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-rw-r--r--drivers/base/cacheinfo.c51
1 files changed, 50 insertions, 1 deletions
diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c
index cbae8be1fe..f1e79263fe 100644
--- a/drivers/base/cacheinfo.c
+++ b/drivers/base/cacheinfo.c
@@ -898,6 +898,48 @@ err:
return rc;
}
+/*
+ * Calculate the size of the per-CPU data cache slice. This can be
+ * used to estimate the size of the data cache slice that can be used
+ * by one CPU under ideal circumstances. UNIFIED caches are counted
+ * in addition to DATA caches. So, please consider code cache usage
+ * when use the result.
+ *
+ * Because the cache inclusive/non-inclusive information isn't
+ * available, we just use the size of the per-CPU slice of LLC to make
+ * the result more predictable across architectures.
+ */
+static void update_per_cpu_data_slice_size_cpu(unsigned int cpu)
+{
+ struct cpu_cacheinfo *ci;
+ struct cacheinfo *llc;
+ unsigned int nr_shared;
+
+ if (!last_level_cache_is_valid(cpu))
+ return;
+
+ ci = ci_cacheinfo(cpu);
+ llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1);
+
+ if (llc->type != CACHE_TYPE_DATA && llc->type != CACHE_TYPE_UNIFIED)
+ return;
+
+ nr_shared = cpumask_weight(&llc->shared_cpu_map);
+ if (nr_shared)
+ ci->per_cpu_data_slice_size = llc->size / nr_shared;
+}
+
+static void update_per_cpu_data_slice_size(bool cpu_online, unsigned int cpu)
+{
+ unsigned int icpu;
+
+ for_each_online_cpu(icpu) {
+ if (!cpu_online && icpu == cpu)
+ continue;
+ update_per_cpu_data_slice_size_cpu(icpu);
+ }
+}
+
static int cacheinfo_cpu_online(unsigned int cpu)
{
int rc = detect_cache_attributes(cpu);
@@ -906,7 +948,12 @@ static int cacheinfo_cpu_online(unsigned int cpu)
return rc;
rc = cache_add_dev(cpu);
if (rc)
- free_cache_attributes(cpu);
+ goto err;
+ update_per_cpu_data_slice_size(true, cpu);
+ setup_pcp_cacheinfo();
+ return 0;
+err:
+ free_cache_attributes(cpu);
return rc;
}
@@ -916,6 +963,8 @@ static int cacheinfo_cpu_pre_down(unsigned int cpu)
cpu_cache_sysfs_exit(cpu);
free_cache_attributes(cpu);
+ update_per_cpu_data_slice_size(false, cpu);
+ setup_pcp_cacheinfo();
return 0;
}