| Message ID | 1394110536-4532-1-git-send-email-sergey.senozhatsky@gmail.com |
|---|---|
| State | Rejected, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, 2014-03-06 at 15:55 +0300, Sergey Senozhatsky wrote: > 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@gmail.com> > --- > include/net/snmp.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) I think you missed a lot of mails sent by Chrisoph Lameter recently... -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
From: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Date: Thu, 6 Mar 2014 15:55:36 +0300 > 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@gmail.com> This is a bug in the TCP code, if this code path can happen outside of software interrupts or BH protected sections, which it can as seen in this trace, it must use the non-_BH-postfixed versions of the SNMP counter bumps. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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)
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@gmail.com> --- include/net/snmp.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)