On 2024/6/6 13:43, Sergey Senozhatsky wrote: > On (24/06/06 12:46), Chengming Zhou wrote: >>>> Agree, I think we should try to improve locking scalability of zsmalloc. >>>> I have some thoughts to share, no code or test data yet: >>>> >>>> 1. First, we can change the pool global lock to per-class lock, which >>>> is more fine-grained. >>> >>> Commit c0547d0b6a4b6 "zsmalloc: consolidate zs_pool's migrate_lock >>> and size_class's locks" [1] claimed no significant difference >>> between class->lock and pool->lock. >> >> Ok, I haven't looked into the history much, that seems preparation of trying >> to introduce reclaim in the zsmalloc? Not sure. But now with the reclaim code >> in zsmalloc has gone, should we change back to the per-class lock? Which is > > Well, the point that commit made was that Nhat (and Johannes?) were > unable to detect any impact of pool->lock on a variety of cases. So > we went on with code simplification. Right, the code is simpler. > >> obviously more fine-grained than the pool lock. Actually, I have just done it, >> will test to get some data later. > > Thanks, we'll need data on this. I'm happy to take the patch, but > jumping back and forth between class->lock and pool->lock merely > "for obvious reasons" is not what I'm extremely excited about. Yeah, agree, we need test data.
