测量互斥争用/解释互斥输出

Measuring mutex contention / interpreting mutrace output

本文关键字:输出 解释 争用 测量      更新时间:2023-10-16

我试图用mutrace测量程序中的互斥争用,但在如何使用它输出的报告方面遇到了困难。

mutrace: Showing statistics for process test (PID: 5924).
mutrace: 1223 mutexes used.
Mutex #362 (0x0x1a23750) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_mutex_init+0x1b2) [0x7fb6b14129b4]
        ./test() [0x500042]
Mutex #390 (0x0x1a23ac0) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_mutex_init+0x1b2) [0x7fb6b14129b4]
        ./test() [0x500042]
Mutex #965 (0x0x1a3a600) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_mutex_init+0x1b2) [0x7fb6b14129b4]
        ./test() [0x500042]
Mutex #502 (0x0x1abbc90) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_mutex_init+0x1b2) [0x7fb6b14129b4]
        ./test() [0x500042]
Mutex #241 (0x0x7fb6af9019c0) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_mutex_lock+0x116) [0x7fb6b1412da6]
        /lib/libgcc_s.so.1(_Unwind_Find_FDE+0x2a) [0x7fb6af6fe3ea]
        [(nil)]
Mutex #704 (0x0x7fb6afe85020) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_mutex_lock+0x116) [0x7fb6b1412da6]
        /usr/lib/libstdc++.so.6(_ZNSt6localeC1Ev+0x2f) [0x7fb6afbf021f]
Mutex #452 (0x0x1a240b0) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_mutex_init+0x1b2) [0x7fb6b14129b4]
        ./test() [0x500042]
Mutex #981 (0x0x1a3a770) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_mutex_init+0x1b2) [0x7fb6b14129b4]
        ./test() [0x500042]
Mutex #626 (0x0x73daa8) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_mutex_init+0x1b2) [0x7fb6b14129b4]
        ./test(_ZN7threads5mutexC2Eb+0x5e) [0x50675e]
Mutex #801 (0x0x1ab6798) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_mutex_init+0x1b2) [0x7fb6b14129b4]
        ./test(_ZN7threads5mutexC1Eb+0x5e) [0x50643e]
mutrace: Showing 10 mutexes in order of (write) contention count:
 Mutex #   Locked  Changed    Cont. cont.Time[ms] tot.Time[ms] avg.Time[ms] Flags
     362   517216   163871    70638       619.184      138.933        0.000 M-.--.
     390   180589    61197    31681      5926.827      463.255        0.003 M-.--.
     965    38679    24052    10646       661.639      718.836        0.019 M-.--.
     502    35394    19012     1540       153.286      134.116        0.004 M-.--.
     241     3481     2715     1378       135.624        1.189        0.000 M-.--.
     704    20902     3879       70         0.594        6.702        0.000 M-.--.
     452      892      158       49        21.401      125.918        0.141 M-.--.
     981     2369     2361       12         0.229       12.984        0.005 M-.--.
     626      598      270        4         0.139        8.417        0.014 Mx.r-.
     801      125        2        1         0.012        0.270        0.002 Mx.r-.
     ...      ...      ...      ...           ...          ...          ... ||||||
                                                                            /|||||
          Object:                                      M = Mutex, W = RWLock /||||
           State:                                  x = dead, ! = inconsistent /|||
             Use:                                  R = used in realtime thread /||
      Mutex Type:                   r = RECURSIVE, e = ERRORCHECK, a = ADAPTIVE /|
  Mutex Protocol:                                       i = INHERIT, p = PROTECT /
     RWLock Kind:  r = PREFER_READER, w = PREFER_WRITER, W = PREFER_WRITER_NONREC 
mutrace: Note that rwlocks are shown as two lines: write locks then read locks.
mutrace: Note that the flags column R is only valid in --track-rt mode!
mutrace: 275 condition variables used.
Condvar #235 (0x0x7fb6a039d5c8) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_cond_init+0x120) [0x7fb6b14134be]
        ./test(_ZN7threads4condC1Ev+0x17) [0x5051b7]
Condvar #153 (0x0x7fb6a8259978) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_cond_init+0x120) [0x7fb6b14134be]
        ./test(_ZN7threads4condC1Ev+0x17) [0x5051b7]
Condvar #42 (0x0x7fb6a03e8188) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_cond_init+0x120) [0x7fb6b14134be]
        ./test(_ZN7threads4condC1Ev+0x17) [0x5051b7]
Condvar #222 (0x0x7fb6a019b7c8) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_cond_init+0x120) [0x7fb6b14134be]
        ./test(_ZN7threads4condC1Ev+0x17) [0x5051b7]
Condvar #118 (0x0x7fb6a0223ca8) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_cond_init+0x120) [0x7fb6b14134be]
        ./test(_ZN7threads4condC1Ev+0x17) [0x5051b7]
Condvar #8 (0x0x7fb6a820d748) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_cond_init+0x120) [0x7fb6b14134be]
        ./test(_ZN7threads4condC1Ev+0x17) [0x5051b7]
Condvar #171 (0x0x7fb69c04d9d8) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_cond_init+0x120) [0x7fb6b14134be]
        ./test(_ZN7threads4condC1Ev+0x17) [0x5051b7]
Condvar #0 (0x0x7fb69c22a2e8) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_cond_init+0x120) [0x7fb6b14134be]
        ./test(_ZN7threads4condC1Ev+0x17) [0x5051b7]
Condvar #75 (0x0x7fb6a81a65f8) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_cond_init+0x120) [0x7fb6b14134be]
        ./test(_ZN7threads4condC1Ev+0x17) [0x5051b7]
Condvar #142 (0x0x7fb6a001c308) first referenced by:
        /usr/local/lib/libmutrace.so(pthread_cond_init+0x120) [0x7fb6b14134be]
        ./test(_ZN7threads4condC1Ev+0x17) [0x5051b7]
mutrace: Showing 10 condition variables in order of wait contention count:
  Cond #    Waits  Signals    Cont. tot.Time[ms] cont.Time[ms] avg.Time[ms] Flags
     235      271        0        0     1370.469         0.000        0.000     x.
     153      190        0        0      960.142         0.000        0.000     x.
      42       65        0        0      328.264         0.000        0.000     x.
     222       52        0        0      262.584         0.000        0.000     x.
     118       51        0        0      261.869         0.000        0.000     x.
       8       48        0        0      242.422         0.000        0.000     x.
     171       41        0        0      207.044         0.000        0.000     x.
       0       38        0        0      191.881         0.000        0.000     x.
      75       37        0        0      186.835         0.000        0.000     x.
     142       35        0        0      176.704         0.000        0.000     x.
     ...      ...      ...      ...          ...           ...          ...     ||
                                                                                /|
           State:                                     x = dead, ! = inconsistent /
             Use:                                     R = used in realtime thread 
mutrace: Note that the flags column R is only valid in --track-rt mode!
mutrace: Total runtime is 3701.228 ms.
mutrace: Results for SMP with 8 processors.

我似乎肯定有互斥争用问题,但我不知道如何将其与源代码关联起来。我希望能有更好的回溯。

该可执行文件是根据mutrace的网站使用-rdynamic编译的(还有-gdb)。

我在stackoverflow上发现了mutrace,所以希望有一些有经验的人!

谢谢。

从未使用过mutrace,但地址到符号的转换可以使用:地址2线

例如:

addr2line -e sysopview 0x5051b7

在本例中,"sysopview"是指向地址所在二进制文件的路径,0x5051b7是示例地址。Addr2line将发出它认为应该映射到它的名称。也可以使用回溯。

示例输出:

folkert@belle:~/Projects/entropybroker/trunk$addr2line-e/entropy_broker 0x0000000000406968/home/folkert/Projects/entropybroker/ttrunk/handle_client.cpp:761

在本例中,地址0x406968映射到文件handle_client.cpp的761行。

在Debian上,这个程序可以在"binutils"包中找到。

我在realease构建中保留了调试标志,所以-g-ddb-rdynamic都被启用了。我想这会没事的。在切换回我的调试版本后,删除-O2使回溯更加有用。还是有伤,但好多了。

我发现所有争用率最高的互斥体都被用于gnutls使用的gcrypt-lib中的同步。可能需要进行实验,看看回到openssl是否会改进它,或者cyassl!

谢谢。