diff options
| author | Zqiang <qiang1.zhang@intel.com> | 2022-06-12 04:02:25 +0200 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-06-22 00:57:04 +0200 |
| commit | 7bf336fb8dac718febb7bf4fe79e1be0c5e4a631 (patch) | |
| tree | fe467e138cf5fe06b9a667a436909dfcdc538d74 /kernel/rcu | |
| parent | rcutorture: Handle failure of memory allocation functions (diff) | |
| download | linux-7bf336fb8dac718febb7bf4fe79e1be0c5e4a631.tar.xz linux-7bf336fb8dac718febb7bf4fe79e1be0c5e4a631.zip | |
refscale: Convert test_lock spinlock to raw_spinlock
In kernels built with CONFIG_PREEMPT_RT=y, spinlocks are replaced by
rt_mutex, which can sleep. This means that acquiring a non-raw spinlock
in a critical section where preemption is disabled can trigger the
following BUG:
BUG: scheduling while atomic: ref_scale_reade/76/0x00000002
Preemption disabled at:
ref_lock_section+0x16/0x80
Call Trace:
<TASK>
dump_stack_lvl+0x5b/0x82
dump_stack+0x10/0x12
__schedule_bug.cold+0x9c/0xad
__schedule+0x839/0xc00
schedule_rtlock+0x22/0x40
rtlock_slowlock_locked+0x460/0x1350
rt_spin_lock+0x61/0xe0
ref_lock_section+0x29/0x80
rcu_scale_one_reader+0x52/0x60
ref_scale_reader+0x28d/0x490
kthread+0x128/0x150
ret_from_fork+0x22/0x30
</TASK>
This commit therefore converts spinlock to raw_spinlock.
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/refscale.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/kernel/rcu/refscale.c b/kernel/rcu/refscale.c index 909644abee67..435c884c02b5 100644 --- a/kernel/rcu/refscale.c +++ b/kernel/rcu/refscale.c @@ -385,7 +385,7 @@ static struct ref_scale_ops rwsem_ops = { }; // Definitions for global spinlock -static DEFINE_SPINLOCK(test_lock); +static DEFINE_RAW_SPINLOCK(test_lock); static void ref_lock_section(const int nloops) { @@ -393,8 +393,8 @@ static void ref_lock_section(const int nloops) preempt_disable(); for (i = nloops; i >= 0; i--) { - spin_lock(&test_lock); - spin_unlock(&test_lock); + raw_spin_lock(&test_lock); + raw_spin_unlock(&test_lock); } preempt_enable(); } @@ -405,9 +405,9 @@ static void ref_lock_delay_section(const int nloops, const int udl, const int nd preempt_disable(); for (i = nloops; i >= 0; i--) { - spin_lock(&test_lock); + raw_spin_lock(&test_lock); un_delay(udl, ndl); - spin_unlock(&test_lock); + raw_spin_unlock(&test_lock); } preempt_enable(); } @@ -427,8 +427,8 @@ static void ref_lock_irq_section(const int nloops) preempt_disable(); for (i = nloops; i >= 0; i--) { - spin_lock_irqsave(&test_lock, flags); - spin_unlock_irqrestore(&test_lock, flags); + raw_spin_lock_irqsave(&test_lock, flags); + raw_spin_unlock_irqrestore(&test_lock, flags); } preempt_enable(); } @@ -440,9 +440,9 @@ static void ref_lock_irq_delay_section(const int nloops, const int udl, const in preempt_disable(); for (i = nloops; i >= 0; i--) { - spin_lock_irqsave(&test_lock, flags); + raw_spin_lock_irqsave(&test_lock, flags); un_delay(udl, ndl); - spin_unlock_irqrestore(&test_lock, flags); + raw_spin_unlock_irqrestore(&test_lock, flags); } preempt_enable(); } |