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authorArnaldo Carvalho de Melo <acme@redhat.com>2007-11-21 17:02:58 +0300
committerDavid S. Miller <davem@davemloft.net>2008-01-29 01:54:39 +0300
commitde4d1db369785c29d68915edfee0cb70e8199f4c (patch)
tree78979fc131145d4b2df3cd4721a811784126f05c /lib/pcounter.c
parent0c884439dbd7c895cce61c4974c8868b0f6cd4a1 (diff)
downloadlinux-de4d1db369785c29d68915edfee0cb70e8199f4c.tar.xz
[LIB]: Introduce struct pcounter
This just generalises what was introduced by Eric Dumazet for the struct proto inuse field in 286ab3d46058840d68e5d7d52e316c1f7e98c59f: [NET]: Define infrastructure to keep 'inuse' changes in an efficent SMP/NUMA way. Please look at the comment in there to see the rationale. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'lib/pcounter.c')
-rw-r--r--lib/pcounter.c26
1 files changed, 26 insertions, 0 deletions
diff --git a/lib/pcounter.c b/lib/pcounter.c
new file mode 100644
index 000000000000..93feea598251
--- /dev/null
+++ b/lib/pcounter.c
@@ -0,0 +1,26 @@
+/*
+ * Define default pcounter functions
+ * Note that often used pcounters use dedicated functions to get a speed increase.
+ * (see DEFINE_PCOUNTER/REF_PCOUNTER_MEMBER)
+ */
+
+#include <linux/module.h>
+#include <linux/pcounter.h>
+#include <linux/smp.h>
+
+void pcounter_def_add(struct pcounter *self, int inc)
+{
+ per_cpu_ptr(self->per_cpu_values, smp_processor_id())[0] += inc;
+}
+
+EXPORT_SYMBOL_GPL(pcounter_def_add);
+
+int pcounter_def_getval(const struct pcounter *self)
+{
+ int res = 0, cpu;
+ for_each_possible_cpu(cpu)
+ res += per_cpu_ptr(self->per_cpu_values, cpu)[0];
+ return res;
+}
+
+EXPORT_SYMBOL_GPL(pcounter_def_getval);