On Tue, Dec 15, 2015 at 04:23:18PM +0000, Catalin Marinas wrote: > On Tue, Dec 15, 2015 at 03:57:37PM +0000, Mark Rutland wrote: > > On Tue, Dec 15, 2015 at 03:46:51PM +0000, Juri Lelli wrote: > > > On 15/12/15 15:32, Mark Rutland wrote: > > > > On Tue, Dec 15, 2015 at 03:08:13PM +0000, Mark Brown wrote: > > > > > My expectation is that we just need good enough, not perfect, and that > > > > > seems to match what Juri is saying about the expectation that most of > > > > > the fine tuning is done via other knobs. > > > > > > > > My expectation is that if a ballpark figure is good enough, it should be > > > > possible to implement something trivial like bogomips / loop_per_jiffy > > > > calculation. > > > > > > I didn't really followed that, so I might be wrong here, but isn't > > > already happened a discussion about how we want/like to stop exposing > > > bogomips info or rely on it for anything but in kernel delay loops? > > > > I meant that we could have a benchmark of that level of complexity, > > rather than those specific values. > > Or we could simply let user space use whatever benchmarks or hard-coded > values it wants and set the capacity via sysfs (during boot). By > default, the kernel would assume all CPUs equal.
I assume that a userspace override would be available regardless of whatever mechanism the kernel uses to determine relative performance/effinciency. I am not opposed to that mechanism being "assume equal". Mark. -- 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/