Messages in this thread | | | Date | Thu, 26 Jul 2012 17:02:22 +0400 | From | Alexey Vlasov <> | Subject | Re: Attaching a process to cgroups |
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On Wed, Jul 25, 2012 at 03:57:47PM +0200, Mike Galbraith wrote: > > I'd profile it with perf, and expect to find a large pile of cycles.
I did it the as following: # perf stat cat /proc/self/cgroup
4:blkio:/ 3:devices:/ 2:memory:/ 1:cpuacct:/
Performance counter stats for 'cat /proc/self/cgroup':
0.472513 task-clock # 0.000 CPUs utilized 1 context-switches # 0.002 M/sec 1 CPU-migrations # 0.002 M/sec 169 page-faults # 0.358 M/sec 1111521 cycles # 2.352 GHz 784737 stalled-cycles-frontend # 70.60% frontend cycles idle 445520 stalled-cycles-backend # 40.08% backend cycles idle 576622 instructions # 0.52 insns per cycle # 1.36 stalled cycles per insn 120032 branches # 254.029 M/sec 6577 branch-misses # 5.48% of all branches
9.114631804 seconds time elapsed
# perf report --sort comm,dso Kernel address maps (/proc/{kallsyms,modules}) were restricted.
Check /proc/sys/kernel/kptr_restrict before running 'perf record'.
If some relocation was applied (e.g. kexec) symbols may be misresolved.
Samples in kernel modules can't be resolved as well.
# ======== # captured on: Thu Jul 26 16:23:06 2012 # hostname : l24 # os release : 3.3.3-1gb-c-s-m # perf version : 3.2 # arch : x86_64 # nrcpus online : 24 # nrcpus avail : 24 # cpudesc : Intel(R) Xeon(R) CPU E5645 @ 2.40GHz # total memory : 74181032 kB # cmdline : /usr/sbin/perf record cat /proc/self/cgroup # event : name = cycles, type = 0, config = 0x0, config1 = 0x0, config2 = 0x0, excl_usr = 0, excl_kern = 0, id = { 1758, 1759, 1760, 1761, 1762, 1763, 1764, 1765, 1766, 1767, 1768, 1769, 1770, 1771, 1772, 1773, 1774, 1775, 1776, 1777, 1778, 1779, 1780, 1781 } # HEADER_CPU_TOPOLOGY info available, use -I to display # HEADER_NUMA_TOPOLOGY info available, use -I to display # ======== # # Events: 21 cycles # # Overhead Command Shared Object # ........ ....... ................. # 100.00% cat [kernel.kallsyms]
but I don't know what next unfortunately.
I also checked the same thing on the other server with the 2.6.37 kernel, there' some thousands cgroups too, and it somehow works there immediately.
-- Alexey Vlasov
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