On Fri, Feb 23, 2018 at 12:11 AM, Michal Hocko <mhocko@xxxxxxxxxx> wrote: > On Wed 21-02-18 18:49:35, Daniel Colascione wrote: > [...] >> For more context: on Android, we've historically scanned each processes's >> address space using /proc/pid/smaps (and /proc/pid/smaps_rollup more >> recently) to extract memory management statistics. We're looking at >> replacing this mechanism with the new /proc/pid/status per-memory-type >> (e.g., anonymous, file-backed) counters so that we can be even more >> efficient, but we'd like the counts we collect to be accurate. > > If you need the accuracy then why don't you simply make > SPLIT_RSS_COUNTING configurable and disable it in your setup? I considered that option, but it feels like a last resort. I think agreement between /proc/pid/status and /proc/pid/smaps is a correctness issue, and I'd prefer to fix the correctness issue globally. That said, *deleting* the SPLIT_RSS_COUNTING code would be nice and simple. How sure are we that the per-task accounting is really needed? Maybe I'm wrong, but I feel like taking page faults will touch per-mm data structures anyway, so one additional atomic update on the mm shouldn't hurt all that much. -- 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>
