On 07/08/2014 01:43 AM, Dave Hansen wrote: > On 04/24/2014 03:37 AM, Mel Gorman wrote: >>> +Despite the fact that a single individual flush on x86 is >>>> +guaranteed to flush a full 2MB, hugetlbfs always uses the full >>>> +flushes. THP is treated exactly the same as normal memory. >>>> + >> You are the second person that told me this and I felt the manual was >> unclear on this subject. I was told that it might be a documentation bug >> but because this discussion was in a bar I completely failed to follow up >> on it. > > For the record... There's a new version of the Intel SDM out, and it > contains some clarifications. They're the easiest to find in this > document which highlights the deltas from the last version: > >> http://www.intel.com/content/dam/www/public/us/en/documents/manuals/64-ia-32-architectures-software-developers-manual.pdf > > The documentation for invlpg itself has a new footnote, and there's also > a little bit of new text in section "4.10.2.3 Details of TLB Use". > > The footnotes say: > > If the paging structures map the linear address using a page > larger than 4 KBytes and there are multiple TLB entries for > that page (see Section 4.10.2.3), the instruction (invlpg) > invalidates all of them > > I hope that clears up some of the ambiguity over invlpg. > Uh, AFAICT, the invlpg on large page has no clear effect on data retrieving, on all Intel CPU till ivybridge. No testing on later CPUs. -- Thanks Alex -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>