Messages in this thread | | | Date | Thu, 28 Dec 2006 10:13:11 +0000 | From | Russell King <> | Subject | Re: [PATCH] mm: fix page_mkclean_one |
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On Wed, Dec 27, 2006 at 10:20:20PM -0700, Gordon Farquharson wrote: > I have run the program a few times, and the output is pretty > consistent. However, when I increase the target size, the difference > between the expected and actual values is larger. > > Written as (749)935(738) > Chunk 1113 corrupted (1-1455) (2965-323) > Expected 89, got 93
This is not the corruption Linus is after. Note that the corruption starts at offset '1'. Also note that:
89 = 1113 & 255 93 = 1113 & 255 | (1113 >> 8)
and if you look at glibc's memset() function, you'll notice that's exactly what you expect if you pass a non-8bit value to it. Ergo, what you're seeing is utterly expected given glibc's memset() implementation on ARM.
Fixing Linus' test program to pass nr & 255 to memset results in clean passes on 2.6.9 on TheCus N2100 (IOP8032x) and 2.6.16.9 StrongARM machines (as would be expected.)
-- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: - 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/
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