[PATCH] net: use raw_cpu ops in snmp stats bh

From: Sergey Senozhatsky
Date: Thu Mar 06 2014 - 07:59:31 EST


Commit a25982c15ae52 ("percpu: add preemption checks to __this_cpu
ops") added preemption checks to __this_cpu ops, which are used in
SNMP_INC_STATS_BH() and SNMP_ADD_STATS_BH(), resulting in following
warnings:

BUG: using __this_cpu_add() in preemptible [00000000] code: ssh/4661
caller is __this_cpu_preempt_check+0x2b/0x2d
CPU: 3 PID: 4661 Comm: ssh Not tainted 3.14.0-rc5-next-20140306-dbg-dirty #162
Hardware name: Acer Aspire 5741G /Aspire 5741G , BIOS V1.20 02/08/2011
0000000000000000 ffff880094939be0 ffffffff813b8305 0000000000000003
ffff880094939c00 ffffffff8121221f ffff88015130a8c0 0000000000000000
ffff880094939c38 ffffffff8121226b 635f736968745f5f 29286464615f7570
Call Trace:
[<ffffffff813b8305>] dump_stack+0x4e/0x7a
[<ffffffff8121221f>] check_preemption_disabled+0xce/0xdd
[<ffffffff8121226b>] __this_cpu_preempt_check+0x2b/0x2d
[<ffffffff81370b5a>] ? tcp_rearm_rto+0x9f/0xa1
[<ffffffff81373456>] tcp_event_new_data_sent+0x6d/0x91
[<ffffffff81374dc6>] tcp_write_xmit+0x3f1/0x935
[<ffffffff813754e4>] __tcp_push_pending_frames+0x28/0x82
[<ffffffff81368109>] tcp_push+0xcc/0x102
[<ffffffff8136a0c1>] tcp_sendmsg+0x8c5/0xb7a
[<ffffffff81207d59>] ? string.isra.6+0x3b/0x9f
[<ffffffff8138a10a>] inet_sendmsg+0x75/0xa0
[<ffffffff81320fb6>] sock_aio_write+0xe7/0xfe
[<ffffffff81207d59>] ? string.isra.6+0x3b/0x9f
[<ffffffff810e08ab>] do_sync_write+0x54/0x73
[<ffffffff810e0df7>] vfs_write+0xc6/0x17c
[<ffffffff810e1603>] SyS_write+0x44/0x78
[<ffffffff813be0a1>] tracesys+0xd4/0xd9

use raw_cpu_inc() and raw_cpu_add() instead of __this_cpu_inc()
and __this_cpu_add().

Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@xxxxxxxxx>
---
include/net/snmp.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/net/snmp.h b/include/net/snmp.h
index 36ab852..b549ad6 100644
--- a/include/net/snmp.h
+++ b/include/net/snmp.h
@@ -126,7 +126,7 @@ struct linux_xfrm_mib {
extern __typeof__(type) __percpu *name[SNMP_ARRAY_SZ]

#define SNMP_INC_STATS_BH(mib, field) \
- __this_cpu_inc(mib[0]->mibs[field])
+ raw_cpu_inc(mib[0]->mibs[field])

#define SNMP_INC_STATS_USER(mib, field) \
this_cpu_inc(mib[0]->mibs[field])
@@ -141,7 +141,7 @@ struct linux_xfrm_mib {
this_cpu_dec(mib[0]->mibs[field])

#define SNMP_ADD_STATS_BH(mib, field, addend) \
- __this_cpu_add(mib[0]->mibs[field], addend)
+ raw_cpu_add(mib[0]->mibs[field], addend)

#define SNMP_ADD_STATS_USER(mib, field, addend) \
this_cpu_add(mib[0]->mibs[field], addend)
--
1.9.0.382.g7f3562c

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/