Messages in this thread | | | Date | Thu, 17 Aug 2006 20:12:30 +0400 | From | Kir Kolyshkin <> | Subject | Re: [Devel] Re: [RFC][PATCH 7/7] UBC: proc interface |
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Greg KH wrote: > On Thu, Aug 17, 2006 at 05:43:16PM +0400, Kirill Korotaev wrote: > >>> On Wed, Aug 16, 2006 at 07:44:30PM +0400, Kirill Korotaev wrote: >>> >>> >>>> Add proc interface (/proc/user_beancounters) allowing to see current >>>> state (usage/limits/fails for each UB). Implemented via seq files. >>>> >>> Ugh, why /proc? This doesn't have anything to do with processes, just >>> users, right? What's wrong with /sys/kernel/ instead? >>> >> We can move it, if there are much objections. >> > > I am objecting. /proc is for processes so do not add any new files > there that do not deal with processes. > > >>> Or /sys/kernel/debug/user_beancounters/ in debugfs as this is just a >>> debugging thing, right? >>> >> debugfs is usually OFF imho. >> > > No, distros enable it. > > >> you don't export meminfo information in debugfs, correct? >> > > That is because the meminfo is tied to processes, or was added to proc > before debugfs came about. > > Then how about just /sys/kernel/ instead and use sysfs? Just remember, > one value per file please. > I see two problems with that. But let me first describe the current /proc/user_beancounters. This is how it looks like from inside a container:
# cat /proc/user_beancounters Version: 2.5 uid resource held maxheld barrier limit failcnt 123: kmemsize 836919 1005343 2752512 2936012 0 lockedpages 0 0 32 32 0 privvmpages 4587 7289 49152 53575 0 ............(more lines like that).........................................
I.e. a container owner can take a glance over the current parameters, their usage and (the thing that is really important) fail counters. Fail counter increases each time a parameter hits the limit. This is very straightforward way for container's owner to see if everything is OK or not.
So, the problems with /sys are:
(1) Gettng such info from 40+ files requires at least some script, while now cat is just fine.
(2) Do we want to virtualize sysfs and enable /sys for every container? Note that user_beancounters statistics is really needed for container's owner to see. At the same time, container's owner should not be able to modify it -- so we should end up with read/write ubc entries for the host system and read-only ones for the container.
Taking into account those two issues, current /proc/user_beancounters might be not that bad. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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