linux-pci.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Marc Zyngier <maz@kernel.org>
To: Laurent Vivier <lvivier@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
	linux-kernel@vger.kernel.org, linux-block@vger.kernel.org,
	Paul Mackerras <paulus@samba.org>,
	linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	"Michael S . Tsirkin" <mst@redhat.com>,
	Greg Kurz <groug@kaod.org>, Christoph Hellwig <hch@lst.de>,
	Michael Ellerman <mpe@ellerman.id.au>
Subject: Re: [PATCH v2 1/2] genirq: add an irq_create_mapping_affinity() function
Date: Wed, 25 Nov 2020 14:54:21 +0000	[thread overview]
Message-ID: <5100171ff6d4c3efffe008e1e0bf3707@kernel.org> (raw)
In-Reply-To: <e32641f7-0993-8923-7d74-5ac57a60f10d@redhat.com>

On 2020-11-25 14:09, Laurent Vivier wrote:
> On 25/11/2020 14:20, Thomas Gleixner wrote:
>> Laurent,
>> 
>> On Wed, Nov 25 2020 at 12:16, Laurent Vivier wrote:
>> 
>> The proper subsystem prefix is: 'genirq/irqdomain:' and the first 
>> letter
>> after the colon wants to be uppercase.
> 
> Ok.
> 
>>> This function adds an affinity parameter to irq_create_mapping().
>>> This parameter is needed to pass it to irq_domain_alloc_descs().
>> 
>> A changelog has to explain the WHY. 'The parameter is needed' is not
>> really useful information.
>> 
> 
> The reason of this change is explained in PATCH 2.
> 
> I have two patches, one to change the interface with no functional
> change (PATCH 1) and
> one to fix the problem (PATCH 2). Moreover they don't cover the same 
> subsystems.
> 
> I can either:
> - merge the two patches
> - or make a reference in the changelog of PATCH 1 to PATCH 2
>   (something like "(see folowing patch "powerpc/pseries: pass MSI 
> affinity to
>    irq_create_mapping()")")
> - or copy some information from PATCH 2
>   (something like "this parameter is needed by rtas_setup_msi_irqs()
> to pass the affinity
>    to irq_domain_alloc_descs() to fix multiqueue affinity")
> 
> What do you prefer?

How about something like this for the first patch:

"There is currently no way to convey the affinity of an interrupt
  via irq_create_mapping(), which creates issues for devices that
  expect that affinity to be managed by the kernel.

  In order to sort this out, rename irq_create_mapping() to
  irq_create_mapping_affinity() with an additional affinity parameter
  that can conveniently passed down to irq_domain_alloc_descs().

  irq_create_mapping() is then re-implemented as a wrapper around
  irq_create_mapping_affinity()."

Thanks,

         M.
-- 
Jazz is not dead. It just smells funny...

  reply	other threads:[~2020-11-25 14:54 UTC|newest]

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-25 11:16 [PATCH v2 0/2] powerpc/pseries: fix MSI/X IRQ affinity on pseries Laurent Vivier
2020-11-25 11:16 ` [PATCH v2 1/2] genirq: add an irq_create_mapping_affinity() function Laurent Vivier
2020-11-25 12:45   ` Greg Kurz
2020-11-25 13:20   ` Thomas Gleixner
2020-11-25 14:09     ` Laurent Vivier
2020-11-25 14:54       ` Marc Zyngier [this message]
2020-11-25 15:00         ` Laurent Vivier
2020-11-25 11:16 ` [PATCH v2 2/2] powerpc/pseries: pass MSI affinity to irq_create_mapping() Laurent Vivier
2020-11-25 12:51   ` Greg Kurz

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=5100171ff6d4c3efffe008e1e0bf3707@kernel.org \
    --to=maz@kernel.org \
    --cc=benh@kernel.crashing.org \
    --cc=groug@kaod.org \
    --cc=hch@lst.de \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pci@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=lvivier@redhat.com \
    --cc=mpe@ellerman.id.au \
    --cc=mst@redhat.com \
    --cc=paulus@samba.org \
    --cc=tglx@linutronix.de \
    --subject='Re: [PATCH v2 1/2] genirq: add an irq_create_mapping_affinity() function' \
    /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

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).