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| author | John David Anglin <dave.anglin@bell.net> | 2020-07-21 07:36:59 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-31 16:44:05 +0200 |
| commit | 518d1af92be83193a44ff279ea10734ffc3b3895 (patch) | |
| tree | 47a9e9c8bf4decdd337b38474df6825226376463 | |
| parent | 77f6d9368c072d89e5ec830152d7e83a1e03df3c (diff) | |
| download | linux-stable-518d1af92be83193a44ff279ea10734ffc3b3895.tar.gz linux-stable-518d1af92be83193a44ff279ea10734ffc3b3895.tar.bz2 linux-stable-518d1af92be83193a44ff279ea10734ffc3b3895.zip | |
parisc: Add atomic64_set_release() define to avoid CPU soft lockups
commit be6577af0cef934ccb036445314072e8cb9217b9 upstream.
Stalls are quite frequent with recent kernels. I enabled
CONFIG_SOFTLOCKUP_DETECTOR and I caught the following stall:
watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [cc1:22803]
CPU: 0 PID: 22803 Comm: cc1 Not tainted 5.6.17+ #3
Hardware name: 9000/800/rp3440
IAOQ[0]: d_alloc_parallel+0x384/0x688
IAOQ[1]: d_alloc_parallel+0x388/0x688
RP(r2): d_alloc_parallel+0x134/0x688
Backtrace:
[<000000004036974c>] __lookup_slow+0xa4/0x200
[<0000000040369fc8>] walk_component+0x288/0x458
[<000000004036a9a0>] path_lookupat+0x88/0x198
[<000000004036e748>] filename_lookup+0xa0/0x168
[<000000004036e95c>] user_path_at_empty+0x64/0x80
[<000000004035d93c>] vfs_statx+0x104/0x158
[<000000004035dfcc>] __do_sys_lstat64+0x44/0x80
[<000000004035e5a0>] sys_lstat64+0x20/0x38
[<0000000040180054>] syscall_exit+0x0/0x14
The code was stuck in this loop in d_alloc_parallel:
4037d414: 0e 00 10 dc ldd 0(r16),ret0
4037d418: c7 fc 5f ed bb,< ret0,1f,4037d414 <d_alloc_parallel+0x384>
4037d41c: 08 00 02 40 nop
This is the inner loop of bit_spin_lock which is called by hlist_bl_unlock in
d_alloc_parallel:
static inline void bit_spin_lock(int bitnum, unsigned long *addr)
{
/*
* Assuming the lock is uncontended, this never enters
* the body of the outer loop. If it is contended, then
* within the inner loop a non-atomic test is used to
* busywait with less bus contention for a good time to
* attempt to acquire the lock bit.
*/
preempt_disable();
#if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK)
while (unlikely(test_and_set_bit_lock(bitnum, addr))) {
preempt_enable();
do {
cpu_relax();
} while (test_bit(bitnum, addr));
preempt_disable();
}
#endif
__acquire(bitlock);
}
After consideration, I realized that we must be losing bit unlocks.
Then, I noticed that we missed defining atomic64_set_release().
Adding this define fixes the stalls in bit operations.
Signed-off-by: Dave Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/parisc/include/asm/atomic.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/parisc/include/asm/atomic.h b/arch/parisc/include/asm/atomic.h index 5394b9c5f914..1616428a5f95 100644 --- a/arch/parisc/include/asm/atomic.h +++ b/arch/parisc/include/asm/atomic.h @@ -255,6 +255,8 @@ atomic64_set(atomic64_t *v, s64 i) _atomic_spin_unlock_irqrestore(v, flags); } +#define atomic64_set_release(v, i) atomic64_set((v), (i)) + static __inline__ s64 atomic64_read(const atomic64_t *v) { |