]> 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)
commitd84772922392b505bccc2caf0f6740a1d79daea2
treef2fadeb3dbb36f4df2492214c46df2ba32c8eeee
parenta2200a1a728925ec7975c22ebe5470181f223449
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: a92c9d6e7ced ("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