* INFO: possible recursive locking detected: get_partial_node() on 3.2-rc1 [not found] <20111109090556.GA5949@zhy> @ 2011-11-10 23:35 ` Julie Sullivan 2011-11-11 3:04 ` Shaohua Li 0 siblings, 1 reply; 11+ messages in thread From: Julie Sullivan @ 2011-11-10 23:35 UTC (permalink / raw) To: Yong Zhang Cc: linux-kernel, Pekka Enberg, Paul E. McKenney, Thomas Gleixner, Christoph Lameter, linux-mm (was '3.2-rc1: INFO: possible recursive locking detect') On Wednesday 09 November 2011 09:05:57 Yong Zhang wrote: > >Hi, >Just get below waring when doing: >for i in `seq 1 10`; do ./perf bench -f simple sched messaging -g 40; done >And kernel config is attached. >Thanks, >Yong >--- >[ 350.148020] ============================================= [ 350.148020] [ INFO: possible recursive locking detected ] [ 350.148020] 3.2.0-rc1-10791-g76a4b59-dirty #2 [ 350.148020] --------------------------------------------- [ 350.148020] perf/9439 is trying to acquire lock: [ 350.148020] (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff8113847f>] get_partial_node+0x5f/0x360 [ 350.148020] [ 350.148020] but task is already holding lock: [ 350.148020] (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811380c9>] unfreeze_partials+0x199/0x3c0 [ 350.148020] [ 350.148020] other info that might help us debug this: [ 350.148020] Possible unsafe locking scenario: [ 350.148020] [ 350.148020] CPU0 [ 350.148020] ---- [ 350.148020] lock(&(&n->list_lock)->rlock); [ 350.148020] lock(&(&n->list_lock)->rlock); [ 350.148020] [ 350.148020] *** DEADLOCK *** [ 350.148020] [ 350.148020] May be due to missing lock nesting notation [ 350.148020] [ 350.148020] 2 locks held by perf/9439: [ 350.148020] #0: (tasklist_lock){.+.+..}, at: [<ffffffff810552ee>] release_task+0x9e/0x500 >[ 350.148020] #1: (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811380c9>] unfreeze_partials+0x199/0x3c0 Hi Yong I've been getting a similar report not when using perf though, just in my dmesg at startup: (if people want my .config please ask, I'm not including it else in case it's just unhelpful noise) Cheers Julie [ 34.545934] ============================================= [ 34.545936] [ INFO: possible recursive locking detected ] [ 34.545939] 3.2.0-rc1 #103 [ 34.545940] --------------------------------------------- [ 34.545943] kdeinit4/2559 is trying to acquire lock: [ 34.545945] (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff8110aaa4>] get_partial_node+0x3f/0x17a [ 34.545954] [ 34.545955] but task is already holding lock: [ 34.545957] (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff81109efe>] unfreeze_partials+0xc4/0x193 [ 34.545963] [ 34.545964] other info that might help us debug this: [ 34.545966] Possible unsafe locking scenario: [ 34.545966] [ 34.545968] CPU0 [ 34.545969] ---- [ 34.545971] lock(&(&n->list_lock)->rlock); [ 34.545974] lock(&(&n->list_lock)->rlock); [ 34.545977] [ 34.545978] *** DEADLOCK *** [ 34.545978] [ 34.545980] May be due to missing lock nesting notation [ 34.545981] [ 34.545983] 1 lock held by kdeinit4/2559: [ 34.545985] #0: (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff81109efe>] unfreeze_partials+0xc4/0x193 [ 34.545992] [ 34.545992] stack backtrace: [ 34.545995] Pid: 2559, comm: kdeinit4 Not tainted 3.2.0-rc1 #103 [ 34.545997] Call Trace: [ 34.546003] [<ffffffff81076548>] __lock_acquire+0x9d8/0xdf7 [ 34.546008] [<ffffffff8105fdf5>] ? __kernel_text_address+0x26/0x4c [ 34.546010] [<ffffffff81004c57>] ? print_context_stack+0x9c/0xb2 [ 34.546010] [<ffffffff8110aaa4>] ? get_partial_node+0x3f/0x17a [ 34.546010] [<ffffffff81076e4a>] lock_acquire+0xd8/0xfe [ 34.546010] [<ffffffff8110aaa4>] ? get_partial_node+0x3f/0x17a [ 34.546010] [<ffffffff8107e092>] ? __module_text_address+0x12/0x5f [ 34.546010] [<ffffffff815af2d3>] _raw_spin_lock+0x45/0x7a [ 34.546010] [<ffffffff8110aaa4>] ? get_partial_node+0x3f/0x17a [ 34.546010] [<ffffffff8110aaa4>] get_partial_node+0x3f/0x17a [ 34.546010] [<ffffffff810733fb>] ? look_up_lock_class+0x5f/0xbe [ 34.546010] [<ffffffff8107e092>] ? __module_text_address+0x12/0x5f [ 34.546010] [<ffffffff8110ad4e>] __slab_alloc+0x16f/0x3ae [ 34.546010] [<ffffffff81008529>] ? native_sched_clock+0x3b/0x3d [ 34.546010] [<ffffffff81112d46>] ? create_object+0x39/0x283 [ 34.546010] [<ffffffff81008529>] ? native_sched_clock+0x3b/0x3d [ 34.546010] [<ffffffff81072655>] ? arch_local_irq_save+0x9/0xc [ 34.546010] [<ffffffff81112d46>] ? create_object+0x39/0x283 [ 34.546010] [<ffffffff8110c54c>] kmem_cache_alloc+0x5b/0x12b [ 34.546010] [<ffffffff81112d46>] create_object+0x39/0x283 [ 34.546010] [<ffffffff8159655c>] kmemleak_alloc+0x73/0x98 [ 34.546010] [<ffffffff81250c3c>] ? __debug_object_init+0x43/0x2e7 [ 34.546010] [<ffffffff8110c5b4>] kmem_cache_alloc+0xc3/0x12b [ 34.546010] [<ffffffff810679c7>] ? sched_clock_local+0x12/0x75 [ 34.546010] [<ffffffff81250c3c>] __debug_object_init+0x43/0x2e7 [ 34.546010] [<ffffffff81067b92>] ? local_clock+0x2b/0x3c [ 34.546010] [<ffffffff81073b06>] ? lock_release_holdtime+0x59/0x60 [ 34.546010] [<ffffffff81250ef4>] debug_object_init+0x14/0x16 [ 34.546010] [<ffffffff8105fc57>] rcuhead_fixup_activate+0x27/0x5f [ 34.546010] [<ffffffff81250943>] debug_object_fixup+0x1e/0x2b [ 34.546010] [<ffffffff81250fdb>] debug_object_activate+0xcc/0xd9 [ 34.546010] [<ffffffff8110939f>] ? discard_slab+0x4e/0x4e [ 34.546010] [<ffffffff810a8b77>] __call_rcu+0x4f/0x18e [ 34.546010] [<ffffffff810a8ce2>] call_rcu_sched+0x15/0x17 [ 34.546010] [<ffffffff81109396>] discard_slab+0x45/0x4e [ 34.546010] [<ffffffff81109fa4>] unfreeze_partials+0x16a/0x193 [ 34.546010] [<ffffffff81073b06>] ? lock_release_holdtime+0x59/0x60 [ 34.546010] [<ffffffff815afd87>] ? _raw_spin_unlock_irqrestore+0x3f/0x55 [ 34.546010] [<ffffffff8110a020>] put_cpu_partial+0x53/0xbd [ 34.546010] [<ffffffff8110a197>] __slab_free+0x10d/0x229 [ 34.546010] [<ffffffff810f5e08>] ? anon_vma_free+0x3d/0x41 [ 34.546010] [<ffffffff810f5e08>] ? anon_vma_free+0x3d/0x41 [ 34.546010] [<ffffffff8110a44b>] kmem_cache_free+0x7d/0xc4 [ 34.546010] [<ffffffff810f5e08>] anon_vma_free+0x3d/0x41 [ 34.546010] [<ffffffff810f6d9e>] __put_anon_vma+0x38/0x3d [ 34.546010] [<ffffffff810f6dcc>] put_anon_vma+0x29/0x2d [ 34.546010] [<ffffffff810f6f28>] unlink_anon_vmas+0xf5/0x14c [ 34.546010] [<ffffffff815ae4c4>] ? mutex_unlock+0xe/0x10 [ 34.546010] [<ffffffff810ed096>] free_pgtables+0x73/0xd0 [ 34.546010] [<ffffffff810f30ad>] exit_mmap+0xac/0xe5 [ 34.546010] [<ffffffff81043d05>] mmput+0x60/0x108 [ 34.546010] [<ffffffff81048323>] exit_mm+0x119/0x126 [ 34.546010] [<ffffffff815afd34>] ? _raw_spin_unlock_irq+0x30/0x44 [ 34.546010] [<ffffffff81049a59>] do_exit+0x233/0x80f [ 34.546010] [<ffffffff81073330>] ? trace_hardirqs_off_caller+0x33/0x90 [ 34.546010] [<ffffffff815affca>] ? retint_swapgs+0xe/0x13 [ 34.546010] [<ffffffff8104a2dd>] do_group_exit+0x88/0xb6 [ 34.546010] [<ffffffff8104a322>] sys_exit_group+0x17/0x1b [ 34.546010] [<ffffffff815b662b>] system_call_fastpath+0x16/0x1b -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: INFO: possible recursive locking detected: get_partial_node() on 3.2-rc1 2011-11-10 23:35 ` INFO: possible recursive locking detected: get_partial_node() on 3.2-rc1 Julie Sullivan @ 2011-11-11 3:04 ` Shaohua Li 2011-11-11 4:42 ` Yong Zhang 2011-11-11 15:02 ` Christoph Lameter 0 siblings, 2 replies; 11+ messages in thread From: Shaohua Li @ 2011-11-11 3:04 UTC (permalink / raw) To: Julie Sullivan Cc: Yong Zhang, linux-kernel@vger.kernel.org, Pekka Enberg, Paul E. McKenney, Thomas Gleixner, Christoph Lameter, linux-mm@kvack.org On Fri, 2011-11-11 at 07:35 +0800, Julie Sullivan wrote: > (was '3.2-rc1: INFO: possible recursive locking detect') > > On Wednesday 09 November 2011 09:05:57 Yong Zhang wrote: > > > >Hi, > >Just get below waring when doing: > >for i in `seq 1 10`; do ./perf bench -f simple sched messaging -g 40; done > > >And kernel config is attached. Looks this could be a real dead lock. we hold a lock to free a object, but the free need allocate a new object. if the new object and the freed object are from the same slab, there is a deadlock. discard_slab() doesn't need hold the lock if the slab is already removed from partial list. how about below patch, only compile tested. diff --git a/mm/slub.c b/mm/slub.c index 7d2a996..9375668 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1858,7 +1858,7 @@ redo: } /* Unfreeze all the cpu partial slabs */ -static void unfreeze_partials(struct kmem_cache *s) +static void unfreeze_partials(struct kmem_cache *s, struct page **discard_page) { struct kmem_cache_node *n = NULL; struct kmem_cache_cpu *c = this_cpu_ptr(s->cpu_slab); @@ -1915,14 +1915,28 @@ static void unfreeze_partials(struct kmem_cache *s) "unfreezing slab")); if (m == M_FREE) { - stat(s, DEACTIVATE_EMPTY); - discard_slab(s, page); - stat(s, FREE_SLAB); + page->next = *discard_page; + *discard_page = page; } } if (n) spin_unlock(&n->list_lock); + +} + +static void discard_page_list(struct kmem_cache *s, struct page *discard_page) +{ + struct page *page; + + while (discard_page) { + page = discard_page; + discard_page = discard_page->next; + + stat(s, DEACTIVATE_EMPTY); + discard_slab(s, page); + stat(s, FREE_SLAB); + } } /* @@ -1950,13 +1964,15 @@ int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain) pages = oldpage->pages; if (drain && pobjects > s->cpu_partial) { unsigned long flags; + struct page *discard_page = NULL; /* * partial array is full. Move the existing * set to the per node partial list. */ local_irq_save(flags); - unfreeze_partials(s); + unfreeze_partials(s, &discard_page); local_irq_restore(flags); + discard_page_list(s, discard_page); pobjects = 0; pages = 0; } @@ -1988,12 +2004,14 @@ static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu) { struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu); + struct page *discard_page = NULL; if (likely(c)) { if (c->page) flush_slab(s, c); - unfreeze_partials(s); + unfreeze_partials(s, &discard_page); + discard_page_list(s, discard_page); } } > >--- > >[ 350.148020] ============================================= > [ 350.148020] [ INFO: possible recursive locking detected ] > [ 350.148020] 3.2.0-rc1-10791-g76a4b59-dirty #2 > [ 350.148020] --------------------------------------------- > [ 350.148020] perf/9439 is trying to acquire lock: > [ 350.148020] (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff8113847f>] get_partial_node+0x5f/0x360 > [ 350.148020] > [ 350.148020] but task is already holding lock: > [ 350.148020] (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811380c9>] unfreeze_partials+0x199/0x3c0 > [ 350.148020] > [ 350.148020] other info that might help us debug this: > [ 350.148020] Possible unsafe locking scenario: > [ 350.148020] > [ 350.148020] CPU0 > [ 350.148020] ---- > [ 350.148020] lock(&(&n->list_lock)->rlock); > [ 350.148020] lock(&(&n->list_lock)->rlock); > [ 350.148020] > [ 350.148020] *** DEADLOCK *** > [ 350.148020] > [ 350.148020] May be due to missing lock nesting notation > [ 350.148020] > [ 350.148020] 2 locks held by perf/9439: > [ 350.148020] #0: (tasklist_lock){.+.+..}, at: [<ffffffff810552ee>] release_task+0x9e/0x500 > >[ 350.148020] #1: (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811380c9>] unfreeze_partials+0x199/0x3c0 > > > Hi Yong > > I've been getting a similar report not when using perf though, just in my dmesg at startup: > (if people want my .config please ask, I'm not including it else in case it's just unhelpful noise) > > Cheers > Julie > > [ 34.545934] ============================================= > [ 34.545936] [ INFO: possible recursive locking detected ] > [ 34.545939] 3.2.0-rc1 #103 > [ 34.545940] --------------------------------------------- > [ 34.545943] kdeinit4/2559 is trying to acquire lock: > [ 34.545945] (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff8110aaa4>] get_partial_node+0x3f/0x17a > [ 34.545954] > [ 34.545955] but task is already holding lock: > [ 34.545957] (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff81109efe>] unfreeze_partials+0xc4/0x193 > [ 34.545963] > [ 34.545964] other info that might help us debug this: > [ 34.545966] Possible unsafe locking scenario: > [ 34.545966] > [ 34.545968] CPU0 > [ 34.545969] ---- > [ 34.545971] lock(&(&n->list_lock)->rlock); > [ 34.545974] lock(&(&n->list_lock)->rlock); > [ 34.545977] > [ 34.545978] *** DEADLOCK *** > [ 34.545978] > [ 34.545980] May be due to missing lock nesting notation > [ 34.545981] > [ 34.545983] 1 lock held by kdeinit4/2559: > [ 34.545985] #0: (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff81109efe>] unfreeze_partials+0xc4/0x193 > [ 34.545992] > [ 34.545992] stack backtrace: > [ 34.545995] Pid: 2559, comm: kdeinit4 Not tainted 3.2.0-rc1 #103 > [ 34.545997] Call Trace: > [ 34.546003] [<ffffffff81076548>] __lock_acquire+0x9d8/0xdf7 > [ 34.546008] [<ffffffff8105fdf5>] ? __kernel_text_address+0x26/0x4c > [ 34.546010] [<ffffffff81004c57>] ? print_context_stack+0x9c/0xb2 > [ 34.546010] [<ffffffff8110aaa4>] ? get_partial_node+0x3f/0x17a > [ 34.546010] [<ffffffff81076e4a>] lock_acquire+0xd8/0xfe > [ 34.546010] [<ffffffff8110aaa4>] ? get_partial_node+0x3f/0x17a > [ 34.546010] [<ffffffff8107e092>] ? __module_text_address+0x12/0x5f > [ 34.546010] [<ffffffff815af2d3>] _raw_spin_lock+0x45/0x7a > [ 34.546010] [<ffffffff8110aaa4>] ? get_partial_node+0x3f/0x17a > [ 34.546010] [<ffffffff8110aaa4>] get_partial_node+0x3f/0x17a > [ 34.546010] [<ffffffff810733fb>] ? look_up_lock_class+0x5f/0xbe > [ 34.546010] [<ffffffff8107e092>] ? __module_text_address+0x12/0x5f > [ 34.546010] [<ffffffff8110ad4e>] __slab_alloc+0x16f/0x3ae > [ 34.546010] [<ffffffff81008529>] ? native_sched_clock+0x3b/0x3d > [ 34.546010] [<ffffffff81112d46>] ? create_object+0x39/0x283 > [ 34.546010] [<ffffffff81008529>] ? native_sched_clock+0x3b/0x3d > [ 34.546010] [<ffffffff81072655>] ? arch_local_irq_save+0x9/0xc > [ 34.546010] [<ffffffff81112d46>] ? create_object+0x39/0x283 > [ 34.546010] [<ffffffff8110c54c>] kmem_cache_alloc+0x5b/0x12b > [ 34.546010] [<ffffffff81112d46>] create_object+0x39/0x283 > [ 34.546010] [<ffffffff8159655c>] kmemleak_alloc+0x73/0x98 > [ 34.546010] [<ffffffff81250c3c>] ? __debug_object_init+0x43/0x2e7 > [ 34.546010] [<ffffffff8110c5b4>] kmem_cache_alloc+0xc3/0x12b > [ 34.546010] [<ffffffff810679c7>] ? sched_clock_local+0x12/0x75 > [ 34.546010] [<ffffffff81250c3c>] __debug_object_init+0x43/0x2e7 > [ 34.546010] [<ffffffff81067b92>] ? local_clock+0x2b/0x3c > [ 34.546010] [<ffffffff81073b06>] ? lock_release_holdtime+0x59/0x60 > [ 34.546010] [<ffffffff81250ef4>] debug_object_init+0x14/0x16 > [ 34.546010] [<ffffffff8105fc57>] rcuhead_fixup_activate+0x27/0x5f > [ 34.546010] [<ffffffff81250943>] debug_object_fixup+0x1e/0x2b > [ 34.546010] [<ffffffff81250fdb>] debug_object_activate+0xcc/0xd9 > [ 34.546010] [<ffffffff8110939f>] ? discard_slab+0x4e/0x4e > [ 34.546010] [<ffffffff810a8b77>] __call_rcu+0x4f/0x18e > [ 34.546010] [<ffffffff810a8ce2>] call_rcu_sched+0x15/0x17 > [ 34.546010] [<ffffffff81109396>] discard_slab+0x45/0x4e > [ 34.546010] [<ffffffff81109fa4>] unfreeze_partials+0x16a/0x193 > [ 34.546010] [<ffffffff81073b06>] ? lock_release_holdtime+0x59/0x60 > [ 34.546010] [<ffffffff815afd87>] ? _raw_spin_unlock_irqrestore+0x3f/0x55 > [ 34.546010] [<ffffffff8110a020>] put_cpu_partial+0x53/0xbd > [ 34.546010] [<ffffffff8110a197>] __slab_free+0x10d/0x229 > [ 34.546010] [<ffffffff810f5e08>] ? anon_vma_free+0x3d/0x41 > [ 34.546010] [<ffffffff810f5e08>] ? anon_vma_free+0x3d/0x41 > [ 34.546010] [<ffffffff8110a44b>] kmem_cache_free+0x7d/0xc4 > [ 34.546010] [<ffffffff810f5e08>] anon_vma_free+0x3d/0x41 > [ 34.546010] [<ffffffff810f6d9e>] __put_anon_vma+0x38/0x3d > [ 34.546010] [<ffffffff810f6dcc>] put_anon_vma+0x29/0x2d > [ 34.546010] [<ffffffff810f6f28>] unlink_anon_vmas+0xf5/0x14c > [ 34.546010] [<ffffffff815ae4c4>] ? mutex_unlock+0xe/0x10 > [ 34.546010] [<ffffffff810ed096>] free_pgtables+0x73/0xd0 > [ 34.546010] [<ffffffff810f30ad>] exit_mmap+0xac/0xe5 > [ 34.546010] [<ffffffff81043d05>] mmput+0x60/0x108 > [ 34.546010] [<ffffffff81048323>] exit_mm+0x119/0x126 > [ 34.546010] [<ffffffff815afd34>] ? _raw_spin_unlock_irq+0x30/0x44 > [ 34.546010] [<ffffffff81049a59>] do_exit+0x233/0x80f > [ 34.546010] [<ffffffff81073330>] ? trace_hardirqs_off_caller+0x33/0x90 > [ 34.546010] [<ffffffff815affca>] ? retint_swapgs+0xe/0x13 > [ 34.546010] [<ffffffff8104a2dd>] do_group_exit+0x88/0xb6 > [ 34.546010] [<ffffffff8104a322>] sys_exit_group+0x17/0x1b > [ 34.546010] [<ffffffff815b662b>] system_call_fastpath+0x16/0x1b > > > > > -- > To unsubscribe, send a message with 'unsubscribe linux-mm' in > the body to majordomo@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: INFO: possible recursive locking detected: get_partial_node() on 3.2-rc1 2011-11-11 3:04 ` Shaohua Li @ 2011-11-11 4:42 ` Yong Zhang 2011-11-11 14:57 ` Christoph Lameter 2011-11-11 15:02 ` Christoph Lameter 1 sibling, 1 reply; 11+ messages in thread From: Yong Zhang @ 2011-11-11 4:42 UTC (permalink / raw) To: Shaohua Li Cc: Julie Sullivan, linux-kernel@vger.kernel.org, Pekka Enberg, Paul E. McKenney, Thomas Gleixner, Christoph Lameter, linux-mm@kvack.org On Fri, Nov 11, 2011 at 11:04:31AM +0800, Shaohua Li wrote: > On Fri, 2011-11-11 at 07:35 +0800, Julie Sullivan wrote: > > (was '3.2-rc1: INFO: possible recursive locking detect') > > > > On Wednesday 09 November 2011 09:05:57 Yong Zhang wrote: > > > > > >Hi, > > >Just get below waring when doing: > > >for i in `seq 1 10`; do ./perf bench -f simple sched messaging -g 40; done > > > > >And kernel config is attached. > > Looks this could be a real dead lock. we hold a lock to free a object, > but the free need allocate a new object. if the new object and the freed > object are from the same slab, there is a deadlock. > > discard_slab() doesn't need hold the lock if the slab is already removed > from partial list. how about below patch, only compile tested. It work on my side. Thanks, Yong > > diff --git a/mm/slub.c b/mm/slub.c > index 7d2a996..9375668 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -1858,7 +1858,7 @@ redo: > } > > /* Unfreeze all the cpu partial slabs */ > -static void unfreeze_partials(struct kmem_cache *s) > +static void unfreeze_partials(struct kmem_cache *s, struct page **discard_page) > { > struct kmem_cache_node *n = NULL; > struct kmem_cache_cpu *c = this_cpu_ptr(s->cpu_slab); > @@ -1915,14 +1915,28 @@ static void unfreeze_partials(struct kmem_cache *s) > "unfreezing slab")); > > if (m == M_FREE) { > - stat(s, DEACTIVATE_EMPTY); > - discard_slab(s, page); > - stat(s, FREE_SLAB); > + page->next = *discard_page; > + *discard_page = page; > } > } > > if (n) > spin_unlock(&n->list_lock); > + > +} > + > +static void discard_page_list(struct kmem_cache *s, struct page *discard_page) > +{ > + struct page *page; > + > + while (discard_page) { > + page = discard_page; > + discard_page = discard_page->next; > + > + stat(s, DEACTIVATE_EMPTY); > + discard_slab(s, page); > + stat(s, FREE_SLAB); > + } > } > > /* > @@ -1950,13 +1964,15 @@ int put_cpu_partial(struct kmem_cache *s, struct page *page, int drain) > pages = oldpage->pages; > if (drain && pobjects > s->cpu_partial) { > unsigned long flags; > + struct page *discard_page = NULL; > /* > * partial array is full. Move the existing > * set to the per node partial list. > */ > local_irq_save(flags); > - unfreeze_partials(s); > + unfreeze_partials(s, &discard_page); > local_irq_restore(flags); > + discard_page_list(s, discard_page); > pobjects = 0; > pages = 0; > } > @@ -1988,12 +2004,14 @@ static inline void flush_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) > static inline void __flush_cpu_slab(struct kmem_cache *s, int cpu) > { > struct kmem_cache_cpu *c = per_cpu_ptr(s->cpu_slab, cpu); > + struct page *discard_page = NULL; > > if (likely(c)) { > if (c->page) > flush_slab(s, c); > > - unfreeze_partials(s); > + unfreeze_partials(s, &discard_page); > + discard_page_list(s, discard_page); > } > } > > > > > >--- > > >[ 350.148020] ============================================= > > [ 350.148020] [ INFO: possible recursive locking detected ] > > [ 350.148020] 3.2.0-rc1-10791-g76a4b59-dirty #2 > > [ 350.148020] --------------------------------------------- > > [ 350.148020] perf/9439 is trying to acquire lock: > > [ 350.148020] (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff8113847f>] get_partial_node+0x5f/0x360 > > [ 350.148020] > > [ 350.148020] but task is already holding lock: > > [ 350.148020] (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811380c9>] unfreeze_partials+0x199/0x3c0 > > [ 350.148020] > > [ 350.148020] other info that might help us debug this: > > [ 350.148020] Possible unsafe locking scenario: > > [ 350.148020] > > [ 350.148020] CPU0 > > [ 350.148020] ---- > > [ 350.148020] lock(&(&n->list_lock)->rlock); > > [ 350.148020] lock(&(&n->list_lock)->rlock); > > [ 350.148020] > > [ 350.148020] *** DEADLOCK *** > > [ 350.148020] > > [ 350.148020] May be due to missing lock nesting notation > > [ 350.148020] > > [ 350.148020] 2 locks held by perf/9439: > > [ 350.148020] #0: (tasklist_lock){.+.+..}, at: [<ffffffff810552ee>] release_task+0x9e/0x500 > > >[ 350.148020] #1: (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff811380c9>] unfreeze_partials+0x199/0x3c0 > > > > > > Hi Yong > > > > I've been getting a similar report not when using perf though, just in my dmesg at startup: > > (if people want my .config please ask, I'm not including it else in case it's just unhelpful noise) > > > > Cheers > > Julie > > > > [ 34.545934] ============================================= > > [ 34.545936] [ INFO: possible recursive locking detected ] > > [ 34.545939] 3.2.0-rc1 #103 > > [ 34.545940] --------------------------------------------- > > [ 34.545943] kdeinit4/2559 is trying to acquire lock: > > [ 34.545945] (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff8110aaa4>] get_partial_node+0x3f/0x17a > > [ 34.545954] > > [ 34.545955] but task is already holding lock: > > [ 34.545957] (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff81109efe>] unfreeze_partials+0xc4/0x193 > > [ 34.545963] > > [ 34.545964] other info that might help us debug this: > > [ 34.545966] Possible unsafe locking scenario: > > [ 34.545966] > > [ 34.545968] CPU0 > > [ 34.545969] ---- > > [ 34.545971] lock(&(&n->list_lock)->rlock); > > [ 34.545974] lock(&(&n->list_lock)->rlock); > > [ 34.545977] > > [ 34.545978] *** DEADLOCK *** > > [ 34.545978] > > [ 34.545980] May be due to missing lock nesting notation > > [ 34.545981] > > [ 34.545983] 1 lock held by kdeinit4/2559: > > [ 34.545985] #0: (&(&n->list_lock)->rlock){-.-...}, at: [<ffffffff81109efe>] unfreeze_partials+0xc4/0x193 > > [ 34.545992] > > [ 34.545992] stack backtrace: > > [ 34.545995] Pid: 2559, comm: kdeinit4 Not tainted 3.2.0-rc1 #103 > > [ 34.545997] Call Trace: > > [ 34.546003] [<ffffffff81076548>] __lock_acquire+0x9d8/0xdf7 > > [ 34.546008] [<ffffffff8105fdf5>] ? __kernel_text_address+0x26/0x4c > > [ 34.546010] [<ffffffff81004c57>] ? print_context_stack+0x9c/0xb2 > > [ 34.546010] [<ffffffff8110aaa4>] ? get_partial_node+0x3f/0x17a > > [ 34.546010] [<ffffffff81076e4a>] lock_acquire+0xd8/0xfe > > [ 34.546010] [<ffffffff8110aaa4>] ? get_partial_node+0x3f/0x17a > > [ 34.546010] [<ffffffff8107e092>] ? __module_text_address+0x12/0x5f > > [ 34.546010] [<ffffffff815af2d3>] _raw_spin_lock+0x45/0x7a > > [ 34.546010] [<ffffffff8110aaa4>] ? get_partial_node+0x3f/0x17a > > [ 34.546010] [<ffffffff8110aaa4>] get_partial_node+0x3f/0x17a > > [ 34.546010] [<ffffffff810733fb>] ? look_up_lock_class+0x5f/0xbe > > [ 34.546010] [<ffffffff8107e092>] ? __module_text_address+0x12/0x5f > > [ 34.546010] [<ffffffff8110ad4e>] __slab_alloc+0x16f/0x3ae > > [ 34.546010] [<ffffffff81008529>] ? native_sched_clock+0x3b/0x3d > > [ 34.546010] [<ffffffff81112d46>] ? create_object+0x39/0x283 > > [ 34.546010] [<ffffffff81008529>] ? native_sched_clock+0x3b/0x3d > > [ 34.546010] [<ffffffff81072655>] ? arch_local_irq_save+0x9/0xc > > [ 34.546010] [<ffffffff81112d46>] ? create_object+0x39/0x283 > > [ 34.546010] [<ffffffff8110c54c>] kmem_cache_alloc+0x5b/0x12b > > [ 34.546010] [<ffffffff81112d46>] create_object+0x39/0x283 > > [ 34.546010] [<ffffffff8159655c>] kmemleak_alloc+0x73/0x98 > > [ 34.546010] [<ffffffff81250c3c>] ? __debug_object_init+0x43/0x2e7 > > [ 34.546010] [<ffffffff8110c5b4>] kmem_cache_alloc+0xc3/0x12b > > [ 34.546010] [<ffffffff810679c7>] ? sched_clock_local+0x12/0x75 > > [ 34.546010] [<ffffffff81250c3c>] __debug_object_init+0x43/0x2e7 > > [ 34.546010] [<ffffffff81067b92>] ? local_clock+0x2b/0x3c > > [ 34.546010] [<ffffffff81073b06>] ? lock_release_holdtime+0x59/0x60 > > [ 34.546010] [<ffffffff81250ef4>] debug_object_init+0x14/0x16 > > [ 34.546010] [<ffffffff8105fc57>] rcuhead_fixup_activate+0x27/0x5f > > [ 34.546010] [<ffffffff81250943>] debug_object_fixup+0x1e/0x2b > > [ 34.546010] [<ffffffff81250fdb>] debug_object_activate+0xcc/0xd9 > > [ 34.546010] [<ffffffff8110939f>] ? discard_slab+0x4e/0x4e > > [ 34.546010] [<ffffffff810a8b77>] __call_rcu+0x4f/0x18e > > [ 34.546010] [<ffffffff810a8ce2>] call_rcu_sched+0x15/0x17 > > [ 34.546010] [<ffffffff81109396>] discard_slab+0x45/0x4e > > [ 34.546010] [<ffffffff81109fa4>] unfreeze_partials+0x16a/0x193 > > [ 34.546010] [<ffffffff81073b06>] ? lock_release_holdtime+0x59/0x60 > > [ 34.546010] [<ffffffff815afd87>] ? _raw_spin_unlock_irqrestore+0x3f/0x55 > > [ 34.546010] [<ffffffff8110a020>] put_cpu_partial+0x53/0xbd > > [ 34.546010] [<ffffffff8110a197>] __slab_free+0x10d/0x229 > > [ 34.546010] [<ffffffff810f5e08>] ? anon_vma_free+0x3d/0x41 > > [ 34.546010] [<ffffffff810f5e08>] ? anon_vma_free+0x3d/0x41 > > [ 34.546010] [<ffffffff8110a44b>] kmem_cache_free+0x7d/0xc4 > > [ 34.546010] [<ffffffff810f5e08>] anon_vma_free+0x3d/0x41 > > [ 34.546010] [<ffffffff810f6d9e>] __put_anon_vma+0x38/0x3d > > [ 34.546010] [<ffffffff810f6dcc>] put_anon_vma+0x29/0x2d > > [ 34.546010] [<ffffffff810f6f28>] unlink_anon_vmas+0xf5/0x14c > > [ 34.546010] [<ffffffff815ae4c4>] ? mutex_unlock+0xe/0x10 > > [ 34.546010] [<ffffffff810ed096>] free_pgtables+0x73/0xd0 > > [ 34.546010] [<ffffffff810f30ad>] exit_mmap+0xac/0xe5 > > [ 34.546010] [<ffffffff81043d05>] mmput+0x60/0x108 > > [ 34.546010] [<ffffffff81048323>] exit_mm+0x119/0x126 > > [ 34.546010] [<ffffffff815afd34>] ? _raw_spin_unlock_irq+0x30/0x44 > > [ 34.546010] [<ffffffff81049a59>] do_exit+0x233/0x80f > > [ 34.546010] [<ffffffff81073330>] ? trace_hardirqs_off_caller+0x33/0x90 > > [ 34.546010] [<ffffffff815affca>] ? retint_swapgs+0xe/0x13 > > [ 34.546010] [<ffffffff8104a2dd>] do_group_exit+0x88/0xb6 > > [ 34.546010] [<ffffffff8104a322>] sys_exit_group+0x17/0x1b > > [ 34.546010] [<ffffffff815b662b>] system_call_fastpath+0x16/0x1b > > > > > > > > > > -- > > To unsubscribe, send a message with 'unsubscribe linux-mm' in > > the body to majordomo@kvack.org. For more info on Linux MM, > > see: http://www.linux-mm.org/ . > > Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ > > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Only stand for myself -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: INFO: possible recursive locking detected: get_partial_node() on 3.2-rc1 2011-11-11 4:42 ` Yong Zhang @ 2011-11-11 14:57 ` Christoph Lameter 0 siblings, 0 replies; 11+ messages in thread From: Christoph Lameter @ 2011-11-11 14:57 UTC (permalink / raw) To: Yong Zhang Cc: Shaohua Li, Julie Sullivan, linux-kernel@vger.kernel.org, Pekka Enberg, Paul E. McKenney, Thomas Gleixner, linux-mm@kvack.org Looks like a false positive. put_cpu_partial() can be called with a parameter to indicate if draining of the per cpu partial list should be allowed ("drain"). Draining requires taking the list lock. "drain" is set to 0 when called from get_partial_node() (where we are already holding the list lock) so no deadlock should be possible. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: INFO: possible recursive locking detected: get_partial_node() on 3.2-rc1 2011-11-11 3:04 ` Shaohua Li 2011-11-11 4:42 ` Yong Zhang @ 2011-11-11 15:02 ` Christoph Lameter 2011-11-11 19:09 ` Julie Sullivan 2011-11-14 5:34 ` Shaohua Li 1 sibling, 2 replies; 11+ messages in thread From: Christoph Lameter @ 2011-11-11 15:02 UTC (permalink / raw) To: Shaohua Li Cc: Julie Sullivan, Yong Zhang, linux-kernel@vger.kernel.org, Pekka Enberg, Paul E. McKenney, Thomas Gleixner, linux-mm@kvack.org On Fri, 11 Nov 2011, Shaohua Li wrote: > Looks this could be a real dead lock. we hold a lock to free a object, > but the free need allocate a new object. if the new object and the freed > object are from the same slab, there is a deadlock. unfreeze partials is never called when going through get_partial_node() so there is no deadlock AFAICT. > discard_slab() doesn't need hold the lock if the slab is already removed > from partial list. how about below patch, only compile tested. In general I think it is good to move the call to discard_slab() out from under the list_lock in unfreeze_partials(). Could you fold discard_page_list into unfreeze_partials()? __flush_cpu_slab still calls discard_page_list with disabled interrupts even after your patch. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: INFO: possible recursive locking detected: get_partial_node() on 3.2-rc1 2011-11-11 15:02 ` Christoph Lameter @ 2011-11-11 19:09 ` Julie Sullivan 2011-11-11 19:22 ` Paul E. McKenney 2011-11-14 5:34 ` Shaohua Li 1 sibling, 1 reply; 11+ messages in thread From: Julie Sullivan @ 2011-11-11 19:09 UTC (permalink / raw) To: Christoph Lameter Cc: Shaohua Li, Yong Zhang, linux-kernel@vger.kernel.org, Pekka Enberg, Paul E. McKenney, Thomas Gleixner, linux-mm@kvack.org It's probably moot now but FWIW I checked Shaohua's patch too and it got rid of the warning in my dmesg. Cheers Julie -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: INFO: possible recursive locking detected: get_partial_node() on 3.2-rc1 2011-11-11 19:09 ` Julie Sullivan @ 2011-11-11 19:22 ` Paul E. McKenney 0 siblings, 0 replies; 11+ messages in thread From: Paul E. McKenney @ 2011-11-11 19:22 UTC (permalink / raw) To: Julie Sullivan Cc: Christoph Lameter, Shaohua Li, Yong Zhang, linux-kernel@vger.kernel.org, Pekka Enberg, Thomas Gleixner, linux-mm@kvack.org On Fri, Nov 11, 2011 at 07:09:01PM +0000, Julie Sullivan wrote: > It's probably moot now but FWIW I checked Shaohua's patch too and it > got rid of the warning in my dmesg. Thank you both for your testing efforts! Hopefully there will be a more permanent fix soon. Thanx, Paul -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: INFO: possible recursive locking detected: get_partial_node() on 3.2-rc1 2011-11-11 15:02 ` Christoph Lameter 2011-11-11 19:09 ` Julie Sullivan @ 2011-11-14 5:34 ` Shaohua Li 2011-11-15 7:22 ` Yong Zhang 2011-11-15 16:02 ` Christoph Lameter 1 sibling, 2 replies; 11+ messages in thread From: Shaohua Li @ 2011-11-14 5:34 UTC (permalink / raw) To: Christoph Lameter Cc: Julie Sullivan, Yong Zhang, linux-kernel@vger.kernel.org, Pekka Enberg, Paul E. McKenney, Thomas Gleixner, linux-mm@kvack.org On Fri, 2011-11-11 at 23:02 +0800, Christoph Lameter wrote: > On Fri, 11 Nov 2011, Shaohua Li wrote: > > > Looks this could be a real dead lock. we hold a lock to free a object, > > but the free need allocate a new object. if the new object and the freed > > object are from the same slab, there is a deadlock. > > unfreeze partials is never called when going through get_partial_node() > so there is no deadlock AFAICT. the unfreeze_partial isn't called from get_partial_node(). I thought the code path is something like this: kmem_cache_free()->put_cpu_partial() (hold lock) ->unfreeze_partials() ->discard_slab ->debug_object_init() ->kmem_cache_alloc->get_partial_node()(hold lock). Not sure if this will really happen, but looks like a deadlock. But anyway, discard_slab() can be move out of unfreeze_partials() > > discard_slab() doesn't need hold the lock if the slab is already removed > > from partial list. how about below patch, only compile tested. > > In general I think it is good to move the call to discard_slab() out from > under the list_lock in unfreeze_partials(). Could you fold > discard_page_list into unfreeze_partials()? __flush_cpu_slab still calls > discard_page_list with disabled interrupts even after your patch. I'm afraid there is alloc-in-atomic() error, but Yong & Julie's test shows this is over thinking. Here is the updated patch. Yong & Julie, I added your report/test by, because the new patch should be just like the old one, but since I changed it a little bit, can you please have a quick check? Thanks! Subject: slub: move discard_slab out of node lock Lockdep reports there is potential deadlock for slub node list_lock. discard_slab() is called with the lock hold in unfreeze_partials(), which could trigger a slab allocation, which could hold the lock again. discard_slab() doesn't need hold the lock actually, if the slab is already removed from partial list. Reported-and-tested-by: Yong Zhang <yong.zhang0@gmail.com> Reported-and-tested-by: Julie Sullivan <kernelmail.jms@gmail.com> Signed-off-by: Shaohua Li <shaohua.li@intel.com> --- mm/slub.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) Index: linux/mm/slub.c =================================================================== --- linux.orig/mm/slub.c 2011-11-11 16:17:39.000000000 +0800 +++ linux/mm/slub.c 2011-11-14 13:11:11.000000000 +0800 @@ -1862,7 +1862,7 @@ static void unfreeze_partials(struct kme { struct kmem_cache_node *n = NULL; struct kmem_cache_cpu *c = this_cpu_ptr(s->cpu_slab); - struct page *page; + struct page *page, *discard_page = NULL; while ((page = c->partial)) { enum slab_modes { M_PARTIAL, M_FREE }; @@ -1916,14 +1916,22 @@ static void unfreeze_partials(struct kme "unfreezing slab")); if (m == M_FREE) { - stat(s, DEACTIVATE_EMPTY); - discard_slab(s, page); - stat(s, FREE_SLAB); + page->next = discard_page; + discard_page = page; } } if (n) spin_unlock(&n->list_lock); + + while (discard_page) { + page = discard_page; + discard_page = discard_page->next; + + stat(s, DEACTIVATE_EMPTY); + discard_slab(s, page); + stat(s, FREE_SLAB); + } } /* -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: INFO: possible recursive locking detected: get_partial_node() on 3.2-rc1 2011-11-14 5:34 ` Shaohua Li @ 2011-11-15 7:22 ` Yong Zhang 2011-11-15 18:49 ` Pekka Enberg 2011-11-15 16:02 ` Christoph Lameter 1 sibling, 1 reply; 11+ messages in thread From: Yong Zhang @ 2011-11-15 7:22 UTC (permalink / raw) To: Shaohua Li Cc: Christoph Lameter, Julie Sullivan, linux-kernel@vger.kernel.org, Pekka Enberg, Paul E. McKenney, Thomas Gleixner, linux-mm@kvack.org On Mon, Nov 14, 2011 at 01:34:13PM +0800, Shaohua Li wrote: > On Fri, 2011-11-11 at 23:02 +0800, Christoph Lameter wrote: > > On Fri, 11 Nov 2011, Shaohua Li wrote: > > > > > Looks this could be a real dead lock. we hold a lock to free a object, > > > but the free need allocate a new object. if the new object and the freed > > > object are from the same slab, there is a deadlock. > > > > unfreeze partials is never called when going through get_partial_node() > > so there is no deadlock AFAICT. > the unfreeze_partial isn't called from get_partial_node(). I thought the > code path is something like this: kmem_cache_free()->put_cpu_partial() > (hold lock) ->unfreeze_partials() ->discard_slab ->debug_object_init() > ->kmem_cache_alloc->get_partial_node()(hold lock). Not sure if this will > really happen, but looks like a deadlock. > But anyway, discard_slab() can be move out of unfreeze_partials() > > > > discard_slab() doesn't need hold the lock if the slab is already removed > > > from partial list. how about below patch, only compile tested. > > > > In general I think it is good to move the call to discard_slab() out from > > under the list_lock in unfreeze_partials(). Could you fold > > discard_page_list into unfreeze_partials()? __flush_cpu_slab still calls > > discard_page_list with disabled interrupts even after your patch. > I'm afraid there is alloc-in-atomic() error, but Yong & Julie's test > shows this is over thinking. Here is the updated patch. Yong & Julie, I > added your report/test by, because the new patch should be just like the > old one, but since I changed it a little bit, can you please have a > quick check? Thanks! > > > > Subject: slub: move discard_slab out of node lock > > Lockdep reports there is potential deadlock for slub node list_lock. > discard_slab() is called with the lock hold in unfreeze_partials(), > which could trigger a slab allocation, which could hold the lock again. > > discard_slab() doesn't need hold the lock actually, if the slab is > already removed from partial list. > > Reported-and-tested-by: Yong Zhang <yong.zhang0@gmail.com> > Reported-and-tested-by: Julie Sullivan <kernelmail.jms@gmail.com> > Signed-off-by: Shaohua Li <shaohua.li@intel.com> Tested-by: Yong Zhang <yong.zhang0@gmail.com> Thanks, Yong > --- > mm/slub.c | 16 ++++++++++++---- > 1 file changed, 12 insertions(+), 4 deletions(-) > > Index: linux/mm/slub.c > =================================================================== > --- linux.orig/mm/slub.c 2011-11-11 16:17:39.000000000 +0800 > +++ linux/mm/slub.c 2011-11-14 13:11:11.000000000 +0800 > @@ -1862,7 +1862,7 @@ static void unfreeze_partials(struct kme > { > struct kmem_cache_node *n = NULL; > struct kmem_cache_cpu *c = this_cpu_ptr(s->cpu_slab); > - struct page *page; > + struct page *page, *discard_page = NULL; > > while ((page = c->partial)) { > enum slab_modes { M_PARTIAL, M_FREE }; > @@ -1916,14 +1916,22 @@ static void unfreeze_partials(struct kme > "unfreezing slab")); > > if (m == M_FREE) { > - stat(s, DEACTIVATE_EMPTY); > - discard_slab(s, page); > - stat(s, FREE_SLAB); > + page->next = discard_page; > + discard_page = page; > } > } > > if (n) > spin_unlock(&n->list_lock); > + > + while (discard_page) { > + page = discard_page; > + discard_page = discard_page->next; > + > + stat(s, DEACTIVATE_EMPTY); > + discard_slab(s, page); > + stat(s, FREE_SLAB); > + } > } > > /* > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Only stand for myself -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: INFO: possible recursive locking detected: get_partial_node() on 3.2-rc1 2011-11-15 7:22 ` Yong Zhang @ 2011-11-15 18:49 ` Pekka Enberg 0 siblings, 0 replies; 11+ messages in thread From: Pekka Enberg @ 2011-11-15 18:49 UTC (permalink / raw) To: Yong Zhang Cc: Shaohua Li, Christoph Lameter, Julie Sullivan, linux-kernel@vger.kernel.org, Paul E. McKenney, Thomas Gleixner, linux-mm@kvack.org On Tue, 15 Nov 2011, Yong Zhang wrote: >> Subject: slub: move discard_slab out of node lock >> >> Lockdep reports there is potential deadlock for slub node list_lock. >> discard_slab() is called with the lock hold in unfreeze_partials(), >> which could trigger a slab allocation, which could hold the lock again. >> >> discard_slab() doesn't need hold the lock actually, if the slab is >> already removed from partial list. >> >> Reported-and-tested-by: Yong Zhang <yong.zhang0@gmail.com> >> Reported-and-tested-by: Julie Sullivan <kernelmail.jms@gmail.com> >> Signed-off-by: Shaohua Li <shaohua.li@intel.com> > > Tested-by: Yong Zhang <yong.zhang0@gmail.com> Applied, thanks! -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: INFO: possible recursive locking detected: get_partial_node() on 3.2-rc1 2011-11-14 5:34 ` Shaohua Li 2011-11-15 7:22 ` Yong Zhang @ 2011-11-15 16:02 ` Christoph Lameter 1 sibling, 0 replies; 11+ messages in thread From: Christoph Lameter @ 2011-11-15 16:02 UTC (permalink / raw) To: Shaohua Li Cc: Julie Sullivan, Yong Zhang, linux-kernel@vger.kernel.org, Pekka Enberg, Paul E. McKenney, Thomas Gleixner, linux-mm@kvack.org Acked-by: Christoph Lameter <cl@linux.com> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2011-11-15 18:49 UTC | newest]
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2011-11-10 23:35 ` INFO: possible recursive locking detected: get_partial_node() on 3.2-rc1 Julie Sullivan
2011-11-11 3:04 ` Shaohua Li
2011-11-11 4:42 ` Yong Zhang
2011-11-11 14:57 ` Christoph Lameter
2011-11-11 15:02 ` Christoph Lameter
2011-11-11 19:09 ` Julie Sullivan
2011-11-11 19:22 ` Paul E. McKenney
2011-11-14 5:34 ` Shaohua Li
2011-11-15 7:22 ` Yong Zhang
2011-11-15 18:49 ` Pekka Enberg
2011-11-15 16:02 ` Christoph Lameter
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