On 12-Sep 19:42, Peter Zijlstra wrote: > On Wed, Sep 12, 2018 at 06:35:15PM +0100, Patrick Bellasi wrote: > > On 12-Sep 18:12, Peter Zijlstra wrote: > > > > No idea; but if you want to go all fancy you can replace he whole > > > uclamp_map thing with something like: > > > > > > struct uclamp_map { > > > union { > > > struct { > > > unsigned long v : 10; > > > unsigned long c : BITS_PER_LONG - 10; > > > }; > > > atomic_long_t s; > > > }; > > > }; > > > > That sounds really cool and scary at the same time :) > > > > The v:10 requires that we never set SCHED_CAPACITY_SCALE>1024 > > or that we use it to track a percentage value (i.e. [0..100]). > > Or we pick 11 bits, it seems unlikely that capacity be larger than 2k.
Just remembered a past experience where we had unaligned access traps on some machine because... don't you see any potentially issue on using bitfleds like you suggest above ? I'm thinking to: commit 317d359df95d ("sched/core: Force proper alignment of 'struct util_est'") -- #include <best/regards.h> Patrick Bellasi