$ sudo strace -qq -f -e madvise,brk -p 1234
[pid 2323] brk(NULL) = 0x1092000
[pid 2323] brk(NULL) = 0x1092000
[pid 2323] brk(0x10b3000) = 0x10b3000
[pid 2323] brk(NULL) = 0x10b3000
[pid 2323] brk(NULL) = 0x10b3000
[pid 2323] brk(NULL) = 0x56538b58b000
[pid 2323] brk(NULL) = 0x56538b58b000
[pid 2323] brk(0x56538b5ac000) = 0x56538b5ac000
[pid 2323] brk(NULL) = 0x56538b5ac000
[pid 12568] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=2323, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
[pid 2367] brk(NULL) = 0xff2000
[pid 2367] brk(NULL) = 0xff2000
[pid 2367] brk(0x1013000) = 0x1013000
[pid 2367] brk(NULL) = 0x1013000
[pid 2367] brk(NULL) = 0x1013000
[pid 2367] brk(NULL) = 0x55d9c9efb000
[pid 2367] brk(NULL) = 0x55d9c9efb000
[pid 2367] brk(0x55d9c9f1c000) = 0x55d9c9f1c000
[pid 2367] brk(NULL) = 0x55d9c9f1c000
[pid 12536] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=2367, si_uid=0, si_status=0, si_utime=0, si_stime=0} ---
[pid 2414] brk(NULL) = 0x128b000
[pid 2414] brk(NULL) = 0x128b000
[pid 2414] brk(0x12ac000) = 0x12ac000
[pid 2414] brk(NULL) = 0x12ac000
[pid 2414] brk(NULL) = 0x12ac000
[pid 2414] brk(NULL) = 0x564bb31a3000
[pid 2414] brk(NULL) = 0x564bb31a3000
[pid 2414] brk(0x564bb31c4000) = 0x564bb31c4000
[pid 2414] brk(NULL) = 0x564bb31c4000
[pid 12530] --- SIGCHLD {si_signo=SIGCHLD, si_code=CLD_EXITED, si_pid=2414, si_uid=0, si_status=0, si_utime=0, si_stime=0} --
The brk syscall call change too much, and the value seem not match the maps file.
sudo cat /proc/1234/maps | grep heap
01a73000-01a94000 rw-p 00000000 00:00 0 [heap]