From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: Discontiguous memory and cacheflush
Date: Mon, 13 Aug 2012 17:00:08 +0100 [thread overview]
Message-ID: <20120813160008.GA30302@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <5029126C.5000202@arm.com>
On Mon, Aug 13, 2012 at 03:42:52PM +0100, Jonathan Austin wrote:
> On my system the cacheflush(2) documentation suggests it is MIPS only:
> "This Linux-specific system call is only available on MIPS based
> systems. It should not be used in programs intended to be portable."
It's been part of the ARM kernel API for a very long time.
> As you've established by looking at the code, on ARM we intentionally
> attempt to flush only the part of the given range that occurs inside the
> vma containing 'start'.
It's intention is to support self-modifying userspace code only and also
intended to be used over a _short_ range of addresses only - it works by
flushing each _individual_ cache line over the range of addreses
requested.
If it's going to be used for significantly larger areas, then we need to
think about imposing a limit, upon which we just flush the entire cache
and be done with it.
next prev parent reply other threads:[~2012-08-13 16:00 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <447177957.1189939.1344577602635.JavaMail.root@mozilla.com>
2012-08-10 5:52 ` Discontiguous memory and cacheflush Martin Rosenberg
2012-08-13 14:42 ` Jonathan Austin
2012-08-13 16:00 ` Russell King - ARM Linux [this message]
2012-08-15 22:08 ` Martin Rosenberg
2012-08-16 8:27 ` Dave Martin
2012-08-16 9:19 ` Russell King - ARM Linux
2012-08-16 9:43 ` Dave Martin
2012-08-17 15:53 ` Jonathan Austin
2012-08-17 21:03 ` Russell King - ARM Linux
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