From: "Arnd Bergmann" <arnd@arndb.de>
To: "Peter Zijlstra" <peterz@infradead.org>,
"Linus Torvalds" <torvalds@linux-foundation.org>
Cc: "Jonathan Corbet" <corbet@lwn.net>,
"Will Deacon" <will@kernel.org>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Mark Rutland" <mark.rutland@arm.com>,
"Catalin Marinas" <catalin.marinas@arm.com>,
dennis@kernel.org, "Tejun Heo" <tj@kernel.org>,
"Christoph Lameter" <cl@linux.com>,
"Heiko Carstens" <hca@linux.ibm.com>,
gor@linux.ibm.com, "Alexander Gordeev" <agordeev@linux.ibm.com>,
borntraeger@linux.ibm.com, "Sven Schnelle" <svens@linux.ibm.com>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>,
"Dave Hansen" <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
"Joerg Roedel" <joro@8bytes.org>,
suravee.suthikulpanit@amd.com,
"Robin Murphy" <robin.murphy@arm.com>,
"David Woodhouse" <dwmw2@infradead.org>,
"Baolu Lu" <baolu.lu@linux.intel.com>,
"Herbert Xu" <herbert@gondor.apana.org.au>,
"David S . Miller" <davem@davemloft.net>,
"Pekka Enberg" <penberg@kernel.org>,
"David Rientjes" <rientjes@google.com>,
"Joonsoo Kim" <iamjoonsoo.kim@lge.com>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Vlastimil Babka" <vbabka@suse.cz>,
"Roman Gushchin" <roman.gushchin@linux.dev>,
"Hyeonggon Yoo" <42.hyeyoo@gmail.com>,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, linux-s390@vger.kernel.org,
iommu@lists.linux.dev, Linux-Arch <linux-arch@vger.kernel.org>,
linux-crypto@vger.kernel.org,
"Stephen Rothwell" <sfr@canb.auug.org.au>,
"Michael Ellerman" <mpe@ellerman.id.au>
Subject: Re: [PATCH v3 08/11] slub: Replace cmpxchg_double()
Date: Thu, 25 May 2023 12:52:06 +0200 [thread overview]
Message-ID: <292934ce-73fa-4077-9051-2ad909828f4a@app.fastmail.com> (raw)
In-Reply-To: <20230525102946.GE38236@hirez.programming.kicks-ass.net>
On Thu, May 25, 2023, at 12:29, Peter Zijlstra wrote:
> On Wed, May 24, 2023 at 11:32:47AM +0200, Peter Zijlstra wrote:
>> On Mon, May 15, 2023 at 09:57:07AM +0200, Peter Zijlstra wrote:
>
> This then also means I need to look at this_cpu_cmpxchg128 and
> this_cpu_cmoxchg64 behaviour when we dont have the CPUID feature.
>
> Because current verions seem to assume the instruction is present.
As far as I could tell when reviewing your series, this_cpu_cmpxchg64()
is always available on all architectures. Depending on compile-time
feature detection this would be either a native instruction that
is guaranteed to work, or the irq-disabled version. On x86, this
is handled at runtime with alternative_io().
this_cpu_cmpxchg128() clearly needed the system_has_cmpxchg128()
check, same as system_has_cmpxchg_double() today.
Arnd
next prev parent reply other threads:[~2023-05-25 10:52 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-05-15 7:56 [PATCH v3 00/11] Introduce cmpxchg128() -- aka. the demise of cmpxchg_double() Peter Zijlstra
2023-05-15 7:57 ` [PATCH v3 01/11] cyrpto/b128ops: Remove struct u128 Peter Zijlstra
2023-05-20 10:49 ` [tip: locking/core] " tip-bot2 for Peter Zijlstra
2023-05-22 10:27 ` tip-bot2 for Peter Zijlstra
2023-05-15 7:57 ` [PATCH v3 02/11] types: Introduce [us]128 Peter Zijlstra
2023-05-20 10:49 ` [tip: locking/core] " tip-bot2 for Peter Zijlstra
2023-05-22 10:27 ` tip-bot2 for Peter Zijlstra
2023-05-15 7:57 ` [PATCH v3 03/11] arch: Introduce arch_{,try_}_cmpxchg128{,_local}() Peter Zijlstra
2023-05-20 10:49 ` [tip: locking/core] " tip-bot2 for Peter Zijlstra
2023-05-22 10:27 ` tip-bot2 for Peter Zijlstra
2023-05-15 7:57 ` [PATCH v3 04/11] instrumentation: Wire up cmpxchg128() Peter Zijlstra
2023-05-20 10:49 ` [tip: locking/core] " tip-bot2 for Peter Zijlstra
2023-05-22 10:27 ` tip-bot2 for Peter Zijlstra
2023-05-15 7:57 ` [PATCH v3 05/11] percpu: Wire up cmpxchg128 Peter Zijlstra
2023-05-20 10:49 ` [tip: locking/core] " tip-bot2 for Peter Zijlstra
2023-05-22 10:27 ` tip-bot2 for Peter Zijlstra
2023-05-25 12:49 ` [PATCH v3 05/11] " Peter Zijlstra
2023-05-25 22:59 ` Petr Tesařík
2023-05-15 7:57 ` [PATCH v3 06/11] x86,amd_iommu: Replace cmpxchg_double() Peter Zijlstra
2023-05-20 10:49 ` [tip: locking/core] " tip-bot2 for Peter Zijlstra
2023-05-22 10:27 ` tip-bot2 for Peter Zijlstra
2023-05-15 7:57 ` [PATCH v3 07/11] x86,intel_iommu: " Peter Zijlstra
2023-05-20 10:49 ` [tip: locking/core] " tip-bot2 for Peter Zijlstra
2023-05-22 10:27 ` tip-bot2 for Peter Zijlstra
2023-05-15 7:57 ` [PATCH v3 08/11] slub: " Peter Zijlstra
2023-05-20 10:49 ` [tip: locking/core] " tip-bot2 for Peter Zijlstra
2023-05-22 10:27 ` tip-bot2 for Peter Zijlstra
2023-05-24 9:32 ` [PATCH v3 08/11] " Peter Zijlstra
2023-05-24 10:13 ` Vlastimil Babka
2023-05-25 10:29 ` Peter Zijlstra
2023-05-25 10:52 ` Arnd Bergmann [this message]
2023-05-25 13:10 ` Peter Zijlstra
2023-05-30 14:22 ` Peter Zijlstra
2023-05-30 19:32 ` Peter Zijlstra
2023-05-15 7:57 ` [PATCH v3 09/11] mm/slub: Fold slab_update_freelist() Peter Zijlstra
2023-05-24 11:58 ` Vlastimil Babka
2023-05-15 7:57 ` [PATCH v3 10/11] arch: Remove cmpxchg_double Peter Zijlstra
2023-05-15 8:52 ` Heiko Carstens
2023-05-20 10:49 ` [tip: locking/core] " tip-bot2 for Peter Zijlstra
2023-05-22 10:27 ` tip-bot2 for Peter Zijlstra
2023-05-15 7:57 ` [PATCH v3 11/11] s390/cpum_sf: Convert to cmpxchg128() Peter Zijlstra
2023-05-20 10:49 ` [tip: locking/core] " tip-bot2 for Peter Zijlstra
2023-05-22 10:27 ` tip-bot2 for Peter Zijlstra
2023-05-15 9:42 ` [PATCH v3 00/11] Introduce cmpxchg128() -- aka. the demise of cmpxchg_double() Arnd Bergmann
2023-05-24 9:39 ` Peter Zijlstra
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