On 08/25/2012 01:45 PM, Richard Davies wrote:
Are you talking about these patches? http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=commit;h=c67fe3752abe6ab47639e2f9b836900c3dc3da84 http://marc.info/?l=linux-mm&m=134521289221259 If so, I believe those are in 3.6.0-rc3, so I tested with that. Unfortunately, I can still get the slow boots and perf top showing _raw_spin_lock_irqsave. Here are two perf top traces on 3.6.0-rc3. They do look a bit different from 3.5.2, but _raw_spin_lock_irqsave is still at the top: PerfTop: 35272 irqs/sec kernel:98.1% exact: 0.0% [4000Hz cycles], (all, 16 CPUs) ------------------------------------------------------------------------------------------------------------------ 61.85% [kernel] [k] _raw_spin_lock_irqsave 7.18% [kernel] [k] sub_preempt_count 5.03% [kernel] [k] isolate_freepages_block 2.49% [kernel] [k] yield_to 2.05% [kernel] [k] memcmp 2.01% [kernel] [k] compact_zone 1.76% [kernel] [k] add_preempt_count 1.52% [kernel] [k] _raw_spin_lock 1.31% [kernel] [k] kvm_vcpu_on_spin 0.92% [kernel] [k] svm_vcpu_run
However, the compaction code is not as prominent as before. Can you get a backtrace to that _raw_spin_lock_irqsave, to see from where it is running into lock contention? It would be good to know whether it is isolate_freepages_block, yield_to, kvm_vcpu_on_spin or something else... -- All rights reversed -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
