112 lines
3.4 KiB
Diff
112 lines
3.4 KiB
Diff
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From 60efec9d4342a3b6930882da022585c2fd6b0b2a Mon Sep 17 00:00:00 2001
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From: Mike Galbraith <umgwanakikbuti@gmail.com>
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Date: Sat, 21 Jun 2014 10:09:48 +0200
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Subject: [PATCH 317/365] memcontrol: Prevent scheduling while atomic in cgroup
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code
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mm, memcg: make refill_stock() use get_cpu_light()
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Nikita reported the following memcg scheduling while atomic bug:
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Call Trace:
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[e22d5a90] [c0007ea8] show_stack+0x4c/0x168 (unreliable)
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[e22d5ad0] [c0618c04] __schedule_bug+0x94/0xb0
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[e22d5ae0] [c060b9ec] __schedule+0x530/0x550
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[e22d5bf0] [c060bacc] schedule+0x30/0xbc
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[e22d5c00] [c060ca24] rt_spin_lock_slowlock+0x180/0x27c
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[e22d5c70] [c00b39dc] res_counter_uncharge_until+0x40/0xc4
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[e22d5ca0] [c013ca88] drain_stock.isra.20+0x54/0x98
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[e22d5cc0] [c01402ac] __mem_cgroup_try_charge+0x2e8/0xbac
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[e22d5d70] [c01410d4] mem_cgroup_charge_common+0x3c/0x70
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[e22d5d90] [c0117284] __do_fault+0x38c/0x510
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[e22d5df0] [c011a5f4] handle_pte_fault+0x98/0x858
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[e22d5e50] [c060ed08] do_page_fault+0x42c/0x6fc
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[e22d5f40] [c000f5b4] handle_page_fault+0xc/0x80
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What happens:
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refill_stock()
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get_cpu_var()
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drain_stock()
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res_counter_uncharge()
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res_counter_uncharge_until()
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spin_lock() <== boom
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Fix it by replacing get/put_cpu_var() with get/put_cpu_light().
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Reported-by: Nikita Yushchenko <nyushchenko@dev.rtsoft.ru>
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Signed-off-by: Mike Galbraith <umgwanakikbuti@gmail.com>
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[bigeasy: use memcg_stock_ll as a locallock since it is now IRQ-off region]
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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mm/memcontrol.c | 13 +++++++------
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1 file changed, 7 insertions(+), 6 deletions(-)
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diff --git a/mm/memcontrol.c b/mm/memcontrol.c
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index 1c39495b1677..106918b6b30b 100644
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--- a/mm/memcontrol.c
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+++ b/mm/memcontrol.c
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@@ -1717,6 +1717,7 @@ struct memcg_stock_pcp {
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#define FLUSHING_CACHED_CHARGE 0
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};
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static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock);
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+static DEFINE_LOCAL_IRQ_LOCK(memcg_stock_ll);
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static DEFINE_MUTEX(percpu_charge_mutex);
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/**
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@@ -1739,7 +1740,7 @@ static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
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if (nr_pages > CHARGE_BATCH)
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return ret;
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- local_irq_save(flags);
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+ local_lock_irqsave(memcg_stock_ll, flags);
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stock = this_cpu_ptr(&memcg_stock);
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if (memcg == stock->cached && stock->nr_pages >= nr_pages) {
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@@ -1747,7 +1748,7 @@ static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
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ret = true;
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}
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- local_irq_restore(flags);
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+ local_unlock_irqrestore(memcg_stock_ll, flags);
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return ret;
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}
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@@ -1774,13 +1775,13 @@ static void drain_local_stock(struct work_struct *dummy)
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struct memcg_stock_pcp *stock;
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unsigned long flags;
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- local_irq_save(flags);
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+ local_lock_irqsave(memcg_stock_ll, flags);
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stock = this_cpu_ptr(&memcg_stock);
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drain_stock(stock);
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clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags);
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- local_irq_restore(flags);
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+ local_unlock_irqrestore(memcg_stock_ll, flags);
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}
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/*
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@@ -1792,7 +1793,7 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
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struct memcg_stock_pcp *stock;
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unsigned long flags;
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- local_irq_save(flags);
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+ local_lock_irqsave(memcg_stock_ll, flags);
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stock = this_cpu_ptr(&memcg_stock);
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if (stock->cached != memcg) { /* reset if necessary */
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@@ -1801,7 +1802,7 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages)
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}
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stock->nr_pages += nr_pages;
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- local_irq_restore(flags);
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+ local_unlock_irqrestore(memcg_stock_ll, flags);
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}
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/*
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--
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2.28.0
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