diff options
| author | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2017-11-22 07:31:19 -0500 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2017-12-01 11:20:36 -0500 |
| commit | c17e74e6b81b2f4a969a66efc7733e54d1fe8a14 (patch) | |
| tree | 239667bb4520d50804198692acd71f63bc953e9b /mm | |
| parent | 4e22accddef27103c4fba20b9613b7bf52129be6 (diff) | |
Revert "memcontrol: Prevent scheduling while atomic in cgroup code"
The commit "memcontrol: Prevent scheduling while atomic in cgroup code"
fixed this issue:
refill_stock()
get_cpu_var()
drain_stock()
res_counter_uncharge()
res_counter_uncharge_until()
spin_lock() <== boom
But commit 3e32cb2e0a12b ("mm: memcontrol: lockless page counters") replaced
the calls to res_counter_uncharge() in drain_stock() to the lockless
function page_counter_uncharge(). There is no more spin lock there and no
more reason to have that local lock.
Cc: stable-rt@vger.kernel.org
Reported-by: Haiyang HY1 Tan <tanhy1@lenovo.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[bigeasy: That upstream commit appeared in v3.19 and the patch in
question in v3.18.7-rt2 and v3.18 seems still to be maintained. So I
guess that v3.18 would need the locallocks that we are about to remove
here. I am not sure if any earlier versions have the patch
backported.
The stable tag here is because Haiyang reported (and debugged) a crash
in 4.4-RT with this patch applied (which has get_cpu_light() instead
the locallocks it gained in v4.9-RT).
https://lkml.kernel.org/r/05AA4EC5C6EC1D48BE2CDCFF3AE0B8A637F78A15@CNMAILEX04.lenovo.com
]
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memcontrol.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 12b94909ba7b..c04403033aec 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1698,7 +1698,6 @@ struct memcg_stock_pcp { #define FLUSHING_CACHED_CHARGE 0 }; static DEFINE_PER_CPU(struct memcg_stock_pcp, memcg_stock); -static DEFINE_LOCAL_IRQ_LOCK(memcg_stock_ll); static DEFINE_MUTEX(percpu_charge_mutex); /** @@ -1721,7 +1720,7 @@ static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) if (nr_pages > CHARGE_BATCH) return ret; - local_lock_irqsave(memcg_stock_ll, flags); + local_irq_save(flags); stock = this_cpu_ptr(&memcg_stock); if (memcg == stock->cached && stock->nr_pages >= nr_pages) { @@ -1729,7 +1728,7 @@ static bool consume_stock(struct mem_cgroup *memcg, unsigned int nr_pages) ret = true; } - local_unlock_irqrestore(memcg_stock_ll, flags); + local_irq_restore(flags); return ret; } @@ -1756,13 +1755,13 @@ static void drain_local_stock(struct work_struct *dummy) struct memcg_stock_pcp *stock; unsigned long flags; - local_lock_irqsave(memcg_stock_ll, flags); + local_irq_save(flags); stock = this_cpu_ptr(&memcg_stock); drain_stock(stock); clear_bit(FLUSHING_CACHED_CHARGE, &stock->flags); - local_unlock_irqrestore(memcg_stock_ll, flags); + local_irq_restore(flags); } /* @@ -1774,7 +1773,7 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) struct memcg_stock_pcp *stock; unsigned long flags; - local_lock_irqsave(memcg_stock_ll, flags); + local_irq_save(flags); stock = this_cpu_ptr(&memcg_stock); if (stock->cached != memcg) { /* reset if necessary */ @@ -1783,7 +1782,7 @@ static void refill_stock(struct mem_cgroup *memcg, unsigned int nr_pages) } stock->nr_pages += nr_pages; - local_unlock_irqrestore(memcg_stock_ll, flags); + local_irq_restore(flags); } /* |