| Summary: | Bad scalability with memory cgroups. | ||
|---|---|---|---|
| Product: | Red Hat Enterprise Linux 6 | Reporter: | Xavier Bru <xavier.bru> |
| Component: | kernel | Assignee: | Red Hat Kernel Manager <kernel-mgr> |
| Status: | CLOSED DUPLICATE | QA Contact: | Red Hat Kernel QE team <kernel-qe> |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | 6.1 | CC: | gasmith |
| Target Milestone: | rc | ||
| Target Release: | --- | ||
| Hardware: | Unspecified | ||
| OS: | Unspecified | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | Bug Fix | |
| Doc Text: | Story Points: | --- | |
| Clone Of: | Environment: | ||
| Last Closed: | 2011-09-09 11:35:35 UTC | Type: | --- |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
@xavier Is this the same issue as reported from Bull via myself at: https://bugzilla.redhat.com/show_bug.cgi?id=717803 ? Yes,....Sorry I missed it was already opened as a Bugzilla. No problem. I'll closed this BZ as a DUPLICATE of the other. Can I ask you to please add the above information (and any additional data) as a new comment on the other BZ? (so that it is seen to come from an @bull.net address rather than an internal @redhat.com address). *** This bug has been marked as a duplicate of bug 717803 *** |
Description of problem: Bad scalability with memory cgroups. Version-Release number of selected component (if applicable): 2.6.32-131.12.1 How reproducible: run a program that allocates memory on a 32 cpu system Steps to Reproduce: 1. create a user Memory Cgroup 2. run 32 occurences of program that allocates memory 3. compare time with same program executed outside Memory cgroup or with cgroup_disable=memory Actual results: . in cgroup memory: Time for Allocating Buffers : 100.222279 second(s) 75.70% _spin_lock res_counter_uncharge Expected results: . outside cgroup memory: Time for Allocating Buffers : 3.721997 second(s) Additional info: perf profiling shows contention on cgroup spinlock. This has been reworked in recent kernels to coalesce the accounting on cgroup. 2.6.37 kernel does not show the problem of scalability. 75.70% malloc_seq [kernel.kallsyms] [k] _s | --- _spin_lock | |--52.11%-- res_counter_uncharge | __mem_cgroup_uncharge_common | mem_cgroup_uncharge_page | page_remove_rmap | unmap_vmas | exit_mmap | mmput | | | |--100.00%-- exit_mm | | do_exit | | do_group_exit | | sys_exit_group | | system_call_fastpath | --0.00%-- [...] | |--47.86%-- res_counter_charge