From: Peter Zijlstra <peterz@infradead.org>
To: Joel Fernandes <joelagnelf@nvidia.com>
Cc: "Boqun Feng" <boqun@kernel.org>, "Lyude Paul" <lyude@redhat.com>,
rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
"Thomas Gleixner" <tglx@linutronix.de>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Daniel Almeida" <daniel.almeida@collabora.com>,
"Miguel Ojeda" <ojeda@kernel.org>,
"Alex Gaynor" <alex.gaynor@gmail.com>,
"Gary Guo" <gary@garyguo.net>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
"Benno Lossin" <lossin@kernel.org>,
"Andreas Hindborg" <a.hindborg@kernel.org>,
"Alice Ryhl" <aliceryhl@google.com>,
"Trevor Gross" <tmgross@umich.edu>,
"Danilo Krummrich" <dakr@kernel.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Ingo Molnar" <mingo@redhat.com>, "Will Deacon" <will@kernel.org>,
"Waiman Long" <longman@redhat.com>
Subject: Re: [PATCH v17 02/16] preempt: Track NMI nesting to separate per-CPU counter
Date: Fri, 6 Feb 2026 09:42:58 +0100 [thread overview]
Message-ID: <20260206084258.GO1282955@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <52c1f833-0967-4692-8275-6d448a104350@nvidia.com>
On Thu, Feb 05, 2026 at 08:24:40PM -0500, Joel Fernandes wrote:
> > I guess Peter was trying to say it's not a slow path if you consider
> > perf event interrupts on x86? [1]
>
> How are we handling this performance issue then on 32-bit x86 architecture with
> perf? Or are we saying we don't care about performance on 32-bit?
Yeah, in general I don't consider any 32bit architecture performance
critical at this point. Its pure legacy code, to be removed at some
point.
To x86_32 in particular, we make it limp along. It sorta builds and
sorta boots but meh. It doesn't even have most of the speculation fixes.
You really, as in *REALLY* should not be running a x86_32 kernel.
I mean, if you still want to run Linux on your museum grade Pentium-II
processor, don't let me stop you. Just don't expect miracles.
next prev parent reply other threads:[~2026-02-06 8:43 UTC|newest]
Thread overview: 47+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-21 22:39 [PATCH v17 00/16] Refcounted interrupts, SpinLockIrq for rust Lyude Paul
2026-01-21 22:39 ` [PATCH v17 01/16] preempt: Introduce HARDIRQ_DISABLE_BITS Lyude Paul
2026-01-21 22:39 ` [PATCH v17 02/16] preempt: Track NMI nesting to separate per-CPU counter Lyude Paul
2026-02-03 11:44 ` Peter Zijlstra
2026-02-06 1:22 ` Joel Fernandes
2026-02-03 12:15 ` Peter Zijlstra
2026-02-04 11:12 ` Peter Zijlstra
2026-02-04 12:32 ` Gary Guo
2026-02-04 13:00 ` Peter Zijlstra
2026-02-05 21:40 ` Boqun Feng
2026-02-05 22:17 ` Joel Fernandes
2026-02-06 0:50 ` Joel Fernandes
2026-02-06 1:14 ` Boqun Feng
2026-02-06 1:24 ` Joel Fernandes
2026-02-06 2:51 ` Boqun Feng
2026-02-06 8:13 ` Joel Fernandes
2026-02-06 15:28 ` Boqun Feng
2026-02-06 16:00 ` Joel Fernandes
2026-02-06 16:16 ` Boqun Feng
2026-02-07 22:11 ` Joel Fernandes
2026-02-06 8:42 ` Peter Zijlstra [this message]
2026-02-05 22:07 ` Boqun Feng
2026-02-06 8:45 ` Peter Zijlstra
2026-01-21 22:39 ` [PATCH v17 03/16] preempt: Introduce __preempt_count_{sub, add}_return() Lyude Paul
2026-01-21 22:39 ` [PATCH v17 04/16] openrisc: Include <linux/cpumask.h> in smp.h Lyude Paul
2026-01-21 22:39 ` [PATCH v17 05/16] irq & spin_lock: Add counted interrupt disabling/enabling Lyude Paul
2026-01-21 22:39 ` [PATCH v17 06/16] irq: Add KUnit test for refcounted interrupt enable/disable Lyude Paul
2026-01-30 7:43 ` David Gow
2026-01-21 22:39 ` [PATCH v17 07/16] rust: Introduce interrupt module Lyude Paul
2026-01-21 22:39 ` [PATCH v17 08/16] rust: helper: Add spin_{un,}lock_irq_{enable,disable}() helpers Lyude Paul
2026-01-26 13:25 ` Gary Guo
2026-01-21 22:39 ` [PATCH v17 09/16] rust: sync: Add SpinLockIrq Lyude Paul
2026-01-23 22:26 ` Benno Lossin
2026-01-21 22:39 ` [PATCH v17 10/16] rust: sync: Introduce lock::Lock::lock_with() and friends Lyude Paul
2026-01-22 11:56 ` kernel test robot
2026-01-23 22:55 ` Benno Lossin
2026-01-26 13:31 ` Gary Guo
2026-01-21 22:39 ` [PATCH v17 11/16] rust: sync: Expose lock::Backend Lyude Paul
2026-01-23 22:56 ` Benno Lossin
2026-01-21 22:39 ` [PATCH v17 12/16] rust: sync: lock/global: Rename B to G in trait bounds Lyude Paul
2026-01-21 22:39 ` [PATCH v17 13/16] rust: sync: Add a lifetime parameter to lock::global::GlobalGuard Lyude Paul
2026-01-21 22:39 ` [PATCH v17 14/16] rust: sync: lock/global: Add Backend parameter to GlobalGuard Lyude Paul
2026-01-21 22:39 ` [PATCH v17 15/16] rust: sync: lock/global: Add ContextualBackend support to GlobalLock Lyude Paul
2026-01-21 22:39 ` [PATCH v17 16/16] locking: Switch to _irq_{disable,enable}() variants in cleanup guards Lyude Paul
2026-01-26 13:24 ` [PATCH v17 00/16] Refcounted interrupts, SpinLockIrq for rust Gary Guo
2026-01-26 16:17 ` Boqun Feng
2026-02-03 0:36 ` Boqun Feng
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=20260206084258.GO1282955@noisy.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=a.hindborg@kernel.org \
--cc=akpm@linux-foundation.org \
--cc=alex.gaynor@gmail.com \
--cc=aliceryhl@google.com \
--cc=bjorn3_gh@protonmail.com \
--cc=boqun.feng@gmail.com \
--cc=boqun@kernel.org \
--cc=dakr@kernel.org \
--cc=daniel.almeida@collabora.com \
--cc=gary@garyguo.net \
--cc=joelagnelf@nvidia.com \
--cc=linux-kernel@vger.kernel.org \
--cc=longman@redhat.com \
--cc=lossin@kernel.org \
--cc=lyude@redhat.com \
--cc=mingo@redhat.com \
--cc=ojeda@kernel.org \
--cc=rust-for-linux@vger.kernel.org \
--cc=tglx@linutronix.de \
--cc=tmgross@umich.edu \
--cc=will@kernel.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox