On Wed, 2012-10-17 at 11:45 -0700, Tim Bird wrote: > 8G is a small web server? The RAM budget for Linux on one of > Sony's cameras was 10M. We're not merely not in the same ballpark - > you're in a ballpark and I'm trimming bonsai trees... :-) > Even laptops in 2012 have +4GB of ram. (Maybe not Sony laptops, I have to double check ?) Yes, servers do have more ram than laptops. (Maybe not Sony servers, I have to double check ?) > > # grep Slab /proc/meminfo > > Slab: 351592 kB > > > > # egrep "kmalloc-32|kmalloc-16|kmalloc-8" /proc/slabinfo > > kmalloc-32 11332 12544 32 128 1 : tunables 0 0 0 : slabdata 98 98 0 > > kmalloc-16 5888 5888 16 256 1 : tunables 0 0 0 : slabdata 23 23 0 > > kmalloc-8 76563 82432 8 512 1 : tunables 0 0 0 : slabdata 161 161 0 > > > > Really, some waste on these small objects is pure noise on SMP hosts. > In this example, it appears that if all kmalloc-8's were pushed into 32-byte slabs, > we'd lose about 1.8 meg due to pure slab overhead. This would not be noise > on my system. I said : <quote> I would remove small kmalloc-XX caches, as sharing a cache line is sometime dangerous for performance, because of false sharing. They make sense only for very small hosts </quote> I think your 10M cameras are very tiny hosts. Using SLUB on them might not be the best choice. First time I ran linux, years ago, it was on 486SX machines with 8M of memory (or maybe less, I dont remember exactly). But I no longer use this class of machines with recent kernels. # size vmlinux text data bss dec hex filename 10290631 1278976 1896448 13466055 cd79c7 vmlinux -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>