Messages in this thread | | | Date | Thu, 13 May 2010 16:22:04 +0530 | From | Balbir Singh <> | Subject | Re: [PATCH/RFC] Have sane default values for cpusets |
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* Dhaval Giani <dhaval.giani@gmail.com> [2010-05-13 12:26:30]:
> On Wed, May 12, 2010 at 9:59 PM, Dhaval Giani <dhaval.giani@gmail.com> wrote: > > On Wed, May 12, 2010 at 9:36 PM, Paul Menage <menage@google.com> wrote: > >> On Wed, May 12, 2010 at 12:29 PM, Dhaval Giani <dhaval.giani@gmail.com> wrote: > >>>> I think the idea is reasonable - the only way that I could see it > >>>> breaking someone would be code that currently does something like: > >>>> > >>>> mkdir A > >>>> mkdir B > >>>> echo 1 > A/mem_exclusive > >>>> echo 1 > B/mem_exclusive > >>>> echo $mems_for_a > A/mems > >>>> echo $mems_for_b > B/mems > >>>> > >>>> The attempts to set the mem_exclusive flags would fail, since A and B > >>>> would both have all of the parent's mems. > >>>> > >>> > >>> But would this not fail otherwise? > >>> > >> > >> Assuming that mems_for_a and mems_for_b were disjoint, it would be > >> fine currently. > >> > > > > Ah my bad. I misread mems_for_a as taking the value from the parent. > > You are right, that was a case I missed. > > > > Hmm, so how do we fix this? Any solutions? Not fixing the kernel > > pushes the problem to the userspace, making it hard for tons of more > > applications to use cgroups without jumping through a lot of hoops. > > > > OK, how about this. Introduce a new option, nodefaults (or some such > name) which would retain the existing behaviour while the default > mount options would moutn cpuset with the defaults. Also, make > > mount -t cpuset cpuset /cpuset > > equivalent to > > mount -t cgroup -onoprefix,nodefaults,cpuset cpuset /cpuset >
Does something like cpusetinherits make more sense.
-- Three Cheers, Balbir
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