On 4/28/19 7:12 PM, Waiman Long wrote: > On 4/28/19 6:46 PM, Linus Torvalds wrote: >> This doesn't seem to be the full diff - looking at that patch 1 you >> seem to have taken my suggested list_cut_before() change too. >> >> I'm not against it (it does seem to be simpler and better), I just >> hope you double-checked it, since I kind of hand-waved it. >> >> Linus > I implemented your suggestion in patch 1 as it will produce simpler and > faster code. However, one of the changes in my patchset is to wake up > all the readers in the wait list. This means I have to jump over the > writers and wake up the readers behind them as well. See patch 11 for > details. As a result, I have to revert back to use list_add_tail() and > list_for_each_entry_safe() for the first pass. That is why the diff for > the whole patchset is just the below change. It is done on purpose, not > an omission.
That is also the reason why it was implemented this way in my v6 patchset. I implemented the fix on top of the rwsem patchset first and then move it backward to the beginning of the patchset for easier backport. Cheers, Longman