On Thu, Jul 29, 2010 at 5:22 PM, Daniel Lezcano <daniel.lezcano@xxxxxxx>wrote: > On 07/29/2010 04:35 PM, Nathan Lynch wrote: > > On Thu, 2010-07-29 at 14:30 +0200, Daniel Lezcano wrote: > > > >> Hi all, > >> > >> I noticed all the tasks of the host are listed in /proc/timer_stats > >> These information is not virtualized neither isolated within a > container. > >> > >> I was expecting to see only the tasks in the container with the > >> corresponding pids. > >> > >> I am not sure this is something critical, but the usage of powertop in > >> the container shows all the tasks of the system. > >> > >> While looking at the code in kernel/time/timer.c, it is not obvious to > >> fix this isolation because it is the pid number which is stored in a > >> list, so there is not enough informations to discriminate the pid > >> namespace against the current one. > >> > >> I am wondering if: > >> > >> 1) is it worth to isolate these informations ? (IMHO, yes). > >> 2) should the stats be stored per pid namespace or adding an hash > >> value + pid namespace as a key in the timer stats list ? > >> > > Well, powertop is used for monitoring and modifying global system > > characteristics (e.g. processor C states, USB autosuspend) that don't > > make sense to virtualize. Many events in /proc/timer_stats are > > accocunted to pid 0 (swapper/idle). I think the question is whether a > > pidns-relative slice of timer events will be useful or just confusing. > > > > IMHO I find confusing to see all the applications name/pid running on > the whole system (host + containers) from a container. Even if these > applications are not accessible, that gives informations to the > container on what is running on the system and I think we should > consider that as a security breach. > > We can just "hide" the content of this file for a pid namespace > different of the init pid namespace, but that may suppress the > possibility to investigate with powertop the consumption of a specific > appliance, as accurate as it could be... > Hi Daniel, I wouldn't worry too much about powertop http://www.phoronix.com/scan.php?page=article&item=powertop_2010_test&num=1 br. -- Marc _______________________________________________ Containers mailing list Containers@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/containers
