On Mon, Dec 03, 2007 at 10:54:35PM +1100, Herbert Xu wrote:
>
> Hmm, wasn't someone else talking about a non-atomic version of atomic
> ops lately (i.e., atomic with respect to the local CPU only)? Perhaps
> this is the killer app for it :)
Never mind, we already have that in local_t and as Alexey correctly
points out, USER is still going to be the expensive variant with the
preempt_disable (well until BH gets threaded). So how about this patch?
Thanks,
--
Visit Openswan at http://www.openswan.org/
Email: Herbert Xu ~{PmV>HI~} <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
--
diff --git a/include/net/snmp.h b/include/net/snmp.h
index ea206bf..9444b54 100644
--- a/include/net/snmp.h
+++ b/include/net/snmp.h
@@ -23,6 +23,7 @@
#include <linux/cache.h>
#include <linux/snmp.h>
+#include <linux/smp.h>
/*
* Mibs are stored in array of unsigned long.
@@ -137,7 +138,10 @@ struct linux_mib {
#define SNMP_INC_STATS_OFFSET_BH(mib, field, offset) \
(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field + (offset)]++)
#define SNMP_INC_STATS_USER(mib, field) \
- (per_cpu_ptr(mib[1], raw_smp_processor_id())->mibs[field]++)
+ do { \
+ per_cpu_ptr(mib[1], get_cpu())->mibs[field]++; \
+ put_cpu(); \
+ } while (0)
#define SNMP_INC_STATS(mib, field) \
(per_cpu_ptr(mib[!in_softirq()], raw_smp_processor_id())->mibs[field]++)
#define SNMP_DEC_STATS(mib, field) \
@@ -145,6 +149,9 @@ struct linux_mib {
#define SNMP_ADD_STATS_BH(mib, field, addend) \
(per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field] += addend)
#define SNMP_ADD_STATS_USER(mib, field, addend) \
- (per_cpu_ptr(mib[1], raw_smp_processor_id())->mibs[field] += addend)
+ do { \
+ per_cpu_ptr(mib[1], get_cpu())->mibs[field] += addend; \
+ put_cpu(); \
+ } while (0)
#endif
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
