Re: [RFC 1/2] rwsem: introduce upgrade_read interface

[lizhe.67@xxxxxxxxxxxxx]

On Wed, 16 Oct 2024 12:49:44 +0100, willy@xxxxxxxxxxxxx wrote:

>On Wed, Oct 16, 2024 at 12:35:59PM +0800, lizhe.67@xxxxxxxxxxxxx wrote:
>> +++ b/include/linux/rwsem.h
>> @@ -249,6 +249,7 @@ DEFINE_GUARD_COND(rwsem_write, _try, down_write_trylock(_T))
>>   * downgrade write lock to read lock
>>   */
>>  extern void downgrade_write(struct rw_semaphore *sem);
>> +extern int upgrade_read(struct rw_semaphore *sem);
>
>This needs __must_check, and I think this should be a bool, not an errno
>return.

I can't agree more. I will fix it in v2.

Thanks!