]> git.baikalelectronics.ru Git - kernel.git/commit
sched,x86: Don't use cluster topology for x86 hybrid CPUs
authorPeter Zijlstra <peterz@infradead.org>
Sat, 4 Dec 2021 09:14:02 +0000 (10:14 +0100)
committerPeter Zijlstra <peterz@infradead.org>
Wed, 8 Dec 2021 21:15:37 +0000 (22:15 +0100)
commitc64380cab52e16999118514e6528234ef107a2c9
treef2fadeb3dbb36f4df2492214c46df2ba32c8eeee
parentbcaa5780ddbeacad7e998e7957fc9a3a5a94c857
sched,x86: Don't use cluster topology for x86 hybrid CPUs

For x86 hybrid CPUs like Alder Lake, the order of CPU selection should
be based strictly on CPU priority.  Don't include cluster topology for
hybrid CPUs to avoid interference with such CPU selection order.

On Alder Lake, the Atom CPU cluster has more capacity (4 Atom CPUs) vs
Big core cluster (2 hyperthread CPUs). This could potentially bias CPU
selection towards Atom over Big Core, when Big core CPU has higher
priority.

Fixes: 09c4ff723f4d ("sched: Add cluster scheduler level for x86")
Suggested-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Tim Chen <tim.c.chen@linux.intel.com>
Tested-by: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Link: https://lkml.kernel.org/r/20211204091402.GM16608@worktop.programming.kicks-ass.net
arch/x86/kernel/smpboot.c