On 12/16/24 16:41, Uladzislau Rezki wrote: > On Mon, Dec 16, 2024 at 03:20:44PM +0100, Vlastimil Babka wrote: >> On 12/16/24 12:03, Uladzislau Rezki wrote: >> > On Sun, Dec 15, 2024 at 06:30:02PM +0100, Vlastimil Babka wrote: >> >> On 12/12/24 19:02, Uladzislau Rezki (Sony) wrote: >> >> > Hello! >> >> > >> >> > This is v2. It is based on the Linux 6.13-rc2. The first version is >> >> > here: >> >> > >> >> > https://lore.kernel.org/linux-mm/20241210164035.3391747-4-urezki@xxxxxxxxx/T/ >> >> > >> >> > The difference between v1 and v2 is that, the preparation process is >> >> > done in original place instead and after that there is one final move. >> >> >> >> Looks good, will include in slab/for-next >> >> >> >> I think patch 5 should add more explanation to the commit message - the >> >> subthread started by Christoph could provide content :) Can you summarize so >> >> I can amend the commit log? >> >> >> > I will :) >> > >> >> Also how about a followup patch moving the rcu-tiny implementation of >> >> kvfree_call_rcu()? >> >> >> > As, Paul already noted, it would make sense. Or just remove a tiny >> > implementation. >> >> AFAICS tiny rcu is for !SMP systems. Do they benefit from the "full" >> implementation with all the batching etc or would that be unnecessary overhead? >> > Yes, it is for a really small systems with low amount of memory. I see > only one overhead it is about driving objects in pages. For a small > system it can be critical because we allocate. > > From the other hand, for a tiny variant we can modify the normal variant > by bypassing batching logic, thus do not consume memory(for Tiny case) > i.e. merge it to a normal kvfree_rcu() path. Maybe we could change it to use CONFIG_SLUB_TINY as that has similar use case (less memory usage on low memory system, tradeoff for worse performance). > After that we do not depend on CONFIG_RCU_TINY option. Probably we need > also to perform some adaptation of regular kvfree_rcu() for a single CPU > system. > > -- > Uladzislau Rezki