On Tue, 31 Oct 2023, Chengming Zhou wrote:
The current scheme (which this series implemented) is: - node partial slabs: PG_Workingset (set or clear with per-node list_lock protection) - cpu partial slabs: !PG_Workingset
And then the frozen flag needs to be set. Otherwise slab_free() would conclude it is on a partial list?
- cpu slabs: !PG_Workingset && frozen (set or clear using cmpxchg together with freelist)
- full slabs: !PG_Workingset
And frozen is clear? Otherwise it is the same as a cpu partial slab.
As Vlastimil noted, it's possible to drop "frozen" bit for cpu slabs, but we keep it for performance, since we don't need to grab node list_lock to check whether PG_Workingset is set or not if the "frozen" bit is set. Thanks!
