From d647b36a69bf0a630ebf981bde3c0651e2779e5e Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Thu, 20 Dec 2007 04:13:21 -0800 Subject: [PATCH] [SNMP]: Fix SNMP counters with PREEMPT The SNMP macros use raw_smp_processor_id() in process context which is illegal because the process may be preempted and then migrated to another CPU. This patch makes it use get_cpu/put_cpu to disable preemption. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- include/net/snmp.h | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/include/net/snmp.h b/include/net/snmp.h index 9c5793db637f..fbb66663a42c 100644 --- a/include/net/snmp.h +++ b/include/net/snmp.h @@ -23,6 +23,7 @@ #include #include +#include /* * Mibs are stored in array of unsigned long. @@ -135,14 +136,26 @@ struct linux_mib { #define SNMP_INC_STATS_BH(mib, field) \ (per_cpu_ptr(mib[0], raw_smp_processor_id())->mibs[field]++) #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]++) + do { \ + per_cpu_ptr(mib[!in_softirq()], get_cpu())->mibs[field]++; \ + put_cpu(); \ + } while (0) #define SNMP_DEC_STATS(mib, field) \ - (per_cpu_ptr(mib[!in_softirq()], raw_smp_processor_id())->mibs[field]--) + do { \ + per_cpu_ptr(mib[!in_softirq()], get_cpu())->mibs[field]--; \ + put_cpu(); \ + } while (0) #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 -- GitLab