1 ，test 代码见： https://go.dev/play/p/2xa_tqKsjWH

2 ，使用命令 strace -e 'signal=!all' -e '!rt_sigreturn,rt_sigaction,rt_sigprocmask,futex' ./test 得到

execve("./test", ["./test"], 0x7fff95cd9970 /* 21 vars */) = 0 arch_prctl(ARCH_SET_FS, 0x4cba70) = 0 sched_getaffinity(0, 8192, [0, 1, 2, 3, 4, 5, 6, 7]) = 32 openat(AT_FDCWD, "/sys/kernel/mm/transparent_hugepage/hpage_pmd_size", O_RDONLY) = 3 read(3, "2097152\n", 20) = 8 close(3) = 0 mmap(NULL, 262144, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0b9870f000 mmap(NULL, 131072, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0b986ef000 mmap(NULL, 1048576, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0b985ef000 mmap(NULL, 8388608, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0b97def000 mmap(NULL, 67108864, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0b93def000 mmap(NULL, 536870912, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0b73def000 mmap(0xc000000000, 67108864, PROT_NONE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xc000000000 mmap(0xc000000000, 67108864, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xc000000000 mmap(NULL, 33554432, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0b71def000 mmap(NULL, 2165776, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0b71bde000 mmap(0x7f0b986ef000, 131072, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f0b986ef000 mmap(0x7f0b9866f000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f0b9866f000 mmap(0x7f0b981f5000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f0b981f5000 mmap(0x7f0b95e1f000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f0b95e1f000 mmap(0x7f0b83f6f000, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f0b83f6f000 mmap(NULL, 1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0b71ade000 mmap(NULL, 65536, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0b71ace000 mmap(NULL, 65536, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f0b71abe000 sigaltstack(NULL, {ss_sp=NULL, ss_flags=SS_DISABLE, ss_size=0}) = 0 sigaltstack({ss_sp=0xc000002000, ss_flags=0, ss_size=32768}, NULL) = 0 gettid() = 3689 clone(child_stack=0xc000050000, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS, tls=0xc000040090) = 3690 clone(child_stack=0xc000052000, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS, tls=0xc000040490) = 3691 clone(child_stack=0xc00004c000, flags=CLONE_VM|CLONE_FS|CLONE_FILES|CLONE_SIGHAND|CLONE_THREAD|CLONE_SYSVSEM|CLONE_SETTLS, tls=0xc000040890) = 3693 write(2, "0xc00003c768", 120xc00003c768) = 12 

3 ，使用pmap -p 3689得到

0000000000400000 380K r-x-- /root/logs/test 000000000045f000 420K r---- /root/logs/test 00000000004c8000 16K rw--- /root/logs/test 00000000004cc000 200K rw--- [ anon ] 000000c000000000 65536K rw--- [ anon ] 00007f0b71a7e000 36292K rw--- [ anon ] 00007f0b73def000 263680K ----- [ anon ] 00007f0b83f6f000 4K rw--- [ anon ] 00007f0b83f70000 293564K ----- [ anon ] 00007f0b95e1f000 4K rw--- [ anon ] 00007f0b95e20000 36692K ----- [ anon ] 00007f0b981f5000 4K rw--- [ anon ] 00007f0b981f6000 4580K ----- [ anon ] 00007f0b9866f000 4K rw--- [ anon ] 00007f0b98670000 508K ----- [ anon ] 00007f0b986ef000 384K rw--- [ anon ] 00007ffdc654c000 132K rw--- [ stack ] 00007ffdc65a0000 12K r---- [ anon ] 00007ffdc65a3000 8K r-x-- [ anon ] 

我发现 2 个令人疑惑的地方，希望有大佬能指点：

1. 地址 7f0b986ef000 处，mmap 调用明明只申请了 128K 内存，怎么 pmap 命令却显示此处有 384K 内存。
2. pmap 显示地址 7f0b71a7e000 处的内存有 36292K ，这个内存地址是如何产生的？ starce 跟踪到的 mmap 调用并没有看到这个地址。