>>>>> On Mon, 26 Apr 2004 16:35:55 -0500, Robin Holt <holt@sgi.com> said: >> In any case, just be careful about not introducing memory attribute >> aliases. You need to be especially careful since the kernel accesses >> memory with granule-sized mappings (normally 64MB page size, but on >> some machines its 16MB). Robin> Be very careful when using uncached memory. On the SGI Robin> systems, we always allocate memory for uncached out of a Robin> seperate granule. We were experiencing memory corruption due Robin> to kernel speculative load which fetched the cache line Robin> dirty. This would result in cache lines that were Robin> occasionally out of date. The problem was resolved on our Robin> kernels by drivers/char/fetchop.c which provides a seperate Robin> device for mapping when you want uncached or write coalesced Robin> memory. Are you just re-stating my caveat about memory-attribute-aliasing or are you saying something else? If the latter, I'm not following. If the former, I certainly agree: memory attribute-aliasing leads to really nasty-to-track-down bugs. Hence, you want to make sure _upfront_ that it doesn't occur. --david - To unsubscribe from this list: send the line "unsubscribe linux-ia64" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.htmlReceived on Mon Apr 26 20:03:39 2004
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