From: Michal Hocko <mhocko@kernel.org>
To: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>, peterz@infradead.org
Cc: hch@lst.de, mgorman@suse.de, viro@ZenIV.linux.org.uk,
linux-mm@kvack.org, hannes@cmpxchg.org,
linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages per zone
Date: Tue, 7 Feb 2017 22:12:12 +0100 [thread overview]
Message-ID: <20170207211211.GB19351@dhcp22.suse.cz> (raw)
In-Reply-To: <20170206103918.GD3097@dhcp22.suse.cz>
On Mon 06-02-17 11:39:18, Michal Hocko wrote:
> 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?
This is moot - http://lkml.kernel.org/r/20170207201950.20482-1-mhocko@kernel.org
--
Michal Hocko
SUSE Labs
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next prev parent reply other threads:[~2017-02-07 21:12 UTC|newest]
Thread overview: 55+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-01-18 13:44 [RFC PATCH 0/2] fix unbounded too_many_isolated Michal Hocko
2017-01-18 13:44 ` [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages per zone Michal Hocko
2017-01-18 14:46 ` Mel Gorman
2017-01-18 15:15 ` Michal Hocko
2017-01-18 15:54 ` Mel Gorman
2017-01-18 16:17 ` Michal Hocko
2017-01-18 17:00 ` Mel Gorman
2017-01-18 17:29 ` Michal Hocko
2017-01-19 10:07 ` Mel Gorman
2017-01-19 11:23 ` Michal Hocko
2017-01-19 13:11 ` Mel Gorman
2017-01-20 13:27 ` Tetsuo Handa
2017-01-21 7:42 ` Tetsuo Handa
2017-01-25 10:15 ` Michal Hocko
2017-01-25 10:19 ` Christoph Hellwig
2017-01-25 10:46 ` Michal Hocko
2017-01-25 11:09 ` Tetsuo Handa
2017-01-25 13:00 ` Michal Hocko
2017-01-27 14:49 ` Michal Hocko
2017-01-28 15:27 ` Tetsuo Handa
2017-01-30 8:55 ` Michal Hocko
2017-02-02 10:14 ` Michal Hocko
2017-02-03 10:57 ` Tetsuo Handa
2017-02-03 14:41 ` Michal Hocko
2017-02-03 14:50 ` Michal Hocko
2017-02-03 17:24 ` Brian Foster
2017-02-06 6:29 ` Tetsuo Handa
2017-02-06 14:35 ` Brian Foster
2017-02-06 14:42 ` Michal Hocko
2017-02-06 15:47 ` Brian Foster
2017-02-07 10:30 ` Tetsuo Handa
2017-02-07 16:54 ` Brian Foster
2017-02-03 14:55 ` Michal Hocko
2017-02-05 10:43 ` Tetsuo Handa
2017-02-06 10:34 ` Michal Hocko
2017-02-06 10:39 ` Michal Hocko
2017-02-07 21:12 ` Michal Hocko [this message]
2017-02-08 9:24 ` Peter Zijlstra
2017-02-21 9:40 ` Michal Hocko
2017-02-21 14:35 ` Tetsuo Handa
2017-02-21 15:53 ` Michal Hocko
2017-02-22 2:02 ` Tetsuo Handa
2017-02-22 7:54 ` Michal Hocko
2017-02-26 6:30 ` Tetsuo Handa
2017-01-31 11:58 ` Michal Hocko
2017-01-31 12:51 ` Christoph Hellwig
2017-01-31 13:21 ` Michal Hocko
2017-01-25 10:33 ` [RFC PATCH 1/2] mm, vmscan: account the number of isolated pagesper zone Tetsuo Handa
2017-01-25 12:34 ` Michal Hocko
2017-01-25 13:13 ` [RFC PATCH 1/2] mm, vmscan: account the number of isolated pages per zone Tetsuo Handa
2017-01-25 9:53 ` Michal Hocko
2017-01-20 6:42 ` Hillf Danton
2017-01-20 9:25 ` Mel Gorman
2017-01-18 13:44 ` [RFC PATCH 2/2] mm, vmscan: do not loop on too_many_isolated for ever Michal Hocko
2017-01-18 14:50 ` Mel Gorman
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