On Thu, 21 May 2009 14:47:17 +0800
anqin <anqin.qin@xxxxxxxxx> wrote:
> > I wonder....
> >
> > max_usage_in_bytes is not _reseted_ when you specified limit.
> > Then, please set limit before attaching task.
> >
> > Sane sequence is.
> > 1. mount
> > 2. mkdir
> > 3. set limit
> > 4. attach.
> >
> >
>
> I have tried again the experiment based on the above rules,
> but I get the same result.
>
> Again, my operations are as follows: (I have prepared three shell, #1,
> #2 and #3)
>
> a) In shell #1, prepare a bash :
>
> # bash
> # echo $$
> 11026
>
> b) In shell #2, prepare the memory control via cgroupfs:
>
> # mount -t cgroup cgroup /mnt/mycgrp2
> # cd /mn/mycgrp2
> # mkdir mycontainer2
> # cd mycontainer2
> # echo 0 > cpuset.mems
> # echo 0-1 > cpuset.cpus
> # echo 350000 > memory.limit_in_bytes
>
> # cat memory.usage_in_bytes
> 0
> # cat memory.max_usage_in_bytes
> 0
> # cat memory.limit_in_bytes
> 352256
>
> # echo 11026 > tasks
> # cat tasks
> 11026
>
>
> c) In Shell #1, run a memory consumer (in which, malloc() is called
> to allocate memory and not free until program is existed) to allocate
> 500M memory:
>
>
> # ./memconsume 500
> Begin allocate block ... OK
> allocate No.2 block ... OK
> ...
>
> d) In Shell #3, run the top and see the memory consumption of memconsume:
>
> # ps -ef | grep memconsume
> root 11667 11647 0 00:40 pts/0 00:00:00 ./memconsume 500
> root 11671 10536 0 00:56 pts/2 00:00:00 grep memconsume
> # top -p 11667
>
> e) In Sehll #2, I cat the usage_in_bytes to see the ascending
> change of memory:
>
> # cat memory.usage_in_bytes
> 143360
> # cat memory.usage_in_bytes
> 159744
> # cat memory.usage_in_bytes
> 233472
> ...
> # cat memory.usage_in_bytes //<-- hit the max limited value
> 352256
> # cat memory.usage_in_bytes
> 258048
> # cat memory.usage_in_bytes
> 282624
> ...
> # cat memory.usage_in_bytes // <-- hit the max limited value
> 348160
> # cat memory.usage_in_bytes
> 122880
> ...
>
Ok, them, usage_in_bytes doesn't exceed limit. As expected.
> On the other hand, the top shown in Shell #3 that the virtual
> memory is growing up to 450M, but RES is fluctuating between
> 615 and 497 and the %MEM always shows 0.2 and 0.3 in the whole
> experiment.
>
Ok.
> Does the phenomena conform with the behaviors of memroy cgroups?
> Currently, the memory cgroups can not kill the processes or limit
> their further allocation of memory when the processes call for more
> memory, right?
>
right. memcg doesn't prevent malloc or mmap. but controls usage of "physical"
memory.
> Maybe, something wrong in my test codes. The following is the
> code of memconsume.c
>
> ------------------------ memconsume.c ----------------------------
>
> #include <stdio.h>
> #include <stdlib.h>
> #include <unistd.h>
>
> int main(int argc, char *argv[])
> {
> int i, t_total;
> char *p = NULL;
>
> if (argc != 2) {
> printf("Usage: %s number (block = 1M) \n", argv[0]);
> return -1;
> }
>
> i = t_total = 0;
>
> t_total = atoi(argv[1]);
> if (t_total == 0) {
> printf("Usage: %s number (kb) \n", argv[0]);
> printf("\t- number is integer (kb)\n");
> return -1;
> }
>
> printf("Begin allocate memory ...");
>
> while (1) {
> p = NULL;
> p = (char *) malloc(1024 * 1024);
> if (p) {
> printf("OK\n");
> i++;
> if (i >= t_total)
> break;
> } else
> printf("fail\n");
> sleep(1);
> printf("allocate No.%d block ...", i + 1);
> }
You need to call memset() or some to use "physical" memory by page fault.
malloc just allocates virtual address. (and this program will start to use
swap.)
BTW, Try
# echo 300M > .../memory.memsw.limit_in_bytes
If you config CGROUP_MEM_RES_CTRL_SWAP. You can limit mem+swap usage.
Thanks,
-Kame
>
>
> printf("End the consumption, total memory = %d * 1024 * 1024 bytes\n", i);
> return 0;
> }
>
>
> ------------------------------------------------------------------------------
>
> Thanks again,
>
> Anqin
>
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