Attaching a process to cgroups

[Alexey Vlasov <renton@renton.name>]

Hi.

Is it possible to somehow fasten a process of pid attaching to cgroup?
The problem is the pid attaches to a task-file with some strange delay:

22:28:00.788224 open("/sys/fs/cgroup/memory/virtwww/w_test-l24-apache1_4bdf3d13/apache/tasks", O_WRONLY|O_CREAT|O_APPEND, 0666) = 3 <0.000035>
22:28:00.788289 fstat(3, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0 <0.000004>
22:28:00.788326 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f5e78074000 <0.000005>
22:28:00.788355 fstat(3, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0 <0.000004>
22:28:00.788389 lseek(3, 0, SEEK_SET)   = 0 <0.000004>
22:28:00.788426 write(3, "16317\n", 6)  = 6 <0.128094>
22:28:00.916578 close(3)                = 0 <0.000006>

For a comparison here's a test attaching pid-file in placed tmpfs: 

22:24:41.892562 open("/tmp/w_test-l24-apache1_4bdf3d13/tasks", O_WRONLY|O_CREAT|O_APPEND, 0666) = 3 <0.000010>
22:24:41.892597 fstat(3, {st_mode=S_IFREG|0644, st_size=6, ...}) = 0 <0.000004>
22:24:41.892631 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f5685b6f000 <0.000006>
22:24:41.892664 fstat(3, {st_mode=S_IFREG|0644, st_size=6, ...}) = 0 <0.000004>
22:24:41.892701 lseek(3, 6, SEEK_SET)   = 6 <0.000004>
22:24:41.892738 write(3, "25966\n", 6)  = 6 <0.000008>
22:24:41.892767 close(3)                = 0 <0.000005>

Here goes it immediately.

-- 
BRGDS. Alexey Vlasov.