RE: Memory Free up Failing on Solaris 8 - Off-topic
Anjo response is correct. Try running truss against your executable. You will
see that brk is called for allocating memory. The way I understand it is,
brk/sbrk is the system call which allocates/deallocates memory and malloc is
the user mode library which internally calls brk/sbrk. I don't think free
actually releases the memory back to the OS, but may reuse the memory for
another request. Run the attached program and check the output. After you free
the memory, the next malloc allocates the same memory which has been freed.
Output of truss snipped on your program
=
fstat(3, 0xFFBEEFAC)= 0
mmap(0x, 8192, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0xFF31
mmap(0x, 16384, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0xFF30
close(3)= 0
munmap(0xFF31, 8192)= 0
ioctl(1, TCGETA, 0xFFBEEBA4)= 0
allocating [20480] bytes
write(1, a l l o c a t i n g [.., 25) = 25
brk(0x00020ED0) = 0
brk(0x00026ED0) = 0
ioctl(0, TCGETA, 0xFFBEF7CC)= 0
read(0, \n, 1024) = 1
Freeing [1]
write(1, F r e e i n g [ 1 ]\n, 12)= 12
read(0, 0xFF2BF634, 1024) (sleeping...)
read(0, \n, 1024) = 1
allocating [30720] bytes
write(1, a l l o c a t i n g [.., 25) = 25
brk(0x00026ED0) = 0
brk(0x00028ED0) = 0
read(0, 0xFF2BF634, 1024) (sleeping...)
read(0, \n, 1024) = 1
Freeing [2]
write(1, F r e e i n g [ 2 ]\n, 12)= 12
read(0, 0xFF2BF634, 1024) (sleeping...)
read(0, \n, 1024) = 1
allocating [40960] bytes
write(1, a l l o c a t i n g [.., 25) = 25
brk(0x00028ED0) = 0
brk(0x0002CED0) = 0
read(0, 0xFF2BF634, 1024) (sleeping...)
read(0, \n, 1024) = 1
Freeing [3]
write(1, F r e e i n g [ 3 ]\n, 12)= 12
read(0, 0xFF2BF634, 1024) (sleeping...)
#include stdio.h
#include malloc.h
#include string.h
main()
{
char *loc1;
char *loc2;
printf(Allocating [%d] bytes\n, 10*1024);
loc1 = (char *) malloc(10*1024);
printf(Address : %x\n,loc1);
printf(Allocating [%d] bytes\n, 10*1024);
loc2 = (char *) malloc(10*1024);
printf(Address : %x\n,loc2);
free(loc1);
free(loc2);
printf(Allocating [%d] bytes\n, 10*1024);
loc1 = (char *) malloc(10*1024);
printf(Address : %x\n,loc1);
printf(Allocating [%d] bytes\n, 10*1024);
loc2 = (char *) malloc(10*1024);
printf(Address : %x\n,loc2);
free(loc1);
free(loc2);
printf(Allocating [%d] bytes\n, 10*1024);
loc1 = (char *) malloc(10*1024);
printf(Address : %x\n,loc2);
free(loc1);
}
Regards,
Denny
Quoting VIVEK_SHARMA [EMAIL PROTECTED]:
Hi
brk, sbrk functions are used for DATA segments and we have problem with
HEAP. Malloc allocates space onto heap and not in DATA segment.
Seemingly the man page imply that it should not be used in conjunction
with malloc, calloc ,
that we are using.
Pasting from man pages :-
USAGE
The behavior of brk() and sbrk() is unspecified if an appli-
cation also uses any other memory functions (such as
malloc(3C), mmap(2), free(3C)).
Qs. Is any alternative function which can be used OR am i missing
something ?
Thanks
-Original Message-
Sent: Monday, February 03, 2003 1:19 PM
To: Multiple recipients of list ORACLE-L
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 [EMAIL PROTECTED]
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
Re: Memory Free up Failing on Solaris 8 - Off-topic
Thanks Denny :-)
I remember writing a tool to prove this point in 1992, it was called ms
(memory status), it showed all memory segments (heap, text, shared
memory, shared objects, data segment etc). It worked the same as ps, but
then for memory. I had enough of explaining all the time that the SZ
column in ps contained the shared memory pages for the SGA also.
Anjo.
Denny Koovakattu wrote:
Anjo response is correct. Try running truss against your executable. You will
see that brk is called for allocating memory. The way I understand it is,
brk/sbrk is the system call which allocates/deallocates memory and malloc is
the user mode library which internally calls brk/sbrk. I don't think free
actually releases the memory back to the OS, but may reuse the memory for
another request. Run the attached program and check the output. After you free
the memory, the next malloc allocates the same memory which has been freed.
Output of truss snipped on your program
=
fstat(3, 0xFFBEEFAC)= 0
mmap(0x, 8192, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0xFF31
mmap(0x, 16384, PROT_READ|PROT_EXEC, MAP_PRIVATE, 3, 0) = 0xFF30
close(3)= 0
munmap(0xFF31, 8192)= 0
ioctl(1, TCGETA, 0xFFBEEBA4)= 0
allocating [20480] bytes
write(1, a l l o c a t i n g [.., 25) = 25
brk(0x00020ED0) = 0
brk(0x00026ED0) = 0
ioctl(0, TCGETA, 0xFFBEF7CC)= 0
read(0, \n, 1024) = 1
Freeing [1]
write(1, F r e e i n g [ 1 ]\n, 12)= 12
read(0, 0xFF2BF634, 1024) (sleeping...)
read(0, \n, 1024) = 1
allocating [30720] bytes
write(1, a l l o c a t i n g [.., 25) = 25
brk(0x00026ED0) = 0
brk(0x00028ED0) = 0
read(0, 0xFF2BF634, 1024) (sleeping...)
read(0, \n, 1024) = 1
Freeing [2]
write(1, F r e e i n g [ 2 ]\n, 12)= 12
read(0, 0xFF2BF634, 1024) (sleeping...)
read(0, \n, 1024) = 1
allocating [40960] bytes
write(1, a l l o c a t i n g [.., 25) = 25
brk(0x00028ED0) = 0
brk(0x0002CED0) = 0
read(0, 0xFF2BF634, 1024) (sleeping...)
read(0, \n, 1024) = 1
Freeing [3]
write(1, F r e e i n g [ 3 ]\n, 12)= 12
read(0, 0xFF2BF634, 1024) (sleeping...)
#include stdio.h
#include malloc.h
#include string.h
main()
{
char *loc1;
char *loc2;
printf(Allocating [%d] bytes\n, 10*1024);
loc1 = (char *) malloc(10*1024);
printf(Address : %x\n,loc1);
printf(Allocating [%d] bytes\n, 10*1024);
loc2 = (char *) malloc(10*1024);
printf(Address : %x\n,loc2);
free(loc1);
free(loc2);
printf(Allocating [%d] bytes\n, 10*1024);
loc1 = (char *) malloc(10*1024);
printf(Address : %x\n,loc1);
printf(Allocating [%d] bytes\n, 10*1024);
loc2 = (char *) malloc(10*1024);
printf(Address : %x\n,loc2);
free(loc1);
free(loc2);
printf(Allocating [%d] bytes\n, 10*1024);
loc1 = (char *) malloc(10*1024);
printf(Address : %x\n,loc2);
free(loc1);
}
Regards,
Denny
Quoting VIVEK_SHARMA [EMAIL PROTECTED]:
Hi
brk, sbrk functions are used for DATA segments and we have problem with
HEAP. Malloc allocates space onto heap and not in DATA segment.
Seemingly the man page imply that it should not be used in conjunction
with malloc, calloc ,
that we are using.
Pasting from man pages :-
USAGE
The behavior of brk() and sbrk() is unspecified if an appli-
cation also uses any other memory functions (such as
malloc(3C), mmap(2), free(3C)).
Qs. Is any alternative function which can be used OR am i missing
something ?
Thanks
-Original Message-
Sent: Monday, February 03, 2003 1:19 PM
To: Multiple recipients of list ORACLE-L
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 [EMAIL PROTECTED]
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
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 [EMAIL PROTECTED]
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
0001 8 8 8 - read/exec a.out
0002 8 8 - 8 read/write/exec a.out
00022000 24 24 - 24 read/write/exec [ heap ]
FF28 688 688 688 - read/exec libc.so.1
FF33C000 32 32 - 32 read/write/exec libc.so.1
FF37 16 16 16 - read/exec libc_psr.so.1
FF39 8 8 8 - read/exec libdl.so.1
FF3A 8 8 - 8 read/write/exec [ anon ]
FF3B 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: [EMAIL PROTECTED]
Fat City Network Services-- 858-538-5051 http://www.fatcity.com
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Author: Anjo Kolk
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RE: Memory Free up Failing on Solaris 8 - Off-topic
Hi
brk, sbrk functions are used for DATA segments and we have problem with HEAP. Malloc
allocates space onto heap and not in DATA segment.
Seemingly the man page imply that it should not be used in conjunction with malloc,
calloc ,
that we are using.
Pasting from man pages :-
USAGE
The behavior of brk() and sbrk() is unspecified if an appli-
cation also uses any other memory functions (such as
malloc(3C), mmap(2), free(3C)).
Qs. Is any alternative function which can be used OR am i missing something ?
Thanks
-Original Message-
Sent: Monday, February 03, 2003 1:19 PM
To: Multiple recipients of list ORACLE-L
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 [EMAIL PROTECTED]
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
0001 8 8 8 - read/exec a.out
0002 8 8 - 8 read/write/exec a.out
00022000 24 24 - 24 read/write/exec [ heap ]
FF28 688 688 688 - read/exec libc.so.1
FF33C000 32 32 - 32 read/write/exec libc.so.1
FF37 16 16 16 - read/exec libc_psr.so.1
FF39 8 8 8 - read/exec libdl.so.1
FF3A 8 8 - 8 read/write/exec [ anon ]
FF3B 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: [EMAIL PROTECTED]
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: [EMAIL PROTECTED] (note
