X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=mm%2Fallocpercpu.c;h=f4026bae6eedadb9e077e3500480fc47feb25624;hb=551395ae667d699189014f762355e9131fc03e79;hp=7e58322b7134ff1d04e40269e030bdd53e1c87f6;hpb=7924e4f6519dd5b349ed146fe9fe35206730be67;p=pandora-kernel.git

diff --git a/mm/allocpercpu.c b/mm/allocpercpu.c
index 7e58322b7134..f4026bae6eed 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);
@@ -73,9 +82,10 @@ EXPORT_SYMBOL_GPL(percpu_populate);
 int __percpu_populate_mask(void *__pdata, size_t size, gfp_t gfp,
 			   cpumask_t *mask)
 {
-	cpumask_t populated = CPU_MASK_NONE;
+	cpumask_t populated;
 	int cpu;
 
+	cpus_clear(populated);
 	for_each_cpu_mask(cpu, *mask)
 		if (unlikely(!percpu_populate(__pdata, size, gfp, cpu))) {
 			__percpu_depopulate_mask(__pdata, &populated);
@@ -98,7 +108,11 @@ 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))