Re: [dev] [wmii] likely memory leak

On Wed, Feb 23, 2011 at 02:40:18PM -0500, Kris Maglione wrote:
> On Fri, Feb 18, 2011 at 09:15:14PM +0300, Roman Belov wrote:
> >I use wmii-3.9.2-r1 (gentoo ebuild) on my workstation. Today I looked at
> >memory usage and saw that wmii had been occupying all memory and swap.
> >Uptime was about three month.
> >
> >I am trying to reproduce this issue at home with wmii-9999 (hg, cloned today).
> >Seems the devel version has this issue too.
>
> Ok, I looked into this and it turns out that it wasn't a leak.
> Certain structures used in the filesystem are allocated from a
> free list because they're used in huge numbers. However, in one
> particular place, a structure was allocated directly rather than
> taken from the free list, and was re-added to the free list
> later, and thus the free list grew without bound by one
> structure for each filesystem walk. It should be fixed by
> revision 141:339db5c6d2c9 in the libixp repo.
>

It did not fix the problem, that free list is actually bounded now (I
checked) but memory usage still grows.

I have performed a little investigation. Valgrind shows that it is not a
leak again. So I captured and analysed call logs of malloc/free/etc.
functions. I found that some block of 48 bytes is periodically (likely
it is status line update activity) allocated but is never freed. From
gdb stack backtraces I see only one place where such block is allocated.

#0 0xb749b0b6 in malloc () from /lib/libc.so.6
No symbol table info available.
#1 0x0806a22b in ixp_emalloc (size=48) at util.c:198
        ret = 0x1
#2 0x0806a25d in ixp_emallocz (size=48) at util.c:207
        ret = 0xbff42688
#3 0x08066bc3 in createfid (map=0x80d632c, fid=2, p9conn=0x80d6320) at request.c:91
        f = 0x80e14f8
#4 0x080674a4 in handlereq (r=0x80e1240) at request.c:296
        p9conn = 0x80d6320
        srv = 0x80806e0
#5 0x08066df4 in handlefcall (c=0x80d5278) at request.c:146
        (Dropped a lot of data)
        p9conn = 0x80d6320
        req = 0x80e1240
#6 0x080681e3 in handle_conns (s=0x80866c0) at server.c:118
        c = 0x80d5278
        n = 0x80c5d88
#7 0x08068316 in ixp_serverloop (srv=0x80866c0) at server.c:169
        tvp = 0xbff428dc
        tv = {tv_sec = 0, tv_usec = 381988}
        timeout = 382
        r = 1
#8 0x0805c903 in main (argc=0, argv=0xbff42a78) at main.c:436
        oargv = 0xbff42a74
        wmiirc = 0x807c3bc "wmiirc"
        i = -1074517560
        _argtmp = 0
        _inargv = 0
        _argv = 0x0

Unfortunately, I am not familiar with libixp code to decide what is
wrong.
Received on Mon Feb 28 2011 - 22:12:11 CET