Weird VMS return value

[jchien14]

Hey all, getting this in Python with psutil for process memory usage. (18120 has no parent process by the way).

>>> psutil.Process().memory_info()
pmem(rss=5033984L, vms=2569285632L)
>>> psutil.Process().pid
18146
>>> psutil.Process().ppid()
18120

When doing a vmmap though on the two processes, this is the result:

==== Summary for process 18146
ReadOnly portion of Libraries: Total=176.4M resident=0K(0%) swapped_out_or_unallocated=176.4M(100%)
Writable regions: Total=85.3M written=0K(0%) resident=0K(0%) swapped_out=0K(0%) unallocated=85.3M(100%)

                                VIRTUAL   REGION 
REGION TYPE                        SIZE    COUNT (non-coalesced) 
===========                     =======  ======= 
Activity Tracing                  2048K        2 
Kernel Alloc Once                    4K        2 
MALLOC guard page                   32K        7 
MALLOC metadata                    356K       10 
MALLOC_LARGE                      2752K        7         see MALLOC ZONE table below
MALLOC_LARGE metadata                4K        2         see MALLOC ZONE table below
MALLOC_SMALL                      32.0M        3         see MALLOC ZONE table below
MALLOC_SMALL (empty)              32.0M        3         see MALLOC ZONE table below
MALLOC_TINY                       8192K        6         see MALLOC ZONE table below
STACK GUARD                       56.0M        2 
Stack                             8192K        2 
__DATA                            8956K      161 
__LINKEDIT                        88.8M       21 
__TEXT                            87.6M      164 
__UNICODE                          552K        2 
shared memory                       12K        4 
===========                     =======  ======= 
TOTAL                            326.8M      382 

                                 VIRTUAL ALLOCATION      BYTES          REGION
MALLOC ZONE                         SIZE      COUNT  ALLOCATED  % FULL   COUNT
===========                      =======  =========  =========  ======  ======
DefaultMallocZone_0x1005db000      74.7M       5398      4456K      5%      16
GFXMallocZone_0x10060c000             0K          0         0K               0
===========                      =======  =========  =========  ======  ======
TOTAL                              74.7M       5398      4456K      5

==== Summary for process 18120
ReadOnly portion of Libraries: Total=105.2M resident=0K(0%) swapped_out_or_unallocated=105.2M(100%)
Writable regions: Total=87.9M written=0K(0%) resident=0K(0%) swapped_out=0K(0%) unallocated=87.9M(100%)

                                VIRTUAL   REGION 
REGION TYPE                        SIZE    COUNT (non-coalesced) 
===========                     =======  ======= 
Activity Tracing                  2048K        2 
Kernel Alloc Once                    4K        2 
MALLOC guard page                   16K        4 
MALLOC metadata                    180K        6 
MALLOC_LARGE                       768K        2         see MALLOC ZONE table below
MALLOC_LARGE (empty)              1220K        3         see MALLOC ZONE table below
MALLOC_LARGE metadata                4K        2         see MALLOC ZONE table below
MALLOC_SMALL                      64.0M        3         see MALLOC ZONE table below
MALLOC_TINY                       8192K        6         see MALLOC ZONE table below
STACK GUARD                       56.0M        2 
Stack                             8192K        2 
VM_ALLOCATE                       3584K       12 
__DATA                            3640K       80 
__LINKEDIT                        88.1M       31 
__TEXT                            17.0M       78 
__UNICODE                          552K        2 
shared memory                       12K        4 
===========                     =======  ======= 
TOTAL                            252.9M      224 

                                 VIRTUAL ALLOCATION      BYTES          REGION
MALLOC ZONE                         SIZE      COUNT  ALLOCATED  % FULL   COUNT
===========                      =======  =========  =========  ======  ======
DefaultMallocZone_0x10a615000      72.8M       4404      3057K      4%       9

This is the result in Activity Monitor: http://i.imgur.com/RGOHBZT.png

Any ideas why psutil is reporting over 2GB for Virtual Memory? Is this a bug? This is on OSX 10.11, 64-bit Python.

[jchien14]

May be related to #685 ?

[giampaolo]

Sorry for the huge delay in responding. I'm not sure why VMS is so high on OSX but there is a test which compares VMS result with ps and they match 100%:

psutil/psutil/tests/test_posix.py

Line 109 in b360dcd

def test_vsz_memory(self):

I also see over 2GB memory for basically every process, which is definitively weird (see VSZ column in ps output below). I'm confused.

osx-elcaptain:psutil root# ps aux
USER              PID  %CPU %MEM      VSZ    RSS   TT  STAT STARTED      TIME COMMAND
root               73   3.6  0.2  2486736  10404   ??  Ss   18Oct16   0:12.27 /usr/libexec/opendirectory
root               98   1.0  0.0  2449364   1324   ??  Ss   18Oct16   0:07.65 /usr/sbin/notifyd
vagrant         39635   0.9  0.0  2451904   1620   ??  S    26Oct16   0:02.07 sshd: vagrant@ttys001 
_securityagent    277   0.8  0.9  2569220  39760   ??  Us   18Oct16   6:25.46 /System/Library/Frameworks
root                1   0.4  0.1  2468540   6128   ??  Ss   18Oct16   1:44.82 /sbin/launchd
_windowserver     161   0.2  0.9  2653096  37320   ??  Ss   18Oct16   3:30.38 /System/Library/Frameworks
root            39686   0.1  0.0  2444656   1284 s001  S    26Oct16   0:00.41 -sh
root            39684   0.0  0.1  2444408   3008 s001  S    26Oct16   0:00.03 sudo su -
vagrant         39636   0.0  0.0  2444652   1372 s001  Ss   26Oct16   0:00.03 -bash
...

[no-response]

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