I found a solution without hacking into the library itself. Since my system is running glibc, I forced all mem request to use mmap with mallopt(M_MMAP_THRESHOLD, 0), which release the memory back to the system when free is called, testing shows so far so good.
-- qun-ying ----- Original Message ---- > From: David Schwartz <dav...@webmaster.com> > To: openssl-users@openssl.org > Cc: Scott Neugroschl <scot...@xypro.com> > Sent: Tue, September 28, 2010 3:08:48 PM > Subject: Re: where is the memory being held > > On 9/27/2010 4:13 PM, Scott Neugroschl wrote: > > As David said, yes. > > On the other hand, you could re-implement malloc() and free() for your > > platform. > > There's really no way to make that help very much. It might help a little, > but >the fundamental problem is this: > > If you want to implement each 'malloc' so that a later 'free' can return the >memory to the operating system, you can. But that requires rounding up even >small allocations to at least a page, which increases your memory footprint. > > If you don't implement each 'malloc' that way, you still wind up with the >problem that one small allocation that has not been freed in the middle of a >bunch of larger allocations that have been freed prevents you from returning >any of the memory used by the larger allocations to the operating system. > > Generally, what you need are algorithms designed for low memory footprint > and >a way to 'group' allocations that will tend to be freed as a unit (such as >those related to a single SSL session) such that when they are all freed, the >memory can be returned to the OS. OpenSSL simply is not designed this way. > > You could probably hack OpenSSL to pass a pointer to a session object to > calls >to malloc/free (perhaps using TSD) and use that TSD pointer as an allocation >context. That might increase the chances that the whole allocation context is >freed. It may even be sufficient (or at least helpful) just to hook all >OpenSSL >calls to malloc/free and process them from their own arena. > > DS > > ______________________________________________________________________ > OpenSSL Project http://www.openssl.org > User Support Mailing List openssl-users@openssl.org > Automated List Manager majord...@openssl.org > ______________________________________________________________________ OpenSSL Project http://www.openssl.org User Support Mailing List openssl-users@openssl.org Automated List Manager majord...@openssl.org
