On 2013/8/13 23:05, Tejun Heo wrote: > On Tue, Aug 13, 2013 at 09:17:53AM +0800, Li Zefan wrote: >> Now cgroup core gets a reference to the css when a cgroup file is >> opened(), and the reference is dropped at file release. so it's >> guaranteed the cpuset is online during the write function. > > Hmmm... it doesn't really guarantee that as css's can be offlined with > residual css refcnts, os the css may well be offlined by the time it > reaches the rw functions. What's guaranteed is that their refcnts > wouldn't be zero.
Oh, right. But most controllers don't check this in those read/write functions. It shoudn't do any harm not checking online/offline status. > Eventually we need to implement proper sever > semantics (probably by replacing the custom fs implementation with > sysfs) but right now controllers still need to deal with offline > css's. > > Thanks. > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
