On Thu, Feb 01, 2024 at 03:49:06PM +0000, Chengming Zhou wrote: > Since we don't need to leave zswap entry on the zswap tree anymore, > we should remove it from tree once we find it from the tree. > > Then after using it, we can directly free it, no concurrent path > can find it from tree. Only the shrinker can see it from lru list, > which will also double check under tree lock, so no race problem. > > So we don't need refcount in zswap entry anymore and don't need to > take the spinlock for the second time to invalidate it. > > The side effect is that zswap_entry_free() maybe not happen in tree > spinlock, but it's ok since nothing need to be protected by the lock. > > Signed-off-by: Chengming Zhou <zhouchengming@xxxxxxxxxxxxx> This looks like a great simplification, and a good motivation to only support exclusive loads. Everything is more straightforward because every tree lookup implies a removal and exclusive ownership. Let's see if removing support for non-exclusive loads is agreeable first though :)
