From: Simon Horman <horms@kernel.org>
To: Mohammad Heib <mheib@redhat.com>
Cc: netdev@vger.kernel.org, oss-drivers@corigine.com,
louis.peens@corigine.com
Subject: Re: [PATCH net] nfp: use irq_update_affinity_hint()
Date: Sun, 10 Nov 2024 13:31:28 +0000 [thread overview]
Message-ID: <20241110133128.GM4507@kernel.org> (raw)
In-Reply-To: <20241107115002.413358-1-mheib@redhat.com>
On Thu, Nov 07, 2024 at 01:50:02PM +0200, Mohammad Heib wrote:
> irq_set_affinity_hint() is deprecated, Use irq_update_affinity_hint()
> instead. This removes the side-effect of actually applying the affinity.
>
> The driver does not really need to worry about spreading its IRQs across
> CPUs. The core code already takes care of that. when the driver applies the
> affinities by itself, it breaks the users' expectations:
>
> 1. The user configures irqbalance with IRQBALANCE_BANNED_CPULIST in
> order to prevent IRQs from being moved to certain CPUs that run a
> real-time workload.
>
> 2. nfp device reopening will resets the affinity
> in nfp_net_netdev_open().
>
> 3. nfp has no idea about irqbalance's config, so it may move an IRQ to
> a banned CPU. The real-time workload suffers unacceptable latency.
>
> Signed-off-by: Mohammad Heib <mheib@redhat.com>
Reviewed-by: Simon Horman <horms@kernel.org>
next prev parent reply other threads:[~2024-11-10 13:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-11-07 11:50 [PATCH net] nfp: use irq_update_affinity_hint() Mohammad Heib
2024-11-10 13:31 ` Simon Horman [this message]
2024-11-11 5:33 ` Louis Peens
2024-11-12 0:10 ` patchwork-bot+netdevbpf
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=20241110133128.GM4507@kernel.org \
--to=horms@kernel.org \
--cc=louis.peens@corigine.com \
--cc=mheib@redhat.com \
--cc=netdev@vger.kernel.org \
--cc=oss-drivers@corigine.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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.