From: David Laight <David.Laight@ACULAB.COM>
To: 'Will Deacon' <will@kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: "linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
"kernel-team@android.com" <kernel-team@android.com>,
Michael Ellerman <mpe@ellerman.id.au>,
Peter Zijlstra <peterz@infradead.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Segher Boessenkool <segher@kernel.crashing.org>,
Christian Borntraeger <borntraeger@de.ibm.com>,
Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
Arnd Bergmann <arnd@arndb.de>
Subject: RE: [RFC PATCH 0/8] Rework READ_ONCE() to improve codegen
Date: Mon, 13 Jan 2020 11:20:50 +0000 [thread overview]
Message-ID: <c1c18e9a4f144c6a92a250a206dfef02@AcuMS.aculab.com> (raw)
In-Reply-To: <20200110165636.28035-1-will@kernel.org>
From: Will Deacon
> Sent: 10 January 2020 16:56
...
> The rough summary of the series is:
>
> * Drop the GCC 4.8 workarounds, so that READ_ONCE() is a
> straightforward dereference of a cast-to-volatile pointer.
What is the effect of using the changed code on older compilers (esp. x86-64)?
Requiring gcc > 4.8 is a significant bump.
David
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Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2020-01-13 11:20 UTC|newest]
Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-10 16:56 [RFC PATCH 0/8] Rework READ_ONCE() to improve codegen Will Deacon
2020-01-10 16:56 ` Will Deacon
2020-01-10 16:56 ` [RFC PATCH 1/8] compiler/gcc: Emit build-time warning for GCC prior to version 4.8 Will Deacon
2020-01-10 17:35 ` Arnd Bergmann
2020-01-10 17:53 ` Joe Perches
2020-01-10 17:53 ` Joe Perches
2020-01-13 14:39 ` Arnd Bergmann
2020-01-13 14:39 ` Arnd Bergmann
2020-01-13 15:35 ` Masahiro Yamada
2020-01-13 15:35 ` Masahiro Yamada
2020-01-13 14:27 ` Will Deacon
2020-01-14 21:39 ` Nick Desaulniers
2020-01-15 10:35 ` David Laight
2020-01-15 10:49 ` Arnd Bergmann
2020-01-10 16:56 ` [RFC PATCH 2/8] netfilter: Avoid assigning 'const' pointer to non-const pointer Will Deacon
2020-01-10 16:56 ` [RFC PATCH 3/8] fault_inject: Don't rely on "return value" from WRITE_ONCE() Will Deacon
2020-01-10 16:56 ` Will Deacon
2020-01-10 16:56 ` [RFC PATCH 4/8] READ_ONCE: Simplify implementations of {READ,WRITE}_ONCE() Will Deacon
2020-01-10 16:56 ` [RFC PATCH 5/8] READ_ONCE: Enforce atomicity for {READ,WRITE}_ONCE() memory accesses Will Deacon
2020-01-10 16:56 ` Will Deacon
2020-01-10 19:24 ` Arnd Bergmann
2020-01-10 19:24 ` Arnd Bergmann
2020-01-13 16:16 ` Will Deacon
2020-01-13 16:16 ` Will Deacon
2020-01-10 16:56 ` [RFC PATCH 6/8] READ_ONCE: Drop pointer qualifiers when reading from scalar types Will Deacon
2020-01-10 18:54 ` Linus Torvalds
2020-01-10 18:54 ` Linus Torvalds
2020-01-13 14:59 ` Will Deacon
2020-01-13 14:59 ` Will Deacon
2020-01-13 17:42 ` Luc Van Oostenryck
2020-01-13 17:42 ` Luc Van Oostenryck
2020-01-13 19:31 ` Linus Torvalds
2020-01-10 16:56 ` [RFC PATCH 7/8] locking/barriers: Use '__unqual_scalar_typeof' for load-acquire macros Will Deacon
2020-01-10 16:56 ` Will Deacon
2020-01-10 19:42 ` Arnd Bergmann
2020-01-13 15:01 ` Will Deacon
2020-01-13 15:01 ` Will Deacon
2020-01-10 16:56 ` [RFC PATCH 8/8] arm64: barrier: Use '__unqual_scalar_typeof' for acquire/release macros Will Deacon
2020-01-10 16:56 ` Will Deacon
2020-01-10 17:45 ` Mark Rutland
2020-01-10 17:58 ` [RFC PATCH 0/8] Rework READ_ONCE() to improve codegen Arnd Bergmann
2020-01-10 17:58 ` Arnd Bergmann
2020-01-10 19:46 ` Arnd Bergmann
2020-01-10 19:46 ` Arnd Bergmann
2020-01-10 20:14 ` Linus Torvalds
2020-01-13 13:03 ` Arnd Bergmann
2020-01-13 13:03 ` Arnd Bergmann
2020-01-13 11:20 ` David Laight [this message]
2020-01-13 12:40 ` Christian Borntraeger
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