Looking at a live Android device under load, slab (according to /proc/meminfo) + kernel stack take 8-10% available RAM (~350MB). Kasan's overhead of 2x - 3x on top of it is not insignificant. On Fri, Jun 29, 2018 at 7:41 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Fri, 29 Jun 2018 14:45:08 +0200 Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote: > >> >> What kind of memory consumption testing would you like to see? >> > >> > Well, 100kb or so is a teeny amount on virtually any machine. I'm >> > assuming the savings are (much) more significant once the machine gets >> > loaded up and doing work? >> >> So with clean kernel after boot we get 40 kb memory usage. With KASAN >> it is ~120 kb, which is 200% overhead. With KHWASAN it's 50 kb, which >> is 25% overhead. This should approximately scale to any amounts of >> used slab memory. For example with 100 mb memory usage we would get >> +200 mb for KASAN and +25 mb with KHWASAN. (And KASAN also requires >> quarantine for better use-after-free detection). I can explicitly >> mention the overhead in %s in the changelog. >> >> If you think it makes sense, I can also make separate measurements >> with some workload. What kind of workload should I use? > > Whatever workload people were running when they encountered problems > with KASAN memory consumption ;) > > I dunno, something simple. `find / > /dev/null'? > -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
