From: catalin.marinas@arm.com (Catalin Marinas)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] ARM: Add TLB flushing for both entries in a PMD
Date: Wed, 23 Nov 2011 10:45:31 +0000 [thread overview]
Message-ID: <20111123104531.GC29609@arm.com> (raw)
In-Reply-To: <004d01cca9c9$aeeb0420$0cc10c60$%youn@samsung.com>
On Wed, Nov 23, 2011 at 10:21:37AM +0000, Changhwan Youn wrote:
> I have tested this patch on several exynos machines which
> have a9 cores and it worked fine.
> Though I'm not sure that android boot and running simple applications
> are enough test for this patch.
Thanks for testing but the A9 would work fine without this patch. The
problem is on A15 where level 1 page table entries (pgd) are cached by
the TLB independently of level 2 entries (pte). The original code is
only flushing one entry in level 1 rather than 2.
The problem was visible with a stress-test application doing mmap/munmap
and then continuously getting level 2 translation fault even if the page
table looked fine to the kernel (because of stale level 1 entry in the
TLB).
LPAE is not affected, only the classic page table format.
--
Catalin
next prev parent reply other threads:[~2011-11-23 10:45 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-11-16 10:38 [PATCH] ARM: Add TLB flushing for both entries in a PMD Catalin Marinas
2011-11-23 10:21 ` Changhwan Youn
2011-11-23 10:45 ` Catalin Marinas [this message]
2011-11-25 8:50 ` Changhwan Youn
2011-11-25 10:17 ` Catalin Marinas
2011-11-28 8:00 ` Changhwan Youn
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