All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Roger Pau Monné" <roger.pau@citrix.com>
To: Matthew Barnes <matthew.barnes@cloud.com>
Cc: xen-devel@lists.xenproject.org,
	Oleksii Kurochko <oleksii.kurochko@gmail.com>,
	Community Manager <community.manager@xenproject.org>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	Jan Beulich <jbeulich@suse.com>, Julien Grall <julien@xen.org>,
	Stefano Stabellini <sstabellini@kernel.org>
Subject: Re: [PATCH] x86/APIC: Remove x2APIC pure cluster mode
Date: Tue, 24 Sep 2024 17:10:00 +0200	[thread overview]
Message-ID: <ZvLWSEwbdL1kpvC6@macbook.local> (raw)
In-Reply-To: <e43028a51f8cea02421d0856376faada8ab186d4.1726840133.git.matthew.barnes@cloud.com>

On Mon, Sep 23, 2024 at 03:35:59PM +0100, Matthew Barnes wrote:
> With the introduction of mixed x2APIC mode (using cluster addressing for
> IPIs and physical for external interrupts) the use of pure cluster mode
> doesn't have any benefit.
> 
> Remove the mode itself, leaving only the code required for logical
> addressing when sending IPIs.
> 
> Implements: https://gitlab.com/xen-project/xen/-/issues/189

There's at least one extra bit which I would also like to see removed,
either in this patch, or as following patch.

In struct arch_irq_desc we have 3 cpumasks: cpu_mask, old_cpu_mask and
pending_mask.  After dropping cluster mode for external interrupts,
those fields could become integers AFACT, as now interrupts can only
target a single CPU opposed to a logical CPU set.

Thanks, Roger.


  parent reply	other threads:[~2024-09-24 15:10 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-23 14:35 [PATCH] x86/APIC: Remove x2APIC pure cluster mode Matthew Barnes
2024-09-24 14:51 ` Jan Beulich
2024-09-24 15:00 ` oleksii.kurochko
2024-09-24 15:10 ` Roger Pau Monné [this message]
2024-09-24 15:27   ` Andrew Cooper
2024-09-24 16:14     ` Roger Pau Monné
2024-09-24 16:21       ` Jan Beulich
2024-09-24 17:10         ` Roger Pau Monné
2024-09-24 18:20           ` Andrew Cooper
2024-09-25  7:59             ` Roger Pau Monné
2024-09-24 15:27   ` Jan Beulich
2024-09-24 15:30 ` Andrew Cooper

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=ZvLWSEwbdL1kpvC6@macbook.local \
    --to=roger.pau@citrix.com \
    --cc=andrew.cooper3@citrix.com \
    --cc=community.manager@xenproject.org \
    --cc=jbeulich@suse.com \
    --cc=julien@xen.org \
    --cc=matthew.barnes@cloud.com \
    --cc=oleksii.kurochko@gmail.com \
    --cc=sstabellini@kernel.org \
    --cc=xen-devel@lists.xenproject.org \
    /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.