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authorHuacai Chen <chenhuacai@loongson.cn>2025-01-25 18:51:33 +0800
committerHuacai Chen <chenhuacai@loongson.cn>2025-01-25 18:51:33 +0800
commitb62a03049f141061d0397bfa86b74f65985d9338 (patch)
treeb2b6811b70ca4ee66f08ed9b44926ce88f7052ac
parent98e720f77dba6bb702a57f3d8479e6445e34f38c (diff)
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 <lichao@loongson.cn> Signed-off-by: Juxin Gao <gaojuxin@loongson.cn> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
-rw-r--r--arch/loongarch/kernel/cacheinfo.c6
1 files changed, 6 insertions, 0 deletions
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);