Re: [PATCH] flush_cache_page while pte valid
Rik van Riel (riel@conectiva.com.br)
Tue, 12 Nov 2002 12:49:50 -0200 (BRST)
On Mon, 11 Nov 2002, David S. Miller wrote:
> From: Hugh Dickins <hugh@veritas.com>
> Date: Tue, 12 Nov 2002 06:53:04 +0000 (GMT)
>
> Thanks for shedding light on that; but I'm still wondering if there
> might be data loss if userspace modifies the page in the tiny window
> between correctly positioned flush_cache_page and pte invalidation?
>
> The flush merely writes back the data, a copy-back operation, fully L2
> cache coherent. All cpus will see correct data if an intermittant
> store occurs.
The CPUs will, but the harddisk might not.
We really need to get this right in the swapout path.
regards,
Rik
--
Bravely reimplemented by the knights who say "NIH".
http://www.surriel.com/ http://distro.conectiva.com/
Current spamtrap: <a href=mailto:"october@surriel.com">october@surriel.com</a>
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/