On Tue, 26 May 2015, Linus Torvalds wrote: > On Tue, May 26, 2015 at 11:42 AM, Davidlohr Bueso <d...@stgolabs.net> wrote: > > > > Instead of dropping percpu-rwsem, I was thinking we could instead look > > for opportunities to convert new users, for instance shinkers, where the > > write lock is also taken just for register and unregister purposes, > > similar to uprobes. > > So if there really are useful use cases for this, I don't object to > the patch. It seems to just improve on a currently very low-usage > locking primitive. > > And it's not like I conceptually mind the notion of a percpu rwsem, I > just hate seeing specialty locking that isn't really worth it. > > Because as it is, with the current single use, I don't think it's even > worth improving on. > > I _would_ ask that people who are looking at this also look at our > "lglock" thing. It's pretty much *exactly* the same thing, except for > spinlocks, and that one too has exactly two users (the documentation > states that the only user is stop_machine, but in fact file locking > does too). > not sure where this would be missing: Documentation/locking/lglock.txt "Users: currently only the VFS and stop_machine related code"
I atleast did not find any other users as of 3.18 and in 4.0-rc5 this still seems valid. thx! hofrat -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
