Hi, Mike.
if the package AddressSanitizer (ASan) is available, you might want to
ive it a go. It is a fast memory error detector. that can find
use-after-free and {heap,stack,global}-buffer overflow bugs in C/C++
programs. it's here:
https://code.google.com/p/address-sanitizer/
Good luck....I still think C/C++ will be the death of us all. :-)
DJ
On 07/09/2015 07:50 AM, Pavelka, Tomas wrote:
> Look at the " -/+ buffers/cache" line in the free output:
>
> Before:
> -/+ buffers/cache: 41 450
> After:
> -/+ buffers/cache: 48 443
>
> (First number used, second free)
>
> Linux has various buffers and caches that are allocated if there is free
> memory. For example for disk reads. These are dropped if the memory is needed
> by processes. The " -/+ buffers/cache" line shows what memory is actually
> used by processes and not the buffers. In your case the used memory rose only
> by 7 MB.
>
> BTW I would not look at the virtual memory size of proceses, this may be
> allocated way over the virtual memory size of your machine. The more
> interesting metric is RSS which is how much memory is actually used.
>
> HTH,
> Tomas
>
> Tomas Pavelka
> CA Technologies
> Sr Software Engineer
>
> CA CZ, s.r.o
> V Parku 12,
> 148 00 Praha
> Czech Republic
>
> Office: +25996 | [email protected]
>
>
>
> Id. Císlo 25694073, z obchodního rejstříku, vedeného Městským soudem v Praze,
> oddíl C, vložka 61808 / Id. No. 25694073, registered in the Commercial
> Register maintained by the Municipal Court in Praque, Section C, File 61808
>
>
> -----Original Message-----
> From: Linux on 390 Port [mailto:[email protected]] On Behalf Of Michael
> MacIsaac
> Sent: Thursday, July 09, 2015 2:19 PM
> To: [email protected]
> Subject: How to find a memory leak?
>
> Hello list,
>
> I have a SLES 11 SP3 system that is leaking memory, but I don't know how or
> where.
>
> I find a script on the Internet that runs forever, adapt it somewhat, and
> start logging some info to a temp file. Here's the script:
>
> # cat memusage
> #!/bin/bash
> #
> # track memory usage
> #
> outFile="/tmp/memusage"
> while true
> do
> echo "---------------------------------------------------" >> $outFile
> date >> $outFile
> ps aux --sort -vsz | head -22 >> $outFile
> echo >> $outFile
> free -m >> $outFile
> sleep 300
> done
>
> After a fresh reboot of a 512 MB virtual machine, I start the script and the
> first entry in the temp file shows about 20 MB (512 - 492) used by Linux and
> 97 MB used by processes:
>
> Wed Jul 8 12:37:45 EDT 2015
> USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
> root 2181 0.0 0.2 115404 1024 ? Ssl 12:36 0:00
> /usr/sbin/nscd
> root 1851 0.0 0.1 11512 692 ? S<sl 12:36 0:00
> /sbin/auditd -s disable
> root 2556 0.3 0.7 11456 4004 ? Ss 12:37 0:00 sshd:
> root@pts/0
> root 2306 0.0 0.7 10720 3700 ? Ss 12:36 0:00
> /usr/sbin/httpd2-prefork
> wwwrun 2307 0.0 0.4 10720 2204 ? S 12:36 0:00
> /usr/sbin/httpd2-prefork
> wwwrun 2308 0.0 0.4 10720 2204 ? S 12:36 0:00
> /usr/sbin/httpd2-prefork
> wwwrun 2309 0.0 0.4 10720 2204 ? S 12:36 0:00
> /usr/sbin/httpd2-prefork
> wwwrun 2310 0.0 0.4 10720 2204 ? S 12:36 0:00
> /usr/sbin/httpd2-prefork
> wwwrun 2311 0.0 0.4 10720 2204 ? S 12:36 0:00
> /usr/sbin/httpd2-prefork
> root 1853 0.0 0.1 10428 824 ? S<sl 12:36 0:00
> /sbin/audispd
> root 997 0.0 0.6 9036 3224 ? Ssl 12:36 0:00
> /usr/sbin/console-kit-da
> root 2265 0.0 0.5 8136 2532 ? Ss 12:36 0:00
> /usr/lib/postfix/master
> postfix 2277 0.0 0.4 8004 2372 ? S 12:36 0:00 qmgr -l -t
> fifo -u
> postfix 2276 0.0 0.4 7948 2352 ? S 12:36 0:00 pickup -l
> -t fifo -u
> root 2172 0.0 0.3 7916 1532 ? Ss 12:36 0:00
> /usr/sbin/sshd -o PidFi
> 101 994 0.0 0.5 7852 2804 ? Ss 12:36 0:00
> /usr/sbin/hald --daemon
> root 1869 0.0 0.8 6464 4504 ? Ss 12:36 0:00
> /sbin/haveged -w 1024 -
> root 2559 1.0 0.6 6056 3076 pts/0 Ss 12:37 0:00 -bash
> root 998 0.0 0.2 3980 1332 ? S 12:36 0:00 hald-runner
> root 2591 0.0 0.3 3652 1604 pts/0 S+ 12:37 0:00 /bin/bash
> /usr/local/sb
> root 2343 0.0 0.1 3508 944 ? Ss 12:36 0:00
> /usr/sbin/xinetd -pidfi
>
> total used free shared buffers cached
> Mem: *492 97* 394 0 5 50
> -/+ buffers/cache: 41 450
> Swap: 898 0 898
>
> This morning the last entry shows 156 MB used by processes: ~59 MB of memory
> lost in less than a day. But the 'VSZ' of the top 22 processes seems to be
> about the same:
>
> Thu Jul 9 07:57:47 EDT 2015
> USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND
> root 2181 0.0 0.2 115404 1088 ? Ssl Jul08 0:00
> /usr/sbin/nscd
> root 1851 0.0 0.1 11512 692 ? S<sl Jul08 0:00
> /sbin/auditd -s disable
> root 44879 0.0 0.7 11456 4008 ? Ss 07:36 0:00 sshd:
> root@pts/1
> root 44913 0.0 0.7 11456 4008 ? Ss 07:37 0:00 sshd:
> root@pts/2
> root 2306 0.0 0.7 10720 3700 ? Ss Jul08 0:01
> /usr/sbin/httpd2-prefork
> wwwrun 2307 0.0 0.4 10720 2204 ? S Jul08 0:00
> /usr/sbin/httpd2-prefork
> wwwrun 2308 0.0 0.4 10720 2204 ? S Jul08 0:00
> /usr/sbin/httpd2-prefork
> wwwrun 2309 0.0 0.4 10720 2204 ? S Jul08 0:00
> /usr/sbin/httpd2-prefork
> wwwrun 2310 0.0 0.4 10720 2204 ? S Jul08 0:00
> /usr/sbin/httpd2-prefork
> wwwrun 2311 0.0 0.4 10720 2204 ? S Jul08 0:00
> /usr/sbin/httpd2-prefork
> root 1853 0.0 0.1 10428 824 ? S<sl Jul08 0:00
> /sbin/audispd
> root 997 0.0 0.6 9036 3224 ? Ssl Jul08 0:00
> /usr/sbin/console-kit-da
> root 2265 0.0 0.5 8136 2532 ? Ss Jul08 0:00
> /usr/lib/postfix/master
> postfix 2277 0.0 0.4 8004 2372 ? S Jul08 0:00 qmgr -l -t
> fifo -u
> postfix 44778 0.0 0.4 7948 2356 ? S 06:56 0:00 pickup -l
> -t fifo -u
> root 2172 0.0 0.3 7916 1664 ? Ss Jul08 0:00
> /usr/sbin/sshd -o PidFi
> 101 994 0.0 0.5 7852 2852 ? Ss Jul08 0:00
> /usr/sbin/hald --daemon
> root 1869 0.0 0.8 6464 4504 ? Ss Jul08 0:00
> /sbin/haveged -w 1024 -
> root 44882 0.0 0.6 6056 3052 pts/1 Ss 07:36 0:00 -bash
> root 44916 0.0 0.5 6056 2876 pts/2 Ss+ 07:37 0:00 -bash
> mike 44992 0.0 0.5 6056 3004 pts/1 S+ 07:56 0:00 -bash
>
> total used free shared buffers cached
> Mem: *492 156 * 335 0 24 83
> -/+ buffers/cache: 48 443
> Swap: 898 0 898
>
> Is there a better way to detect memory leaks? Are there any known
> 'culprits'?
>
> Any help will be appreciated. Thanks.
>
> -Mike MacIsaac
>
> ----------------------------------------------------------------------
> For LINUX-390 subscribe / signoff / archive access instructions, send email
> to [email protected] with the message: INFO LINUX-390 or visit
> http://www.marist.edu/htbin/wlvindex?LINUX-390
> ----------------------------------------------------------------------
> For more information on Linux on System z, visit http://wiki.linuxvm.org/
>
--
Dave Jones
Houston, TX
281.578.7544
----------------------------------------------------------------------
For LINUX-390 subscribe / signoff / archive access instructions,
send email to [email protected] with the message: INFO LINUX-390 or visit
http://www.marist.edu/htbin/wlvindex?LINUX-390
----------------------------------------------------------------------
For more information on Linux on System z, visit
http://wiki.linuxvm.org/
