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authorH. Peter Anvin <hpa@zytor.com>2009-08-26 17:17:51 -0700
committerH. Peter Anvin <hpa@zytor.com>2009-08-26 17:24:28 -0700
commitb855192c08fcb14adbc5d3a7cab182022d433cca (patch)
tree3a10cafbfbf98cafacf667eb218c71300b351bfa /include/linux/nodemask.h
parentd886c73cd4cf02a71e1650cbcb6176799d78aac1 (diff)
parent3e0e1e9c5a327d4dba8490d83ef55c0564e6e8a7 (diff)
downloadop-kernel-dev-b855192c08fcb14adbc5d3a7cab182022d433cca.zip
op-kernel-dev-b855192c08fcb14adbc5d3a7cab182022d433cca.tar.gz
Merge branch 'x86/urgent' into x86/pat
Reason: Change to is_new_memtype_allowed() in x86/urgent Resolved semantic conflicts in: arch/x86/mm/pat.c arch/x86/mm/ioremap.c Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'include/linux/nodemask.h')
-rw-r--r--include/linux/nodemask.h28
1 files changed, 28 insertions, 0 deletions
diff --git a/include/linux/nodemask.h b/include/linux/nodemask.h
index 829b94b..b359c4a 100644
--- a/include/linux/nodemask.h
+++ b/include/linux/nodemask.h
@@ -82,6 +82,12 @@
* to generate slightly worse code. So use a simple one-line #define
* for node_isset(), instead of wrapping an inline inside a macro, the
* way we do the other calls.
+ *
+ * NODEMASK_SCRATCH
+ * When doing above logical AND, OR, XOR, Remap operations the callers tend to
+ * need temporary nodemask_t's on the stack. But if NODES_SHIFT is large,
+ * nodemask_t's consume too much stack space. NODEMASK_SCRATCH is a helper
+ * for such situations. See below and CPUMASK_ALLOC also.
*/
#include <linux/kernel.h>
@@ -473,4 +479,26 @@ static inline int num_node_state(enum node_states state)
#define for_each_node(node) for_each_node_state(node, N_POSSIBLE)
#define for_each_online_node(node) for_each_node_state(node, N_ONLINE)
+/*
+ * For nodemask scrach area.(See CPUMASK_ALLOC() in cpumask.h)
+ */
+
+#if NODES_SHIFT > 8 /* nodemask_t > 64 bytes */
+#define NODEMASK_ALLOC(x, m) struct x *m = kmalloc(sizeof(*m), GFP_KERNEL)
+#define NODEMASK_FREE(m) kfree(m)
+#else
+#define NODEMASK_ALLOC(x, m) struct x _m, *m = &_m
+#define NODEMASK_FREE(m)
+#endif
+
+/* A example struture for using NODEMASK_ALLOC, used in mempolicy. */
+struct nodemask_scratch {
+ nodemask_t mask1;
+ nodemask_t mask2;
+};
+
+#define NODEMASK_SCRATCH(x) NODEMASK_ALLOC(nodemask_scratch, x)
+#define NODEMASK_SCRATCH_FREE(x) NODEMASK_FREE(x)
+
+
#endif /* __LINUX_NODEMASK_H */
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