On Thu, Sep 3, 2015 at 11:35 PM, Sergey Senozhatsky <sergey.senozhatsky.work@xxxxxxxxx> wrote: > > Out of curiosity, I did some quite simple-minded > "slab_nomerge = 0" vs. "slab_nomerge = 1" tests today on my old > x86_64 box (4gigs of RAM, ext4, 4.2.0-next-20150903): So out of interest, was this slab or slub? Also, how repeatable is this? The memory usage between two boots tends to be rather fragile - some of the bigger slab users are dentries and inodes, and various filesystem scanning events will end up skewing things a _lot_. But if it turns out that the numbers are pretty stable, and sharing really doesn't save memory, then that is certainly a big failure. I think Christoph did much of his work for bigger machines where one of the SLAB issues was the NUMA overhead, and who knows - maybe it worked well for the load and machine in question, but not necessarily elsewhere. Interesting. Linus -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel