On 2025-04-04 at 09:59:49 -0700, Dave Hansen wrote: >On 4/4/25 06:14, Maciej Wieczor-Retman wrote: >> Adjust x86 minimal SLAB alignment to match KASAN granularity size. In >> tag-based mode the size changes to 16 bytes so the value needs to be 16. > >I feel like we need a _bit_ of a discussion of the impact here. We are, >after all, trying to get this feature into shape so that it can be used >more widely outside of just debugging environments. > >What's the impact of this in a production environment? I tried booting a fedora 41 on a Sierra Forest system with KASAN disabled (disabled only the reports so the 8 byte alignment doesn't cause a wall of debug information). Did so for both 8 byte alignment (default) and 16 byte alignment (added by the series). The differences looked mostly like noise, sometimes the higher alignment would use up a little bit less memory, sometimes a little bit more. I looked at all values in "cat /proc/meminfo". Is there some slab/slub benchmark for the kernel that would make sense to checkout here? -- Kind regards Maciej Wieczór-Retman
