From: Thomas Gleixner <tglx@kernel.org>
To: Eric Dumazet <edumazet@google.com>, Luigi Rizzo <lrizzo@google.com>
Cc: maz@kernel.org, rizzo.unipi@gmail.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] genirq: move clear of kstat_irqs to free_desc()
Date: Tue, 13 Jan 2026 10:09:42 +0100 [thread overview]
Message-ID: <874iopg9pl.ffs@tglx> (raw)
In-Reply-To: <CANn89iKQyGhx+jbP5pNSqTU4dsweH-1r9LEkdG6CHDUaicS0nA@mail.gmail.com>
On Mon, Jan 12 2026 at 21:18, Eric Dumazet wrote:
>> - scoped_guard(raw_spinlock_irqsave, &desc->lock)
>> + scoped_guard(raw_spinlock_irqsave, &desc->lock) {
>> desc_set_defaults(irq, desc, irq_desc_get_node(desc), NULL, NULL);
>> + for_each_possible_cpu(cpu)
>> + *per_cpu_ptr(desc->kstat_irqs, cpu) = (struct irqstat) { };
>> + }
>
>
> It seems that for_each_possible_cpu(cpu) could be done outside of the
> desc->lock protection.
>
> This would shorten hard-irq blocking by N cache line misses.
Right, though it really does not matter unless you deeply care about:
alpha, arc, hexagon, m68k, mips, parisc, sparc, xtensa and random old
ARM32 platforms :)
next prev parent reply other threads:[~2026-01-13 9:09 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-12 8:32 [PATCH v2] genirq: move clear of kstat_irqs to free_desc() Luigi Rizzo
2026-01-12 20:18 ` Eric Dumazet
2026-01-13 9:09 ` Thomas Gleixner [this message]
[not found] ` <CAMOZA0Ld81_W9tECpgM_Z3iH5v_Gvh5ngT6HiTp7SR=pvAJryw@mail.gmail.com>
2026-01-13 9:31 ` Thomas Gleixner
2026-01-13 9:17 ` [tip: irq/core] genirq: Move " tip-bot2 for Luigi Rizzo
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=874iopg9pl.ffs@tglx \
--to=tglx@kernel.org \
--cc=edumazet@google.com \
--cc=linux-kernel@vger.kernel.org \
--cc=lrizzo@google.com \
--cc=maz@kernel.org \
--cc=rizzo.unipi@gmail.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