以下脚本用户跟踪redis的主定时器事件serverCron的每次耗时

    1. # sudo stap serverCronMs.stp
    4. probe begin {
    5.   printf("Start...\n");
    6. }
    8. global enterMs
    11. probe process("/data/redis/src/redis-server").function("serverCron").call {
    12.     enterMs = gettimeofday_ms();
    13. }
    15. probe process("/data/redis/src/redis-server").function("serverCron").return {
    16.     nowMs = gettimeofday_ms();
    17.     printf("serverCron enterMs:%\d, returnMs: %d, elapsed %ldms\n",enterMs, nowMs, nowMs - enterMs);
    18. }

    输出如下:

    1. kuiper@ubuntu-v64:/data$ sudo stap serverCronMs.stp 
    2. Start...
    3. serverCron enterMs:1635072250022, returnMs: 1635072250022, elapsed 0ms
    4. serverCron enterMs:1635072250123, returnMs: 1635072250123, elapsed 0ms
    5. serverCron enterMs:1635072250224, returnMs: 1635072250224, elapsed 0ms
    6. serverCron enterMs:1635072250325, returnMs: 1635072250325, elapsed 0ms
    7. serverCron enterMs:1635072250426, returnMs: 1635072250426, elapsed 0ms
    8. serverCron enterMs:1635072250527, returnMs: 1635072250527, elapsed 0ms
    9. serverCron enterMs:1635072250628, returnMs: 1635072250628, elapsed 0ms
    10. serverCron enterMs:1635072250728, returnMs: 1635072250728, elapsed 0ms
    11. serverCron enterMs:1635072250829, returnMs: 1635072250829, elapsed 0ms
    12. serverCron enterMs:1635072250929, returnMs: 1635072250929, elapsed 0ms
    13. serverCron enterMs:1635072251030, returnMs: 1635072251030, elapsed 0ms
    14. serverCron enterMs:1635072251131, returnMs: 1635072251131, elapsed 0ms
    15. serverCron enterMs:1635072251232, returnMs: 1635072251232, elapsed 0ms
    16. serverCron enterMs:1635072251333, returnMs: 1635072251333, elapsed 0ms
    17. serverCron enterMs:1635072251434, returnMs: 1635072251435, elapsed 1ms
    18. serverCron enterMs:1635072251535, returnMs: 1635072251535, elapsed 0ms
    19. serverCron enterMs:1635072251635, returnMs: 1635072251636, elapsed 1ms

    直方图每秒打印1次, 每次刚好10次serverCrop， 具体的分布情况 单位微秒

    2. probe begin {
    3.   printf("Start...\n");
    4. }
    6. global enterMs
    7. global sends
    10. probe process("/data/redis/src/redis-server").function("serverCron").call {
    11.     //printf("******************************************************************\n");
    12.     //enterMs = gettimeofday_us();
    13. }
    15. probe process("/data/redis/src/redis-server").function("serverCron").return {
    16.     // nowMs = gettimeofday_us();
    17.     // print_ubacktrace();
    18.     // printf("%s\n", thread_indent(4));
    19.     // printf("serverCron enterMs:%\d, returnMs: %d, elapsed %ldms\n",enterMs, nowMs, nowMs - enterMs);
    20.     sends <<< gettimeofday_us() - @entry(gettimeofday_us())
    21. }
    24. probe timer.s(1) {
    25.     print(@hist_log(sends));
    26.     delete sends
    27. }

    输出: 

    1. value |-------------------------------------------------- count
    2.    16 |                                                   0
    3.    32 |                                                   0
    4.    64 |@@                                                 2
    5.   128 |@                                                  1
    6.   256 |@@@@@@                                             6
    7.   512 |@                                                  1
    8.  1024 |                                                   0
    9.  2048 |                                                   0
    11. value |-------------------------------------------------- count
    12.    16 |                                                   0
    13.    32 |                                                   0
    14.    64 |@@@@@                                              5
    15.   128 |@                                                  1
    16.   256 |@@@@                                               4
    17.   512 |                                                   0
    18.  1024 |                                                   0
    20. value |-------------------------------------------------- count
    21.     8 |                                                   0
    22.    16 |                                                   0
    23.    32 |@@@@                                               4
    24.    64 |                                                   0
    25.   128 |                                                   0
    26.   256 |@@@@@                                              5
    27.   512 |@                                                  1
    28.  1024 |                                                   0
    29.  2048 |                                                   0