On 08/30/2011 05:38 AM, Xiao Guangrong wrote:
Detecting write-flooding does not work well, when we handle page written, if the last speculative spte is not accessed, we treat the page is write-flooding, however, we can speculative spte on many path, such as pte prefetch, page synced, that means the last speculative spte may be not point to the written page and the written page can be accessed via other sptes, so depends on the Accessed bit of the last speculative spte is not enough Instead of detected page accessed, we can detect whether the spte is accessed after it is written, if the spte is not accessed but it is written frequently, we treat is not a page table or it not used for a long time
The spte may not be accessed, but other sptes in the same page can be accessed. An example is the fixmap area for kmap_atomic(), there will be a lot of pte writes but other sptes will be accessed without going through soft-mmu at all.
I think you have to read the parent_ptes->spte.accessed bits to be sure. -- error compiling committee.c: too many arguments to function -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
