From b62a03049f141061d0397bfa86b74f65985d9338 Mon Sep 17 00:00:00 2001 From: Huacai Chen Date: Sat, 25 Jan 2025 18:51:33 +0800 Subject: [PATCH] LoongArch: Correct the cacheinfo sharing information SMT cores and their sibling cores share the same L1 and L2 private caches (of course last level cache is also shared), so correct the cacheinfo sharing information to let shared_cpu_map correctly reflect this relationship. Below is the output of "lscpu" on Loongson-3A6000 (4 cores, 8 threads). 1. Before patch: L1d: 512 KiB (8 instances) L1i: 512 KiB (8 instances) L2: 2 MiB (8 instances) L3: 16 MiB (1 instance) 2. After patch: L1d: 256 KiB (4 instances) L1i: 256 KiB (4 instances) L2: 1 MiB (4 instances) L3: 16 MiB (1 instance) Reported-by: Chao Li Signed-off-by: Juxin Gao Signed-off-by: Huacai Chen --- arch/loongarch/kernel/cacheinfo.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/loongarch/kernel/cacheinfo.c b/arch/loongarch/kernel/cacheinfo.c index c7988f757281..8e231b0d2cd6 100644 --- a/arch/loongarch/kernel/cacheinfo.c +++ b/arch/loongarch/kernel/cacheinfo.c @@ -51,6 +51,12 @@ static void cache_cpumap_setup(unsigned int cpu) continue; sib_leaf = sib_cpu_ci->info_list + index; + /* SMT cores share all caches */ + if (cpus_are_siblings(i, cpu)) { + cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map); + cpumask_set_cpu(i, &this_leaf->shared_cpu_map); + } + /* Node's cores share shared caches */ if (cache_leaves_are_shared(this_leaf, sib_leaf)) { cpumask_set_cpu(cpu, &sib_leaf->shared_cpu_map); cpumask_set_cpu(i, &this_leaf->shared_cpu_map); -- 2.50.1