Re: [PATCH] locking/qrwlock: fix write unlock issue in big endian

[Will Deacon]

On Thu, Jun 02, 2016 at 06:09:08PM +0800, Pan Xinhui wrote:
> strcut __qrwlock has different layout in big endian machine. we need set
> the __qrwlock->wmode to NULL, and the address is not &lock->cnts in big
> endian machine.
> 
> Do as what read unlock does. we are lucky that the __qrwlock->wmode's
> val is _QW_LOCKED.

Doesn't this have wider implications for the qrwlocks, for example:

  while ((cnts & _QW_WMASK) == _QW_LOCKED) { ... }

would actually end up looking at the wrong field of the lock?

Shouldn't we just remove the #ifdef __LITTLE_ENDIAN stuff from __qrwlock,
given that all the struct members are u8?

Will