Hey, On Wed, Apr 22, 2015 at 05:42:12PM +0200, Peter Zijlstra wrote: > If, as per the below you want to use the bitmap ops; it needs be > unsigned long.
Ah, right. > > > static struct cftype cgroup_dfl_base_files[]; > > > +#define for_each_subsys_which(ss_mask, ss, ssid) \ > > > + for_each_subsys((ss), (ssid)) \ > > > + if ((ss_mask) & (1 << (ssid))) > > > > Maybe using for_each_set_bit() is better? > > > > #define for_each_subsys_which(ss_mask, ss, ssid) \ > > for_each_set_bit(ssid, &(ss_mask), CGROUP_SUBSYS_COUNT) \ > > if ((ss) = group_subsys[ssid] && false) \ > > ; \ > > else > > Clever that ;-) Thanks. It kinda bothers me that for_each_set_bit() doesn't collapse to combo of ffs() + clearing bit off of a temp mask when size is const and <= ulong, which would be quite a bit lighter. Right now it'd be calling into generic find_first/next_bit() functions unconditionally. Ah well, it can be optimized later. -- tejun -- 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/
