e1-56bb-62fd-0689181fb2c9-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2018-09-05 19:26 ` Jens Axboe
[not found] ` <59b28977-8f2a-6228-2050-03fae6bdbedd-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2018-09-05 19:33 ` Logan Gunthorpe
2018-09-05 19:45 ` Jens Axboe
2018-09-05 19:53 ` Logan Gunthorpe
[not found] ` <09258b9b-3aed-9890-b31a-bd70a133966c-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2018-09-05 19:56 ` Christoph Hellwig
2018-09-05 19:54 ` Jens Axboe
[not found] ` <bcc1b3cf-2fd9-fa61-9cfb-b0e4d84e5d94-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2018-09-05 20:11 ` Christoph Hellwig [this message]
[not found] ` <20180905201152.GA1893-jcswGhMUV9g@public.gmane.org>
2018-09-05 20:09 ` Logan Gunthorpe
2018-09-05 20:14 ` Jens Axboe
[not found] ` <2a3394bd-5f13-4818-43f4-dfc61f501e05-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2018-09-05 20:18 ` Logan Gunthorpe
[not found] ` <e3ef26e6-6c8d-25b8-fa64-14594a51263c-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2018-09-05 20:19 ` Jens Axboe
[not found] ` <3af4d1d4-da07-c0a6-8464-9ddc1378f2f4-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2018-09-05 20:32 ` Logan Gunthorpe
[not found] ` <f9e660cd-b597-bb6e-56a2-82fe71cb3649-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2018-09-05 20:36 ` Jens Axboe
[not found] ` <34d9b2f7-9e6d-4a0a-77e5-ec0e99610f5c-tSWWG44O7X1aa/9Udqfwiw@public.gmane.org>
2018-09-05 21:03 ` Logan Gunthorpe
[not found] ` <c41c802c-9235-5383-2dfa-af9c1553f11b-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2018-09-05 21:13 ` Christoph Hellwig
2018-09-05 21:18 ` Jens Axboe
2018-09-10 16:41 ` Christoph Hellwig
[not found] ` <20180910164144.GA24591-jcswGhMUV9g@public.gmane.org>
2018-09-10 18:11 ` Logan Gunthorpe
2018-09-11 7:10 ` Christoph Hellwig
2018-08-30 18:53 ` [PATCH v5 08/13] IB/core: Ensure we map P2P memory correctly in rdma_rw_ctx_[init|destroy]() Logan Gunthorpe
[not found] ` <20180830185352.3369-9-logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2018-08-31 0:18 ` Sagi Grimberg
2018-08-30 18:53 ` [PATCH v5 09/13] nvme-pci: Use PCI p2pmem subsystem to manage the CMB Logan Gunthorpe
2018-08-30 18:53 ` [PATCH v5 10/13] nvme-pci: Add support for P2P memory in requests Logan Gunthorpe
2018-09-04 15:16 ` Jason Gunthorpe
[not found] ` <20180904151638.GL335-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
2018-09-04 15:47 ` Logan Gunthorpe
2018-09-05 19:22 ` Christoph Hellwig
2018-08-30 18:53 ` [PATCH v5 13/13] nvmet: Optionally use PCI P2P memory Logan Gunthorpe
[not found] ` <20180830185352.3369-14-logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2018-08-31 0:25 ` Sagi Grimberg
[not found] ` <ecbb669a-2e84-1333-7e0d-1560cf014750-NQWnxTmZq1alnMjI0IkVqw@public.gmane.org>
2018-08-31 15:41 ` Logan Gunthorpe
2018-08-30 19:20 ` [PATCH v5 00/13] Copy Offload in NVMe Fabrics with P2P PCI Memory Jerome Glisse
[not found] ` <20180830192012.GG3529-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2018-08-30 19:30 ` Logan Gunthorpe
2018-08-30 18:53 ` [PATCH v5 11/13] nvme-pci: Add a quirk for a pseudo CMB Logan Gunthorpe
2018-08-30 18:53 ` [PATCH v5 12/13] nvmet: Introduce helper functions to allocate and free request SGLs Logan Gunthorpe
[not found] ` <20180830185352.3369-13-logang-OTvnGxWRz7hWk0Htik3J/w@public.gmane.org>
2018-08-31 0:14 ` Sagi Grimberg
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