On 02/12/2013 06:36 PM, Peter Zijlstra wrote: > On Thu, 2013-01-24 at 11:06 +0800, Alex Shi wrote: >> Current scheduler behavior is just consider the for larger performance >> of system. So it try to spread tasks on more cpu sockets and cpu cores >> >> To adding the consideration of power awareness, the patchset adds >> 2 kinds of scheduler policy: powersaving and balance. They will use >> runnable load util in scheduler balancing. The current scheduling is taken >> as performance policy. >> >> performance: the current scheduling behaviour, try to spread tasks >> on more CPU sockets or cores. performance oriented. >> powersaving: will pack tasks into few sched group until all LCPU in the >> group is full, power oriented. >> balance : will pack tasks into few sched group until group_capacity >> numbers CPU is full, balance between performance and >> powersaving. > > _WHY_ do you start out with so much choice? > > If your power policy is so abysmally poor on performance that you > already know you need a 3rd policy to keep people happy, maybe you're > doing something wrong?
Nope, no much performance yield for both of powersaving and balance policy. Much of testing results in replaying Ingo's email on '0/18' thread -- the cover letter email threads. https://lkml.org/lkml/2013/2/3/353 https://lkml.org/lkml/2013/2/4/735 I introduce a 'balance' policy just because HT thread LCPU in Intel CPU is less then 1 usual cpu power. It is used when someone want to save power but still want tasks have a whole cpu core... > >> +#define SCHED_POLICY_PERFORMANCE (0x1) >> +#define SCHED_POLICY_POWERSAVING (0x2) >> +#define SCHED_POLICY_BALANCE (0x4) >> + >> +extern int __read_mostly sched_policy; > > I'd much prefer: sched_balance_policy. Scheduler policy is a concept > already well defined by posix and we don't need it to mean two > completely different things. > Got it. -- Thanks Alex -- 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/
