Re: Memory Free up Failing on Solaris 8 - Off-topic

hmm,

free() doesn't do sbrk() with a negative to reduce the process space. So yes the space stays allocated.

Anjo.

• Original Message ----- To: "Multiple recipients of list ORACLE-L" <ORACLE-L_at_fatcity.com> Sent: Monday, February 03, 2003 7:58 AM

> Hi
>
> SITUATION - On a production APP Server having about 4000 Concurrent
application processes ,
> the memory allocated does NOT seem to be getting freed even though the
application program is issuing the respective call to Free the memory .
>
> Qs Any /etc/system parameters , OS patches which should help ?
>
> Qs Is our approach of using the pmap command Correct ?
> else what Command to find the "Private" memory taken up by a process would
be advisable ?
>
> Qs How to find the Total Amount of Swap Consumed ?
> [ We probably do NOT know how to interpret the vmstat output Correctly ,
> top/swap -s commands show an output Differing greatly from df -k output
for /tmp filesystem ]
>
> Qs Any Body has encountered such as situation before ?
>
>
> Configuration -
> Solaris 2.8
> Patch - Generic 108528-16 patch
> Machine SF15K
> CPUs = 36
> RAM = 96 GB
>
>
> We created a Small Sample C program which allocates & FREEs memory but
found that even after
> FREEing , the memory does NOT show as Freed in the pmap output . Is the
following approach correct ?
>
> DETAILS :-
>
> @@@@@@@@@@@@@@@@@ SAMPLE C PROGRAM @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
> #include <stdio.h>
> main()
> {
> char *abc = NULL ;
> int i = 0 ;
> for (i = 1; i < 10; i++){
> printf("allocating [%d] bytes\n", 10*1024*(i+1));
> abc = (char *)malloc(10*1024*(i+1));
> memset(abc, '\0', 10*1024*(i+1));
> getchar();
>
> free(abc);
> printf("Freeing [%d]\n", i);
> getchar();
> }
> exit() ;
> }
> @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
>
>
> RUN Output :-
>
> STEP 1 - allocating [20480] bytes
>
> pmap -x <PID of Above program process>
>
> Address Kbytes Resident Shared Private Permissions Mapped File
> 00010000 8 8 8 - read/exec a.out
> 00020000 8 8 - 8 read/write/exec a.out
> 00022000 24 24 - 24 read/write/exec [ heap ]
> FF280000 688 688 688 - read/exec libc.so.1
> FF33C000 32 32 - 32 read/write/exec libc.so.1
> FF370000 16 16 16 - read/exec libc_psr.so.1
> FF390000 8 8 8 - read/exec libdl.so.1
> FF3A0000 8 8 - 8 read/write/exec [ anon ]
> FF3B0000 152 152 152 - read/exec ld.so.1
> FF3E6000 8 8 - 8 read/write/exec ld.so.1
> FFBEC000 16 16 - 16 read/write/exec [ stack ]
> -------- ------ ------ ------ ------
> total Kb 968 968 872 96
>
> THE "Private" memory allocated by the [ heap ] is 24 K
>
> STEP 2 - Freeing the memory allocated in the above Step
>
> Freeing [1]
>
> pmap -x <PID of Above program process>
>
> Address Kbytes Resident Shared Private Permissions Mapped File
> 00022000 24 24 - 24 read/write/exec [ heap ]
>
> RESULT - THE "Private" memory allocated previously does NOT get Freed &
> [ heap ] continues to be 24 K
>
> STEP 3 -
> allocating [30720] bytes
>
> pmap -x <PID of Above Program process>
>
> Address Kbytes Resident Shared Private Permissions Mapped File
> 00022000 32 32 - 32 read/write/exec [ heap ]
>
> STEP 4 - Freeing the memory allocated in the above Step
> Freeing [2]
>
> pmap -x <PID of Above program process>
>
> Address Kbytes Resident Shared Private Permissions Mapped File
> 00022000 32 32 - 32 read/write/exec [ heap ]
>
> RESULT - THE "Private" memory allocated previously in Step 3 does NOT get
Freed &
> [ heap ] continues to be 32 K
>
> Thanks
>
> --
> Please see the official ORACLE-L FAQ: http://www.orafaq.net
> --
> Author: VIVEK_SHARMA
> INET: VIVEK_SHARMA_at_infosys.com
>
> Fat City Network Services -- 858-538-5051 http://www.fatcity.com
> San Diego, California -- Mailing list and web hosting services
> ---------------------------------------------------------------------
> To REMOVE yourself from this mailing list, send an E-Mail message
> to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
> the message BODY, include a line containing: UNSUB ORACLE-L
> (or the name of mailing list you want to be removed from). You may
> also send the HELP command for other information (like subscribing).
>

-- 
Please see the official ORACLE-L FAQ: http://www.orafaq.net
-- 
Author: Anjo Kolk
  INET: anjo_at_oraperf.com

Fat City Network Services    -- 858-538-5051 http://www.fatcity.com
San Diego, California        -- Mailing list and web hosting services
---------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).