diff options
| -rw-r--r-- | mm/allocpercpu.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/mm/allocpercpu.c b/mm/allocpercpu.c index 7e58322b713..b0012e27fea 100644 --- a/mm/allocpercpu.c +++ b/mm/allocpercpu.c @@ -6,6 +6,10 @@ #include <linux/mm.h> #include <linux/module.h> +#ifndef cache_line_size +#define cache_line_size() L1_CACHE_BYTES +#endif + /** * percpu_depopulate - depopulate per-cpu data for given cpu * @__pdata: per-cpu data to depopulate @@ -52,6 +56,11 @@ void *percpu_populate(void *__pdata, size_t size, gfp_t gfp, int cpu) struct percpu_data *pdata = __percpu_disguise(__pdata); int node = cpu_to_node(cpu); + /* + * We should make sure each CPU gets private memory. + */ + size = roundup(size, cache_line_size()); + BUG_ON(pdata->ptrs[cpu]); if (node_online(node)) pdata->ptrs[cpu] = kmalloc_node(size, gfp|__GFP_ZERO, node); @@ -98,7 +107,11 @@ EXPORT_SYMBOL_GPL(__percpu_populate_mask); */ void *__percpu_alloc_mask(size_t size, gfp_t gfp, cpumask_t *mask) { - void *pdata = kzalloc(nr_cpu_ids * sizeof(void *), gfp); + /* + * We allocate whole cache lines to avoid false sharing + */ + size_t sz = roundup(nr_cpu_ids * sizeof(void *), cache_line_size()); + void *pdata = kzalloc(sz, gfp); void *__pdata = __percpu_disguise(pdata); if (unlikely(!pdata)) |