On Sun, Sep 27, 2026 at 01:15:39PM -0400, Mathieu Desnoyers wrote: [...] > > > With this change, the scan on per-CPU slots don't need to expect a > > > wildcard anymore, because none can be produced by readers. Wildcards are > > > only expected within overflow lists. > > > > > > > Ok, I was missing something, but I think it's better to call it out. > > Wildcards can only exist in the overflow lists when the context is not > > preemptible. In other words, there won't be a preempted readers blocking > > the synchronize_hazptr() with a wilcard in the overflow list. > > Exactly ! Wildcard slots only exist during the short time-frame of the > preempt-off read-side code region (few instructions). And with this > patch, this does not even happen very often, because the fast path don't > rely on the wildcards. > > > > > So no more design trade-off question from me :) > > > > Are you sure ? Scrolling down.... >
I do feel with scan thread support and call_hazptr() support, we will need to tweak the design and implementation some more, but right now it does look good to me :) Regards, Boqun [...]
