Re: [squid-users] Memory leak Squid Cache: Version 3.1.16 + FreeBSD 7.4-STABLE

 On Tue, 1 Nov 2011 16:42:13 +0700, budsz wrote:
> Hallo,
>
> After port cvsup, updating lib, packages and so on. I got something
> weird problem, I guess this cause memory leak.
>
> root:~# free
> SYSTEM MEMORY SUMMARY:
> mem_used: 574558208 ( 547MB) [ 53%] Logically used memory
> mem_avail: + 499183616 ( 476MB) [ 46%] Logically available
> memory
> -------------- ------------ ----------- ------
> mem_total: = 1073741824 ( 1024MB) [100%] Logically total memory
>
> root:~# /usr/local/etc/rc.d/squid stop
>
> "mem_used:" back to 23%.
>

 Note that Squid uses memory for a lot of things, most of them in very
 large blocks or large number of small blocks. The OS does not account
 for memory released.

> root:~# valgrind -v --tool=memcheck --leak-check=yes squid
>
> *snip*
> ==45738== 1 errors in context 2 of 39:
> ==45738== Mismatched free() / delete / delete []
> ==45738== at 0x4B9D5: operator delete(void*) (in
> /usr/local/lib/valgrind/vgpreload_memcheck-x86-freebsd.so)
> ==45738== by 0xE0518: std::basic_ostringstream<char,
> std::char_traits<char>, std::allocator<char>
> >::~basic_ostringstream()
> (in /usr/lib/libstdc++.so.6)
> ==45738== by 0x8091369: Debug::finishDebug() (debug.cc:753)
> ==45738== by 0x81036FD: PconnModule::PconnModule() (pconn.cc:348)
> ==45738== by 0x8103739: PconnModule::GetInstance() (pconn.cc:356)
> ==45738== by 0x8103CDE: PconnPool::PconnPool(char const*)
> (pconn.cc:241)
> ==45738== by 0x80A5C0F:
> __static_initialization_and_destruction_0(int, int) (forward.cc:76)
> ==45738== by 0x80A5C59: global constructors keyed to
> _ZN8FwdState15CBDATA_FwdStateE (forward.cc:1464)
> ==45738== by 0x81ABDD7: ??? (in /usr/local/sbin/squid)
> ==45738== by 0x804BAD4: ??? (in /usr/local/sbin/squid)
> ==45738== by 0x804CBB7: (below main) (in /usr/local/sbin/squid)
> ==45738== Address 0x2e8180 is 0 bytes inside a block of size 180
> alloc'd
> ==45738== at 0x4C0F5: malloc (in
> /usr/local/lib/valgrind/vgpreload_memcheck-x86-freebsd.so)
> ==45738== by 0x81AB1DD: xmalloc (util.c:508)
> ==45738== by 0x8050DA0: operator new(unsigned int) (SquidNew.h:49)
> ==45738== by 0x8090C14: Debug::getDebugOut() (debug.cc:735)
> ==45738== by 0x81036E8: PconnModule::PconnModule() (pconn.cc:348)
> ==45738== by 0x8103739: PconnModule::GetInstance() (pconn.cc:356)
> ==45738== by 0x8103CDE: PconnPool::PconnPool(char const*)
> (pconn.cc:241)
> ==45738== by 0x80A5C0F:
> __static_initialization_and_destruction_0(int, int) (forward.cc:76)
> ==45738== by 0x80A5C59: global constructors keyed to
> _ZN8FwdState15CBDATA_FwdStateE (forward.cc:1464)
> ==45738== by 0x81ABDD7: ??? (in /usr/local/sbin/squid)
> ==45738== by 0x804BAD4: ??? (in /usr/local/sbin/squid)
> ==45738== by 0x804CBB7: (below main) (in /usr/local/sbin/squid)
> ==45738==
> ==45738== ERROR SUMMARY: 39 errors from 39 contexts (suppressed: 0
> from 0)
> *snip*
>
> Anyone have a clue?

 For some reason your compiler is using Squids internal overloaded
 definition of new() and failing to use the matching definition for
 delete() which is defined in an identical way right next to it. This
 could be a problems since they go through two different memory
 accounting systems and this will leave Squid allocated RAM counters
 forever going upward.

 You snipped away the details about RAM impact. Reconstructing from the
 trace count and size this appears to only be leaking a total of 7KB.
 Somehow it seems there is something else going on.
 Amos
Received on Tue Nov 01 2011 - 23:01:35 MDT