Re: cpusets vs cpu-hotplug interaction is broken?

2007-08-29 Thread Gautham R Shenoy
On Wed, Aug 29, 2007 at 02:52:04PM +0400, Oleg Nesterov wrote: > On 08/29, Gautham R Shenoy wrote: > > > > On Tue, Aug 28, 2007 at 05:48:53PM +0400, Oleg Nesterov wrote: > > > (cpu-hotplug experts cc'ed) > > > > > > On 08/25, Oleg Nesterov wrote: > > > > > > > > After the brief look at kernel/cpus

Re: cpusets vs cpu-hotplug interaction is broken?

2007-08-29 Thread Oleg Nesterov
On 08/29, Gautham R Shenoy wrote: > > On Tue, Aug 28, 2007 at 05:48:53PM +0400, Oleg Nesterov wrote: > > (cpu-hotplug experts cc'ed) > > > > On 08/25, Oleg Nesterov wrote: > > > > > > After the brief look at kernel/cpuset.c, it seems that attach_task() > > > should > > > guarantee that the task c

Re: cpusets vs cpu-hotplug interaction is broken?

2007-08-29 Thread Gautham R Shenoy
On Tue, Aug 28, 2007 at 05:48:53PM +0400, Oleg Nesterov wrote: > (cpu-hotplug experts cc'ed) > > On 08/25, Oleg Nesterov wrote: > > > > After the brief look at kernel/cpuset.c, it seems that attach_task() should > > guarantee that the task can't use CPUs outside of cpuset->cpus_allowed. > > > > B

cpusets vs cpu-hotplug interaction is broken?

2007-08-28 Thread Oleg Nesterov
(cpu-hotplug experts cc'ed) On 08/25, Oleg Nesterov wrote: > > After the brief look at kernel/cpuset.c, it seems that attach_task() should > guarantee that the task can't use CPUs outside of cpuset->cpus_allowed. > > But this looks racy wrt sched_setaffinity() which does > > cpus_allowed =