Le 18.08.2012 11:56, Alex Bligh a écrit :
> --On 18 August 2012
11:35:29 +0200 Denis BUCHER
> wrote:
>
>> OK, but my problem is that
when I detect an "offending" process (using too much memory), it's
already too late ! The strace will only show mmaps until "[crit] Memory
allocation failed" ! Do you have a suggestion on how I could "intercept"
these processes before the problem happens ?
>
> rlimit maybe.
>
> I'd
suggest something is trying to allocate a 'negative' amount of memory.
>
The real answer is to locate the bug. If you really want to do that,
>
build/install debug versions of your s/w, attach gdb to the running
>
process, and ask for a backtrace.
Mmmm I don't know how to to all
that...
I just send you the end of strace, just by chance, maybe you
can see something interesting ?
> mmap(NULL, 1048576,
PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0x2b92e9929000
> brk(0x2b91bbe72000) = 0x2b91bbe16000
> mmap(NULL,
1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0x2b92e9a29000
> brk(0x2b91bbe72000) = 0x2b91bbe16000
> mmap(NULL,
1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0x2b92e9b29000
> brk(0x2b91bbe72000) = 0x2b91bbe16000
> mmap(NULL,
1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0x2b92e9c29000
> brk(0x2b91bbe72000) = 0x2b91bbe16000
> mmap(NULL,
1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =
0x2b92e9d29000
> brk(0x2b91bbe72000) = 0x2b91bbe16000
> mmap(NULL,
1048576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = -1
ENOMEM (Cannot allocate memory)
> mmap(NULL, 134217728, PROT_NONE,
MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0) = 0x2b92e9f29000
>
munmap(0x2b92e9f29000, 34435072) = 0
> munmap(0x2b92f0000000, 32673792)
= 0
> mprotect(0x2b92ec000000, 376832, PROT_READ|PROT_WRITE) = -1 ENOMEM
(Cannot allocate memory)
> munmap(0x2b92ec000000, 67108864) = 0
>
mmap(NULL, 134217728, PROT_NONE,
MAP_PRIVATE|MAP_ANONYMOUS|MAP_NORESERVE, -1, 0) = 0x2b92e9e29000
>
munmap(0x2b92e9e29000, 35483648) = 0
> munmap(0x2b92f0000000, 31625216)
= 0
> mprotect(0x2b92ec000000, 135168, PROT_READ|PROT_WRITE) = -1 ENOMEM
(Cannot allocate memory)
> munmap(0x2b92ec000000, 67108864) = 0
>
write(2, "[crit] Memory allocation failed,"..., 51) = 51
>
rt_sigprocmask(SIG_UNBLOCK, [ABRT], NULL, 8) = 0
> tgkill(17282, 17282,
SIGABRT) = 0
> --- SIGABRT (Aborted) @ 0 (0) ---
> chdir("/etc/httpd") =
0
> rt_sigaction(SIGABRT, {SIG_DFL, [], SA_RESTORER|SA_INTERRUPT,
0x2b91b7f33be0}, {SIG_DFL, [], SA_RESTORER|SA_RESETHAND,
0x2b91b7f33be0}, 8) = 0
> kill(17282, SIGABRT) = 0
>
rt_sigreturn(0x4382) = 0
> --- SIGABRT (Aborted) @ 0 (0) ---
> Process
17282 detached
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