On 1/28/19 9:57 AM, Sergey Senozhatsky wrote: > Hello, > > next-20190125 > > kcompactd0 is spinning on something, burning CPUs in the meantime: Hi, could you check/add this to the earlier thread? Thanks. https://lore.kernel.org/lkml/20190126200005.GB27513@amd/T/#u > > %CPU TIME+ COMMAND > 100.0 0.0 34:04.20 R [kcompactd0] > > Not sure I know how to reproduce it; so am probably not going to > be a very helpful tester. > > I tried to ftrace kcompactd0 PID, and I see the same path all over > the tracing file: > > 2) 0.119 us | unlock_page(); > 2) 0.109 us | unlock_page(); > 2) 0.096 us | compaction_free(); > 2) 0.104 us | ___might_sleep(); > 2) 0.121 us | compaction_alloc(); > 2) 0.111 us | page_mapped(); > 2) 0.105 us | page_mapped(); > 2) | move_to_new_page() { > 2) 0.102 us | page_mapping(); > 2) | buffer_migrate_page_norefs() { > 2) | __buffer_migrate_page() { > 2) | expected_page_refs() { > 2) 0.118 us | page_mapping(); > 2) 0.321 us | } > 2) | __might_sleep() { > 2) 0.122 us | ___might_sleep(); > 2) 0.332 us | } > 2) | _raw_spin_lock() { > 2) 0.115 us | preempt_count_add(); > 2) 0.321 us | } > 2) | _raw_spin_unlock() { > 2) 0.114 us | preempt_count_sub(); > 2) 0.321 us | } > 2) | invalidate_bh_lrus() { > 2) | on_each_cpu_cond() { > 2) | on_each_cpu_cond_mask() { > 2) | __might_sleep() { > 2) 0.114 us | ___might_sleep(); > 2) 0.316 us | } > 2) 0.109 us | preempt_count_add(); > 2) 0.128 us | has_bh_in_lru(); > 2) 0.105 us | has_bh_in_lru(); > 2) 0.124 us | has_bh_in_lru(); > 2) 0.103 us | has_bh_in_lru(); > 2) 0.125 us | has_bh_in_lru(); > 2) 0.105 us | has_bh_in_lru(); > 2) 0.123 us | has_bh_in_lru(); > 2) 0.107 us | has_bh_in_lru(); > 2) | on_each_cpu_mask() { > 2) 0.104 us | preempt_count_add(); > 2) 0.110 us | smp_call_function_many(); > 2) 0.105 us | preempt_count_sub(); > 2) 0.764 us | } > 2) 0.116 us | preempt_count_sub(); > 2) 3.676 us | } > 2) 3.889 us | } > 2) 4.087 us | } > 2) | _raw_spin_lock() { > 2) 0.112 us | preempt_count_add(); > 2) 0.315 us | } > 2) | _raw_spin_unlock() { > 2) 0.108 us | preempt_count_sub(); > 2) 0.309 us | } > 2) | unlock_buffer() { > 2) | wake_up_bit() { > 2) 0.118 us | __wake_up_bit(); > 2) 0.317 us | } > 2) 0.513 us | } > 2) 7.440 us | } > 2) 7.643 us | } > 2) 8.070 us | } > > > PG migration fails a lot: > > pgmigrate_success 111063 > pgmigrate_fail 269841559 > compact_migrate_scanned 536253365 > compact_free_scanned 360889 > compact_isolated 270072733 > compact_stall 0 > compact_fail 0 > compact_success 0 > compact_daemon_wake 56 > compact_daemon_migrate_scanned 536253365 > compact_daemon_free_scanned 360889 > > Let me know if I can help with anything else. I'll keep the the box alive > for a while, but will have to power it off eventually. > > -ss >
