From: Logan Gunthorpe <logang@deltatee.com>
To: Christoph Hellwig <hch@lst.de>
Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org,
linux-nvme@lists.infradead.org, linux-rdma@vger.kernel.org,
Bjorn Helgaas <bhelgaas@google.com>,
Christian Koenig <Christian.Koenig@amd.com>,
Jason Gunthorpe <jgg@mellanox.com>,
Sagi Grimberg <sagi@grimberg.me>, Keith Busch <kbusch@kernel.org>,
Jens Axboe <axboe@fb.com>,
Dan Williams <dan.j.williams@intel.com>,
Eric Pilmore <epilmore@gigaio.com>,
Stephen Bates <sbates@raithlin.com>
Subject: Re: [PATCH v2 03/14] PCI/P2PDMA: Add constants for not-supported result upstream_bridge_distance()
Date: Thu, 8 Aug 2019 09:58:50 -0600 [thread overview]
Message-ID: <ae77f630-81dc-62e8-727c-add3578ca002@deltatee.com> (raw)
In-Reply-To: <20190808073109.GC29852@lst.de>
On 2019-08-08 1:31 a.m., Christoph Hellwig wrote:
> On Wed, Aug 07, 2019 at 09:58:06AM -0600, Logan Gunthorpe wrote:
>> We only calculate it at the same time as we calculate the distance. This
>> is necessary because, to calculate the type, we have to walk the tree
>> and check the ACS bits. If we separated it, we'd have to walk the tree
>> twice in a very similar way just to determine both the distance and the
>> mapping type.
>
> Calculating it together makes perfect sense. What I find odd is the
> overloading of a single return value. Why not return the map type as
> the return value, and the distance as a by reference argument to keep
> them properly separated?
Ok, understood. I'll make that change and send some incremental patches
to Bjorn tomorrow.
Logan
next prev parent reply other threads:[~2019-08-08 15:59 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-30 16:35 [PATCH v2 00/14] PCI/P2PDMA: Support transactions that hit the host bridge Logan Gunthorpe
2019-07-30 16:35 ` [PATCH v2 01/14] PCI/P2PDMA: Introduce private pagemap structure Logan Gunthorpe
2019-07-30 16:35 ` [PATCH v2 02/14] PCI/P2PDMA: Add the provider's pci_dev to the pci_p2pdma_pagemap struct Logan Gunthorpe
2019-07-30 16:35 ` [PATCH v2 03/14] PCI/P2PDMA: Add constants for not-supported result upstream_bridge_distance() Logan Gunthorpe
2019-08-07 5:54 ` Christoph Hellwig
2019-08-07 15:58 ` Logan Gunthorpe
2019-08-08 7:31 ` Christoph Hellwig
2019-08-08 15:58 ` Logan Gunthorpe [this message]
2019-07-30 16:35 ` [PATCH v2 04/14] PCI/P2PDMA: Factor out __upstream_bridge_distance() Logan Gunthorpe
2019-07-30 16:35 ` [PATCH v2 05/14] PCI/P2PDMA: Apply host bridge white list for ACS Logan Gunthorpe
2019-07-30 16:35 ` [PATCH v2 06/14] PCI/P2PDMA: Factor out host_bridge_whitelist() Logan Gunthorpe
2019-07-30 16:35 ` [PATCH v2 07/14] PCI/P2PDMA: Add whitelist support for Intel Host Bridges Logan Gunthorpe
2019-07-30 16:35 ` [PATCH v2 08/14] PCI/P2PDMA: Add attrs argument to pci_p2pdma_map_sg() Logan Gunthorpe
2019-07-30 16:35 ` [PATCH v2 09/14] PCI/P2PDMA: Introduce pci_p2pdma_unmap_sg() Logan Gunthorpe
2019-07-30 16:35 ` [PATCH v2 10/14] PCI/P2PDMA: Factor out __pci_p2pdma_map_sg() Logan Gunthorpe
2019-07-30 16:35 ` [PATCH v2 11/14] PCI/P2PDMA: Store mapping method in an xarray Logan Gunthorpe
2019-08-07 5:59 ` Christoph Hellwig
2019-07-30 16:35 ` [PATCH v2 12/14] PCI/P2PDMA: dma_map P2PDMA map requests that traverse the host bridge Logan Gunthorpe
2019-07-30 16:35 ` [PATCH v2 13/14] PCI/P2PDMA: No longer require no-mmu for host bridge whitelist Logan Gunthorpe
2019-08-07 5:59 ` Christoph Hellwig
2019-08-07 12:43 ` Bjorn Helgaas
2019-08-08 7:29 ` Christoph Hellwig
2019-07-30 16:35 ` [PATCH v2 14/14] PCI/P2PDMA: Update documentation for pci_p2pdma_distance_many() Logan Gunthorpe
2019-08-06 23:44 ` [PATCH v2 00/14] PCI/P2PDMA: Support transactions that hit the host bridge Bjorn Helgaas
2019-08-07 0:31 ` Logan Gunthorpe
2019-08-07 19:29 ` Bjorn Helgaas
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=ae77f630-81dc-62e8-727c-add3578ca002@deltatee.com \
--to=logang@deltatee.com \
--cc=Christian.Koenig@amd.com \
--cc=axboe@fb.com \
--cc=bhelgaas@google.com \
--cc=dan.j.williams@intel.com \
--cc=epilmore@gigaio.com \
--cc=hch@lst.de \
--cc=jgg@mellanox.com \
--cc=kbusch@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-nvme@lists.infradead.org \
--cc=linux-pci@vger.kernel.org \
--cc=linux-rdma@vger.kernel.org \
--cc=sagi@grimberg.me \
--cc=sbates@raithlin.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).