From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: "Thomas Gleixner" <tglx@kernel.org>,
"Ingo Molnar" <mingo@redhat.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Paul Walmsley" <pjw@kernel.org>,
"Palmer Dabbelt" <palmer@dabbelt.com>,
"Albert Ou" <aou@eecs.berkeley.edu>,
"Borislav Petkov" <bp@alien8.de>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
x86@kernel.org, "Catalin Marinas" <catalin.marinas@arm.com>,
"Will Deacon" <will@kernel.org>,
"Heiko Carstens" <hca@linux.ibm.com>,
"Vasily Gorbik" <gor@linux.ibm.com>,
"Alexander Gordeev" <agordeev@linux.ibm.com>,
"Arnd Bergmann" <arnd@arndb.de>,
"Darren Hart" <dvhart@infradead.org>,
"Davidlohr Bueso" <dave@stgolabs.net>,
"André Almeida" <andrealmeid@igalia.com>,
linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org,
linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org,
"Alexandre Ghiti" <alex@ghiti.fr>,
"H. Peter Anvin" <hpa@zytor.com>,
"Kiryl Shutsemau" <kas@kernel.org>,
"Sean Christopherson" <seanjc@google.com>,
"Charlie Jenkins" <charlie@rivosinc.com>,
"Charles Mirabile" <cmirabil@redhat.com>,
"Christian Borntraeger" <borntraeger@linux.ibm.com>,
"Sven Schnelle" <svens@linux.ibm.com>,
"Thomas Huth" <thuth@redhat.com>,
"Jisheng Zhang" <jszhang@kernel.org>
Subject: Re: [RFC PATCH v2 7/7] futex: Use runtime constants for __futex_hash() hot path
Date: Mon, 16 Mar 2026 09:14:29 +0100 [thread overview]
Message-ID: <20260316081429.FJx4fnNl@linutronix.de> (raw)
In-Reply-To: <20260316052401.18910-8-kprateek.nayak@amd.com>
On 2026-03-16 05:24:01 [+0000], K Prateek Nayak wrote:
> From: Peter Zijlstra <peterz@infradead.org>
>
> Runtime constify the read-only after init data __futex_shift(shift_32),
> __futex_mask(mask_32), and __futex_queues(ptr) used in __futex_hash()
> hot path to avoid referencing global variable.
>
> This also allows __futex_queues to be allocated dynamically to
> "nr_node_ids" slots instead of reserving config dependent MAX_NUMNODES
> (1 << CONFIG_NODES_SHIFT) worth of slots upfront.
>
> No functional chages intended.
>
> [ prateek: Dynamically allocate __futex_queues, mark the global data
> __ro_after_init since they are constified after futex_init(). ]
>
> Link: https://patch.msgid.link/20260227161841.GH606826@noisy.programming.kicks-ass.net
> Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> # MAX_NUMNODES bloat
> Not-yet-signed-off-by: Peter Zijlstra <peterz@infradead.org>
> Signed-off-by: K Prateek Nayak <kprateek.nayak@amd.com>
This all looks nice. Let me look later at the resulting code. Thank you
so far ;)
Sebastian
_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv
next prev parent reply other threads:[~2026-03-16 8:14 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-16 5:23 [RFC PATCH v2 0/7] futex: Use runtime constants for futex_hash computation K Prateek Nayak
2026-03-16 5:23 ` [RFC PATCH v2 1/7] x86/runtime-const: Introduce runtime_const_mask_32() K Prateek Nayak
2026-03-16 5:23 ` [RFC PATCH v2 2/7] arm64/runtime-const: " K Prateek Nayak
2026-03-16 11:50 ` David Laight
2026-03-16 17:09 ` K Prateek Nayak
2026-03-16 5:23 ` [RFC PATCH v2 3/7] arm64/runtime-const: Use aarch64_insn_patch_text_nosync() for patching K Prateek Nayak
2026-03-16 11:52 ` David Laight
2026-03-16 17:13 ` K Prateek Nayak
2026-03-16 5:23 ` [RFC PATCH v2 4/7] riscv/runtime-const: Introduce runtime_const_mask_32() K Prateek Nayak
2026-03-16 5:23 ` [RFC PATCH v2 5/7] s390/runtime-const: " K Prateek Nayak
2026-03-16 19:19 ` Heiko Carstens
2026-03-17 1:55 ` K Prateek Nayak
2026-03-16 5:24 ` [RFC PATCH v2 6/7] asm-generic/runtime-const: Add dummy runtime_const_mask_32() K Prateek Nayak
2026-03-16 5:24 ` [RFC PATCH v2 7/7] futex: Use runtime constants for __futex_hash() hot path K Prateek Nayak
2026-03-16 8:14 ` Sebastian Andrzej Siewior [this message]
2026-03-16 17:15 ` K Prateek Nayak
2026-03-17 3:06 ` Samuel Holland
2026-03-17 5:11 ` K Prateek Nayak
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=20260316081429.FJx4fnNl@linutronix.de \
--to=bigeasy@linutronix.de \
--cc=agordeev@linux.ibm.com \
--cc=alex@ghiti.fr \
--cc=andrealmeid@igalia.com \
--cc=aou@eecs.berkeley.edu \
--cc=arnd@arndb.de \
--cc=borntraeger@linux.ibm.com \
--cc=bp@alien8.de \
--cc=catalin.marinas@arm.com \
--cc=charlie@rivosinc.com \
--cc=cmirabil@redhat.com \
--cc=dave.hansen@linux.intel.com \
--cc=dave@stgolabs.net \
--cc=dvhart@infradead.org \
--cc=gor@linux.ibm.com \
--cc=hca@linux.ibm.com \
--cc=hpa@zytor.com \
--cc=jszhang@kernel.org \
--cc=kas@kernel.org \
--cc=kprateek.nayak@amd.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-riscv@lists.infradead.org \
--cc=linux-s390@vger.kernel.org \
--cc=mingo@redhat.com \
--cc=palmer@dabbelt.com \
--cc=peterz@infradead.org \
--cc=pjw@kernel.org \
--cc=seanjc@google.com \
--cc=svens@linux.ibm.com \
--cc=tglx@kernel.org \
--cc=thuth@redhat.com \
--cc=will@kernel.org \
--cc=x86@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