2:09 a.m.
tree: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head: dfd71d381f7e1aa118e0368774aa05f5c4a48870
commit: 2b195850128f5bafde177b12489d9fa27962cc1e [5639/6402] tcp: add
tp->dup_ack_counter
config: x86_64-randconfig-r012-20200519 (attached as .config)
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project
135b877874fae96b4372c8a3fbfaa8ff44ff86e3)
reproduce:
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O
~/bin/make.cross
chmod +x ~/bin/make.cross
# install x86_64 cross compiling tool for clang build
# apt-get install binutils-x86-64-linux-gnu
git checkout 2b195850128f5bafde177b12489d9fa27962cc1e
# save the attached .config to linux build tree
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64
If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp(a)intel.com>
All warnings (new ones prefixed by >>, old ones prefixed by <<):
> net/ipv4/tcp_output.c:188:3: warning: result of comparison of
constant -1 with expression of type 'u8' (aka 'unsigned char') is always
false [-Wtautological-constant-out-of-range-compare]
NET_ADD_STATS(sock_net(sk),
LINUX_MIB_TCPACKCOMPRESSED,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/net/ip.h:293:41: note: expanded from macro 'NET_ADD_STATS'
#define NET_ADD_STATS(net, field, adnd) SNMP_ADD_STATS((net)->mib.net_statistics,
field, adnd)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/net/snmp.h:143:4: note: expanded from macro 'SNMP_ADD_STATS'
this_cpu_add(mib->mibs[field], addend)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/linux/percpu-defs.h:509:33: note: expanded from macro 'this_cpu_add'
#define this_cpu_add(pcp, val) __pcpu_size_call(this_cpu_add_, pcp, val)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
note: (skipping 1 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all)
<scratch space>:292:1: note: expanded from here
this_cpu_add_8
^
arch/x86/include/asm/percpu.h:492:35: note: expanded from macro 'this_cpu_add_8'
#define this_cpu_add_8(pcp, val) percpu_add_op(volatile, (pcp), val)
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/x86/include/asm/percpu.h:131:31: note: expanded from macro 'percpu_add_op'
((val) == 1 || (val) == -1)) ?
~~~~~ ^ ~~
1 warning generated.
vim +188 net/ipv4/tcp_output.c
^1da177e4c3f41 Linus Torvalds 2005-04-16 180
67edfef7863957 Andi Kleen 2009-07-21 181 /* Account for an ACK we sent.
*/
27cde44a259c38 Yuchung Cheng 2018-07-18 182 static inline void
tcp_event_ack_sent(struct sock *sk, unsigned int pkts,
27cde44a259c38 Yuchung Cheng 2018-07-18 183 u32 rcv_nxt)
^1da177e4c3f41 Linus Torvalds 2005-04-16 184 {
5d9f4262b7ea41 Eric Dumazet 2018-05-17 185 struct tcp_sock *tp =
tcp_sk(sk);
5d9f4262b7ea41 Eric Dumazet 2018-05-17 186
2b195850128f5b Eric Dumazet 2020-04-30 187 if
(unlikely(tp->compressed_ack)) {
200d95f4575934 Eric Dumazet 2018-05-17 @188 NET_ADD_STATS(sock_net(sk),
LINUX_MIB_TCPACKCOMPRESSED,
2b195850128f5b Eric Dumazet 2020-04-30 189 tp->compressed_ack);
2b195850128f5b Eric Dumazet 2020-04-30 190 tp->compressed_ack = 0;
5d9f4262b7ea41 Eric Dumazet 2018-05-17 191 if
(hrtimer_try_to_cancel(&tp->compressed_ack_timer) == 1)
5d9f4262b7ea41 Eric Dumazet 2018-05-17 192 __sock_put(sk);
5d9f4262b7ea41 Eric Dumazet 2018-05-17 193 }
27cde44a259c38 Yuchung Cheng 2018-07-18 194
27cde44a259c38 Yuchung Cheng 2018-07-18 195 if (unlikely(rcv_nxt !=
tp->rcv_nxt))
27cde44a259c38 Yuchung Cheng 2018-07-18 196 return; /* Special ACK sent by
DCTCP to reflect ECN */
463c84b97f2401 Arnaldo Carvalho de Melo 2005-08-09 197 tcp_dec_quickack_mode(sk,
pkts);
463c84b97f2401 Arnaldo Carvalho de Melo 2005-08-09 198 inet_csk_clear_xmit_timer(sk,
ICSK_TIME_DACK);
^1da177e4c3f41 Linus Torvalds 2005-04-16 199 }
^1da177e4c3f41 Linus Torvalds 2005-04-16 200
:::::: The code at line 188 was first introduced by commit
:::::: 200d95f4575934e49f872109cce18c5e72383eb8 tcp: add TCPAckCompressed SNMP counter
:::::: TO: Eric Dumazet <edumazet(a)google.com>
:::::: CC: David S. Miller <davem(a)davemloft.net>
---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org