There are smarter people than me that can go into better detail, but I'll give it a shot. All the memory allocators you're usually going to see grow your address space using brk(1)/sbrk(1). They generally don't shrink the address space back down.
If you really need the address space to shrink (the common solution is just to let those pages get pushed out to the VM), try mmap() on a temporary file (or /dev/zero, but I donno if that works on solaris) and allocate memory out of that. When you're done with that, just unmap the file and the address space is freed. GNU malloc does this in certain situations. On Mon, Feb 25, 2008 at 1:33 AM, LiJIan <[EMAIL PROTECTED]> wrote: > Hi, > In performance test, my application (multi-thread programme) expriences a > memory consumption peak because there are at most e.g. 100 clients > communicate with it. My question is, why after all clients exit, when > application has noting to do, according to result of tool "pstack" or "pmap", > my application still occupy a big amount of memory ? > > My application use libmtmalloc.so.1 for memory allocation. > > I found description "After free() is executed, this space is made available > for further allocation by the application, though not returned to the > system. Memory is returned to the system only upon termination of the > application" > in the second paragraph of "malloc" man page; and description "After > free() is performed this space is available for further allocation" in the > thrid paragraph of "mtmalloc" man page. > > According to the descriptions, it seems "mtmalloc" is exactly different from > "malloc", and if using mtmalloc, after "free()" the consumed memory is > returned to system immediately, since in man page of "mtmalloc" it doesn't > emphasize the memory is not returned to system after "free()" is called until > application termination. Right ? > > But in our performance test we found "mtmalloc" has the same behaviour with > "malloc". > > BR/LiJian > > > -- > This message posted from opensolaris.org > _______________________________________________ > dtrace-discuss mailing list > [email protected] > -- H. Lally Singh Ph.D. Candidate, Computer Science Virginia Tech _______________________________________________ dtrace-discuss mailing list [email protected]
