From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] arm: align shared memory unconditionally to the SHMLBA boundary
Date: Mon, 15 Jul 2013 19:08:46 +0100 [thread overview]
Message-ID: <20130715180846.GV24642@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <20130715173238.GJ1730@moon>
On Mon, Jul 15, 2013 at 09:32:38PM +0400, Cyrill Gorcunov wrote:
> On Tue, Feb 19, 2013 at 10:11:09AM +0400, Alexander Kartashov wrote:
> > Currently IPC SHM works in a strange way on ARM:
> > the syscall sys_shmat() requires the argument shmaddr
> > be SHMLBA-aligned (ARM has the macro __ARCH_FORCE_SHMLBA
> > unconditionally defined) but allocates memory that
> > isn't SHMLBA-aligned because the value of memory alignment
> > depends on presense of certain cache aliases.
>
> Hi guys, is there some conclusion on this patch? It has been sent
> almost 5 months back ;)
It's pointless. The alignment is only required for CPUs which have
aliasing caches. What the code does in mmap() is correct. However,
we can't dynamically select this in the SHM code.
next prev parent reply other threads:[~2013-07-15 18:08 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-02-19 6:11 [PATCH] arm: align shared memory unconditionally to the SHMLBA boundary Alexander Kartashov
2013-07-15 17:32 ` Cyrill Gorcunov
2013-07-15 18:08 ` Russell King - ARM Linux [this message]
2013-07-15 18:57 ` Cyrill Gorcunov
2013-07-16 5:37 ` Alexander Kartashov
2013-07-16 9:53 ` Cyrill Gorcunov
2013-07-16 10:22 ` Alexander Kartashov
2013-07-16 10:36 ` Russell King - ARM Linux
2013-07-16 10:47 ` Alexander Kartashov
2013-07-16 11:07 ` Russell King - ARM Linux
2013-07-16 13:12 ` Alexander Kartashov
2013-08-16 8:20 ` Alexander Kartashov
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