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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-01-29 22:54:01 +1100 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-01-29 22:54:01 +1100 |
| commit | 0ba6c33bcddc64a54b5f1c25a696c4767dc76292 (patch) | |
| tree | 62e616f97a4762d8e75bf732e4827af2d15d52c5 /include/linux/pcounter.h | |
| parent | 21af0297c7e56024a5ccc4d8ad2a590f9ec371ba (diff) | |
| parent | 85040bcb4643cba578839e953f25e2d1965d83d0 (diff) | |
| download | kernel-crypto-0ba6c33bcddc64a54b5f1c25a696c4767dc76292.tar.gz kernel-crypto-0ba6c33bcddc64a54b5f1c25a696c4767dc76292.tar.xz kernel-crypto-0ba6c33bcddc64a54b5f1c25a696c4767dc76292.zip | |
Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6.25
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6.25: (1470 commits)
[IPV6] ADDRLABEL: Fix double free on label deletion.
[PPP]: Sparse warning fixes.
[IPV4] fib_trie: remove unneeded NULL check
[IPV4] fib_trie: More whitespace cleanup.
[NET_SCHED]: Use nla_policy for attribute validation in ematches
[NET_SCHED]: Use nla_policy for attribute validation in actions
[NET_SCHED]: Use nla_policy for attribute validation in classifiers
[NET_SCHED]: Use nla_policy for attribute validation in packet schedulers
[NET_SCHED]: sch_api: introduce constant for rate table size
[NET_SCHED]: Use typeful attribute parsing helpers
[NET_SCHED]: Use typeful attribute construction helpers
[NET_SCHED]: Use NLA_PUT_STRING for string dumping
[NET_SCHED]: Use nla_nest_start/nla_nest_end
[NET_SCHED]: Propagate nla_parse return value
[NET_SCHED]: act_api: use PTR_ERR in tcf_action_init/tcf_action_get
[NET_SCHED]: act_api: use nlmsg_parse
[NET_SCHED]: act_api: fix netlink API conversion bug
[NET_SCHED]: sch_netem: use nla_parse_nested_compat
[NET_SCHED]: sch_atm: fix format string warning
[NETNS]: Add namespace for ICMP replying code.
...
Diffstat (limited to 'include/linux/pcounter.h')
| -rw-r--r-- | include/linux/pcounter.h | 74 |
1 files changed, 74 insertions, 0 deletions
diff --git a/include/linux/pcounter.h b/include/linux/pcounter.h new file mode 100644 index 00000000000..a82d9f2628c --- /dev/null +++ b/include/linux/pcounter.h @@ -0,0 +1,74 @@ +#ifndef __LINUX_PCOUNTER_H +#define __LINUX_PCOUNTER_H +/* + * Using a dynamic percpu 'int' variable has a cost : + * 1) Extra dereference + * Current per_cpu_ptr() implementation uses an array per 'percpu variable'. + * 2) memory cost of NR_CPUS*(32+sizeof(void *)) instead of num_possible_cpus()*4 + * + * This pcounter implementation is an abstraction to be able to use + * either a static or a dynamic per cpu variable. + * One dynamic per cpu variable gets a fast & cheap implementation, we can + * change pcounter implementation too. + */ +struct pcounter { +#ifdef CONFIG_SMP + void (*add)(struct pcounter *self, int inc); + int (*getval)(const struct pcounter *self, int cpu); + int *per_cpu_values; +#else + int val; +#endif +}; + +#ifdef CONFIG_SMP +#include <linux/percpu.h> + +#define DEFINE_PCOUNTER(NAME) \ +static DEFINE_PER_CPU(int, NAME##_pcounter_values); \ +static void NAME##_pcounter_add(struct pcounter *self, int val) \ +{ \ + __get_cpu_var(NAME##_pcounter_values) += val; \ +} \ +static int NAME##_pcounter_getval(const struct pcounter *self, int cpu) \ +{ \ + return per_cpu(NAME##_pcounter_values, cpu); \ +} \ + +#define PCOUNTER_MEMBER_INITIALIZER(NAME, MEMBER) \ + MEMBER = { \ + .add = NAME##_pcounter_add, \ + .getval = NAME##_pcounter_getval, \ + } + + +static inline void pcounter_add(struct pcounter *self, int inc) +{ + self->add(self, inc); +} + +extern int pcounter_getval(const struct pcounter *self); +extern int pcounter_alloc(struct pcounter *self); +extern void pcounter_free(struct pcounter *self); + + +#else /* CONFIG_SMP */ + +static inline void pcounter_add(struct pcounter *self, int inc) +{ + self->val += inc; +} + +static inline int pcounter_getval(const struct pcounter *self) +{ + return self->val; +} + +#define DEFINE_PCOUNTER(NAME) +#define PCOUNTER_MEMBER_INITIALIZER(NAME, MEMBER) +#define pcounter_alloc(self) 0 +#define pcounter_free(self) + +#endif /* CONFIG_SMP */ + +#endif /* __LINUX_PCOUNTER_H */ |
