6:44 semtimedop(6062085, {{16, -1, 0}}, 1, {3, 0}) = -1 EAGAIN (Resource temporarily unavailable) –三秒差异
17:36:47 getrusage(RUSAGE_SELF, {ru_utime={125, 123978}, ru_stime={142, 731301}, ...}) = 0
17:36:47 getrusage(RUSAGE_SELF, {ru_utime={125, 123978}, ru_stime={142, 731301}, ...}) = 0
17:36:47 times({tms_utime=12512, tms_stime=14273, tms_cutime=0, tms_cstime=0}) = 645608755
17:36:47 times({tms_utime=12512, tms_stime=14273, tms_cutime=0, tms_cstime=0}) = 645608755
17:36:47 read(16, "MSA\0\2\0\10\0P\0\0\0\0\0\0\0\20?P\r\0\0\0\0\0\200\330\266\177\177\0\0"..., 80) = 80
17:36:47 read(16, "MSA\0\2\0\10\0P\0\0\0\0\0\0\0\20?P\r\0\0\0\0\0\200\330\266\177\177\0\0"..., 80) = 80
17:36:47 read(16, "MSA\0\2\0\10\0P\0\0\0\0\0\0\0\20?P\r\0\0\0\0\0\200\330\266\177\177\0\0"..., 80) = 80
17:36:47 read(16, "MSA\0\2\0\10\0P\0\0\0\0\0\0\0\20?P\r\0\0\0\0\0\200\330\266\177\177\0\0"..., 80) = 80
17:36:47 read(16, "MSA\0\2\0\10\0P\0\0\0\0\0\0\0\20?P\r\0\0\0\0\0\200\330\266\177\177\0\0"..., 80) = 80
17:36:47 read(16, "MSA\0\2\0\10\0P\0\0\0\0\0\0\0\20?P\r\0\0\0\0\0\200\330\266\177\177\0\0"..., 80) = 80
17:36:47 times({tms_utime=12512, tms_stime=14273, tms_cutime=0, tms_cstime=0}) = 645608756
17:36:47 times({tms_utime=12512, tms_stime=14273, tms_cutime=0, tms_cstime=0}) = 645608756
17:36:47 times({tms_utime=12512, tms_stime=14273, tms_cutime=0, tms_cstime=0}) = 645608756
17:36:47 times({tms_utime=12512, tms_stime=14273, tms_cutime=0, tms_cstime=0}) = 645608756
17:36:47 times({tms_utime=12512, tms_stime=14273, tms_cutime=0, tms_cstime=0}) = 645608756
17:36:47 semtimedop(6062085, {{16, -1, 0}}, 1, {3, 0}^C?
Process 21395 detached
从里面，我们可以看到ckpt的动作方式。
5、结论
Strace是Linux环境下的一个非常有用的工具。用好这个工具，可以让我们更加接近内核细节，丰富知识能力。