diff options
| author | Arnaldo Carvalho de Melo <acme@redhat.com> | 2007-11-21 22:02:58 +0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2008-01-28 14:54:39 -0800 |
| commit | de4d1db369785c29d68915edfee0cb70e8199f4c (patch) | |
| tree | 78979fc131145d4b2df3cd4721a811784126f05c /lib | |
| parent | 0c884439dbd7c895cce61c4974c8868b0f6cd4a1 (diff) | |
| download | lwn-de4d1db369785c29d68915edfee0cb70e8199f4c.tar.gz lwn-de4d1db369785c29d68915edfee0cb70e8199f4c.zip | |
[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')
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/pcounter.c | 26 |
2 files changed, 27 insertions, 0 deletions
diff --git a/lib/Makefile b/lib/Makefile index 89841dc9d91c..543f2502b60a 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -61,6 +61,7 @@ obj-$(CONFIG_TEXTSEARCH_KMP) += ts_kmp.o obj-$(CONFIG_TEXTSEARCH_BM) += ts_bm.o obj-$(CONFIG_TEXTSEARCH_FSM) += ts_fsm.o obj-$(CONFIG_SMP) += percpu_counter.o +obj-$(CONFIG_SMP) += pcounter.o obj-$(CONFIG_AUDIT_GENERIC) += audit.o obj-$(CONFIG_SWIOTLB) += swiotlb.o 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); |