On Tue, Sep 27, 2011 at 3:03 AM, Balbir Singh <bsingharora@xxxxxxxxx> wrote: > On Sat, Sep 17, 2011 at 9:09 AM, Michel Lespinasse <walken@xxxxxxxxxx> wrote: >> Patch 3 introduces page_referenced_kstaled(), which is similar to >> page_referenced() but is used for idle page tracking rather than >> for memory reclaimation. Since both functions clear the pte_young bits >> and we don't want them to interfere with each other, two new page flags >> are introduced that track when young pte references have been cleared by >> each of the page_referenced variants. > > Sorry, I have trouble parsing this sentence, could you elaborate on "when"? page_referenced() indicates if a page was accessed since the previous page_referenced() call. page_referenced_kstaled() indicates if a page was accessed since the previous page_referenced_kstaled() call. Both of the functions need to clear PTE young bits; however we don't want the two functions to interfere with each other. To achieve this, we add two page bits to indicate when a young PTE has been observed by one of the functions but not by the other. -- Michel "Walken" Lespinasse A program is never fully debugged until the last user dies. -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>