On Thu, 12 Apr 2007 16:10:50 -0700 William Lee Irwin III <[EMAIL PROTECTED]> wrote: >> This solves a real-life problem for Oracle system monitoring software >> (specifically EM). Among the tasks it must carry out is determining >> per-process memory footprint of a set of cooperating tasks (i.e. Oracle >> processes). RSS is inadequate for this due to page sharing; this work >> provides sufficient information to determine what EM needs.
On Thu, Apr 12, 2007 at 04:32:35PM -0700, Andrew Morton wrote: > Not a good idea to expose raw flags in this manner - it changes at the drop > of a hat. We'd need to also expose the kernel's PG_foo-to-bitnumber > mapping to make this viable. > Not a good idea to use page->_count: page_count() will be more stable. > Otherwise OK, I guess: the interpretation of the page refcount is unlikely > to change much over time. EM wants to determine page_mapcount() for the most part for the purposes of determining "uniquely attributable RSS" (my ca. 2004 nomenclature) or "proportional RSS" (mpm's more recent nomenclature); as things now stand it will have to infer them by maintaining a table of pfn's and mappings thereof, but at least that can be done with it. -- wli - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
