On 03/28/2019 04:47 PM, Linus Torvalds wrote: > On Thu, Mar 28, 2019 at 11:12 AM Waiman Long <[email protected]> wrote: >> With the merging of owner into count for x86-64, there is only 16 bits >> left for reader count. It is theoretically possible for an application to >> cause more than 64k readers to acquire a rwsem leading to count overflow. > Ahh, and here's the thing that makes 16 bits work for readers. > > I think this at a minimum needs to be made very clear in the patch > that actually lowered the reader count bits, but preferably this just > needs to be done *before* that patch, so that you don't have a point > in history where rwlocks are simply not reliable. > > Linus
Thanks for the suggestion. I will move this patch up in the next version. Cheers, Longman
