[CRIU] [PATCH] lock: print a message if a futex is locked for more than 120 second

[Andrey Vagin]

2015-11-12 21:24 GMT+03:00 Pavel Emelyanov <xemul at parallels.com>:
> On 11/12/2015 07:09 PM, Andrey Vagin wrote:
>> From: Andrew Vagin <avagin at virtuozzo.com>
>>
>> Signed-off-by: Andrew Vagin <avagin at virtuozzo.com>
>> ---
>>  include/lock.h | 19 ++++++++++---------
>>  1 file changed, 10 insertions(+), 9 deletions(-)
>>
>> diff --git a/include/lock.h b/include/lock.h
>> index 89d71b1..392318e 100644
>> --- a/include/lock.h
>> +++ b/include/lock.h
>> @@ -39,12 +39,17 @@ static inline void futex_set(futex_t *f, u32 v)
>>               u32 tmp;                                        \
>>                                                               \
>>               while (1) {                                     \
>> +                     struct timespec to = {.tv_sec = 120};   \
>>                       tmp = (u32)atomic_read(&(__f)->raw);    \
>>                       if ((tmp & FUTEX_ABORT_FLAG) ||         \
>>                           (tmp __cond (__v)))                 \
>>                               break;                          \
>>                       ret = sys_futex((u32 *)&(__f)->raw.counter, FUTEX_WAIT,\
>> -                                     tmp, NULL, NULL, 0);    \
>> +                                     tmp, &to, NULL, 0);     \
>> +                     if (ret == -ETIMEDOUT) {                \
>> +                             pr_warn("blocked for more than 120 seconds\n"); \
>
> I guess it's not extremely informative. Can we add __file__ & __line__ from the
> calling macros here?

pr_warn prints these information and I convert inline functions into
macroses to get proper __file__ and __line__ here

>
>> +                             continue;                       \
>> +                     }                                       \
>>                       BUG_ON(ret < 0 && ret != -EWOULDBLOCK); \
>>               }                                               \
>>       } while (0)
>> @@ -84,20 +89,16 @@ static inline void futex_inc(futex_t *f) { atomic_inc(&f->raw); }
>>  static inline void futex_dec(futex_t *f) { atomic_dec(&f->raw); }
>>
>>  /* Wait until futex @f value become @v */
>> -static inline void futex_wait_until(futex_t *f, u32 v)
>> -{ futex_wait_if_cond(f, v, ==); }
>> +#define futex_wait_until(f, v) futex_wait_if_cond(f, v, ==)
>>
>>  /* Wait while futex @f value is greater than @v */
>> -static inline void futex_wait_while_gt(futex_t *f, u32 v)
>> -{ futex_wait_if_cond(f, v, <=); }
>> +#define futex_wait_while_gt(f, v) futex_wait_if_cond(f, v, <=)
>>
>>  /* Wait while futex @f value is less than @v */
>> -static inline void futex_wait_while_lt(futex_t *f, u32 v)
>> -{ futex_wait_if_cond(f, v, >=); }
>> +#define futex_wait_while_lt(f, v) futex_wait_if_cond(f, v, >=)
>>
>>  /* Wait while futex @f value is equal to @v */
>> -static inline void futex_wait_while_eq(futex_t *f, u32 v)
>> -{ futex_wait_if_cond(f, v, !=); }
>> +#define futex_wait_while_eq(f, v) futex_wait_if_cond(f, v, !=)
>>
>>  /* Wait while futex @f value is @v */
>>  static inline void futex_wait_while(futex_t *f, u32 v)
>>
>