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/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]