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| author | Srikar Dronamraju <srikar@linux.vnet.ibm.com> | 2023-12-14 23:37:14 +0530 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2023-12-15 13:51:34 +1100 |
| commit | 0e93f1c780e8fd315f1262467b7d35eb6f766d2f (patch) | |
| tree | 76217c56dae9ede4390bdec933b5ac87a6d03fa2 /arch/powerpc/kernel/smp.c | |
| parent | fd535a858ebeb1f478b1d065b6c057f52aad483a (diff) | |
| download | linux-0e93f1c780e8fd315f1262467b7d35eb6f766d2f.tar.gz | |
powerpc/smp: Avoid asym packing within thread_group of a core
PowerVM Hypervisor will schedule at a core granularity. However each
core can have more than one thread_groups. For better utilization in
case of a shared processor, its preferable for the scheduler to pack to
the lowest core. However there is no benefit of moving a thread between
two thread groups of the same core.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231214180720.310852-5-srikar@linux.vnet.ibm.com
Diffstat (limited to 'arch/powerpc/kernel/smp.c')
| -rw-r--r-- | arch/powerpc/kernel/smp.c | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c index aea1496272097d..9d8bb9a084bd90 100644 --- a/arch/powerpc/kernel/smp.c +++ b/arch/powerpc/kernel/smp.c @@ -1763,6 +1763,19 @@ void __init smp_cpus_done(unsigned int max_cpus) set_sched_topology(powerpc_topology); } +/* + * For asym packing, by default lower numbered CPU has higher priority. + * On shared processors, pack to lower numbered core. However avoid moving + * between thread_groups within the same core. + */ +int arch_asym_cpu_priority(int cpu) +{ + if (static_branch_unlikely(&splpar_asym_pack)) + return -cpu / threads_per_core; + + return -cpu; +} + #ifdef CONFIG_HOTPLUG_CPU int __cpu_disable(void) { |