(CC zsmalloc maintainers) On Sat, 2020-12-19 at 11:59 +0100, Mike Galbraith wrote: > On Sat, 2020-12-19 at 11:46 +0100, Vitaly Wool wrote: > > On Sat, 19 Dec 2020, 11:27 Mike Galbraith, <efault@xxxxxx> wrote: > > > > > The kernel that generated that splat was NOT an RT kernel, it was plain > > > master.today with a PREEMPT config. > > > > > > I see, thanks. I don't think it makes things better for zsmalloc > > though. From what I can see, the offending code is this: > > > > > /* From now on, migration cannot move the object */ > > > pin_tag(handle); > > > > Bit spinlock is taken in pin_tag(). I find the comment above somewhat > > misleading, why is it necessary to take a spinlock to prevent > > migration? I would guess an atomic flag should normally be enough. > > > > zswap is not broken here, it is zsmalloc that needs to be fixed. > > Cool, those damn bit spinlocks going away would be a case of happiness > for RT as well :) > > -Mike
