"Owning a car = freedom"
"You need a big truck/SUV to haul things" (it's just a coincidence that people drove much smaller cars before a multibillion dollar deluge of advertising)
"It's consumers' responsibility to reduce plastic pollution by recycling, and recycling is effective" (whoever came up with this one belongs in the PR scumfuck hall of fame)
showing a maverick side
Supporting the status quo = maverick
Totally beside the point, but is it just me or is that article written really strangely? Overall it has a kinda high school newspaper vibe, but in particular the attempts at humor are both awkward and numerous.
The information itself is good, though, so thank you for sharing!
There's a variable that contains the number of cores (called cpus) which is hardcoded to max out at 8, but it doesn't mean that cores aren't utilized beyond 8 cores--it just means that the scheduling scaling factor will not change in either the linear or logarithmic case once you go above that number:
code snippet
/*
* Increase the granularity value when there are more CPUs,
* because with more CPUs the 'effective latency' as visible
* to users decreases. But the relationship is not linear,
* so pick a second-best guess by going with the log2 of the
* number of CPUs.
*
* This idea comes from the SD scheduler of Con Kolivas:
*/
static unsigned int get_update_sysctl_factor(void)
{
unsigned int cpus = min_t(unsigned int, num_online_cpus(), 8);
unsigned int factor;
switch (sysctl_sched_tunable_scaling) {
case SCHED_TUNABLESCALING_NONE:
factor = 1;
break;
case SCHED_TUNABLESCALING_LINEAR:
factor = cpus;
break;
case SCHED_TUNABLESCALING_LOG:
default:
factor = 1 + ilog2(cpus);
break;
}
return factor;
}
The core claim is this:
It’s problematic that the kernel was hardcoded to a maximum of 8 cores (scaling factor of 4). It can’t be good to reschedule hundreds of tasks every few milliseconds, maybe on a different core, maybe on a different die. It can’t be good for performance and cache locality.
On this point, I have no idea (hope someone more knowledgeable will weigh in). But I'd say the headline is misleading at best.
A/B/O gang