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authorDavid S. Miller <davem@davemloft.net>2008-03-17 23:44:31 -0700
committerDavid S. Miller <davem@davemloft.net>2008-03-17 23:44:31 -0700
commit2f633928cbba8a5858bb39b11e7219a41b0fbef5 (patch)
tree9a82f4b7f2c3afe4b0208d8e44ea61bae90a7d22 /mm/allocpercpu.c
parent5e226e4d9016daee170699f8a4188a5505021756 (diff)
parentbde4f8fa8db2abd5ac9c542d76012d0fedab050f (diff)
downloadop-kernel-dev-2f633928cbba8a5858bb39b11e7219a41b0fbef5.zip
op-kernel-dev-2f633928cbba8a5858bb39b11e7219a41b0fbef5.tar.gz
Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
Diffstat (limited to 'mm/allocpercpu.c')
-rw-r--r--mm/allocpercpu.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/mm/allocpercpu.c b/mm/allocpercpu.c
index 7e58322..b0012e2 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))
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