From: David Laight <David.Laight@ACULAB.COM>
To: 'Huacai Chen' <chenhuacai@loongson.cn>,
Arnd Bergmann <arnd@arndb.de>,
Huacai Chen <chenhuacai@kernel.org>
Cc: "loongarch@lists.linux.dev" <loongarch@lists.linux.dev>,
"linux-arch@vger.kernel.org" <linux-arch@vger.kernel.org>,
Xuefeng Li <lixuefeng@loongson.cn>, Guo Ren <guoren@kernel.org>,
Xuerui Wang <kernel@xen0n.name>,
Jiaxun Yang <jiaxun.yang@flygoat.com>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] LoongArch: Make -mstrict-align be configurable
Date: Thu, 2 Feb 2023 09:01:34 +0000 [thread overview]
Message-ID: <363cd09a5dcb4deab21f58c19025254f@AcuMS.aculab.com> (raw)
In-Reply-To: <20230202084238.2408516-1-chenhuacai@loongson.cn>
From: Huacai Chen
> Sent: 02 February 2023 08:43
>
> Introduce Kconfig option ARCH_STRICT_ALIGN to make -mstrict-align be
> configurable.
>
> Not all LoongArch cores support h/w unaligned access, we can use the
> -mstrict-align build parameter to prevent unaligned accesses.
>
> This option is disabled by default to optimise for performance, but you
> can enabled it manually if you want to run kernel on systems without h/w
> unaligned access support.
Should there be an associated run-time check during kernel initialisation
that a kernel compiled without -mstrict-align isn't being run on hardware
that doesn't support unaligned accesses.
It can be quite a while before you get a compiler-generated misaligned accesses.
Also isn't there a HAVE_EFFICIENT_MISALIGNED_ACCESS define that would
also need to be set correctly??
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:[~2023-02-02 9:01 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-02 8:42 [PATCH] LoongArch: Make -mstrict-align be configurable Huacai Chen
2023-02-02 9:01 ` David Laight [this message]
2023-02-03 2:00 ` Huacai Chen
2023-02-03 8:46 ` David Laight
2023-02-06 10:28 ` Jianmin Lv
2023-02-07 5:24 ` WANG Xuerui
2023-02-07 10:32 ` Arnd Bergmann
2023-02-07 13:28 ` Jianmin Lv
2023-02-07 14:10 ` Arnd Bergmann
2023-02-08 11:17 ` Huacai Chen
2023-02-02 9:46 ` Arnd Bergmann
2023-02-03 2:08 ` Huacai Chen
2023-02-06 10:33 ` Arnd Bergmann
2023-02-02 10:30 ` WANG Xuerui
2023-02-06 10:24 ` Jianmin Lv
2023-02-06 11:18 ` Xi Ruoyao
2023-02-06 13:13 ` Jianmin Lv
2023-02-06 13:22 ` Arnd Bergmann
2023-02-07 1:13 ` Jianmin Lv
2023-02-06 13:30 ` Xi Ruoyao
2023-02-07 1:27 ` Jianmin Lv
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