Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1574547

Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages per zone

From Michal Hocko <mhocko@kernel.org>
Newsgroups linux.kernel
Subject Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages per zone
Date 2017-02-06 11:40 +0100
Message-ID <t7OSe-3KY-33@gated-at.bofh.it> (permalink)
References (1 earlier) <t5fYC-1PU-9@gated-at.bofh.it> <t6mEG-2zZ-19@gated-at.bofh.it> <t6JUC-QC-19@gated-at.bofh.it> <t6Nvb-2PE-3@gated-at.bofh.it> <t7syl-6ab-11@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


On Sun 05-02-17 19:43:07, Tetsuo Handa wrote:
> Michal Hocko wrote:
> I got same warning with ext4. Maybe we need to check carefully.
> 
> [  511.215743] =====================================================
> [  511.218003] WARNING: RECLAIM_FS-safe -> RECLAIM_FS-unsafe lock order detected
> [  511.220031] 4.10.0-rc6-next-20170202+ #500 Not tainted
> [  511.221689] -----------------------------------------------------
> [  511.223579] a.out/49302 [HC0[0]:SC0[0]:HE1:SE1] is trying to acquire:
> [  511.225533]  (cpu_hotplug.dep_map){++++++}, at: [<ffffffff810a1477>] get_online_cpus+0x37/0x80
> [  511.227795] 
> [  511.227795] and this task is already holding:
> [  511.230082]  (jbd2_handle){++++-.}, at: [<ffffffff813a8be7>] start_this_handle+0x1a7/0x590
> [  511.232592] which would create a new lock dependency:
> [  511.234192]  (jbd2_handle){++++-.} -> (cpu_hotplug.dep_map){++++++}
> [  511.235966] 
> [  511.235966] but this new dependency connects a RECLAIM_FS-irq-safe lock:
> [  511.238563]  (jbd2_handle){++++-.}
> [  511.238564] 
> [  511.238564] ... which became RECLAIM_FS-irq-safe at:
> [  511.242078]   
> [  511.242084] [<ffffffff811089db>] __lock_acquire+0x34b/0x1640
> [  511.244495] [<ffffffff8110a119>] lock_acquire+0xc9/0x250
> [  511.246697] [<ffffffff813b3525>] jbd2_log_wait_commit+0x55/0x1d0
[...]
> [  511.276216] to a RECLAIM_FS-irq-unsafe lock:
> [  511.278128]  (cpu_hotplug.dep_map){++++++}
> [  511.278130] 
> [  511.278130] ... which became RECLAIM_FS-irq-unsafe at:
> [  511.281809] ...
> [  511.281811]   
> [  511.282598] [<ffffffff81108141>] mark_held_locks+0x71/0x90
> [  511.284854] [<ffffffff8110ab6f>] lockdep_trace_alloc+0x6f/0xd0
> [  511.287218] [<ffffffff812744c8>] kmem_cache_alloc_node_trace+0x48/0x3b0
> [  511.289755] [<ffffffff810cfa65>] __smpboot_create_thread.part.2+0x35/0xf0
> [  511.292329] [<ffffffff810d0026>] smpboot_create_threads+0x66/0x90
[...]
> [  511.317867] other info that might help us debug this:
> [  511.317867] 
> [  511.320920]  Possible interrupt unsafe locking scenario:
> [  511.320920] 
> [  511.323218]        CPU0                    CPU1
> [  511.324622]        ----                    ----
> [  511.325973]   lock(cpu_hotplug.dep_map);
> [  511.327246]                                local_irq_disable();
> [  511.328870]                                lock(jbd2_handle);
> [  511.330483]                                lock(cpu_hotplug.dep_map);
> [  511.332259]   <Interrupt>
> [  511.333187]     lock(jbd2_handle);

Peter, is there any way how to tell the lockdep that this is in fact
reclaim safe? The direct reclaim only does the trylock and backs off so
we cannot deadlock here.

Or am I misinterpreting the trace?
-- 
Michal Hocko
SUSE Labs

Back to linux.kernel | Previous | NextPrevious in thread | Next in thread | Find similar | Unroll thread


Thread

Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages  per zone Michal Hocko <mhocko@kernel.org> - 2017-02-02 11:20 +0100
  Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages per zone Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2017-02-03 12:10 +0100
    Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages  per zone Michal Hocko <mhocko@kernel.org> - 2017-02-03 15:50 +0100
    Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages  per zone Michal Hocko <mhocko@kernel.org> - 2017-02-03 16:00 +0100
      Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages  per zone Brian Foster <bfoster@redhat.com> - 2017-02-03 18:30 +0100
        Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages per zone Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2017-02-06 07:40 +0100
          Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages  per zone Brian Foster <bfoster@redhat.com> - 2017-02-06 15:40 +0100
            Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages  per zone Michal Hocko <mhocko@kernel.org> - 2017-02-06 15:50 +0100
              Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages  per zone Brian Foster <bfoster@redhat.com> - 2017-02-06 16:50 +0100
            Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages per zone Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2017-02-07 11:40 +0100
              Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages  per zone Brian Foster <bfoster@redhat.com> - 2017-02-07 18:00 +0100
    Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages  per zone Michal Hocko <mhocko@kernel.org> - 2017-02-03 16:00 +0100
      Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages per zone Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> - 2017-02-05 11:50 +0100
        Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages  per zone Michal Hocko <mhocko@kernel.org> - 2017-02-06 11:40 +0100
          Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages  per zone Michal Hocko <mhocko@kernel.org> - 2017-02-07 22:20 +0100
            Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages  per zone Peter Zijlstra <peterz@infradead.org> - 2017-02-08 10:50 +0100
        Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages  per zone Michal Hocko <mhocko@kernel.org> - 2017-02-06 11:40 +0100

csiph-web