On 12/15/21 07:29, Hyeonggon Yoo wrote: > On Tue, Dec 14, 2021 at 06:24:58PM +0100, Vlastimil Babka wrote: >> On 12/10/21 13:06, Christoph Lameter wrote: >> > On Fri, 10 Dec 2021, Hyeonggon Yoo wrote: >> > >> >> > > (But I still have doubt if we can run linux on machines like that.) >> >> > >> >> > I sent you a series of articles about making Linux run in 1MB. >> >> >> >> After some time playing with the size of kernel, >> >> I was able to run linux in 6.6MiB of RAM. and the SLOB used >> >> around 300KiB of memory. >> > >> > What is the minimal size you need for SLUB? >> > > I don't know why Christoph's mail is not in my mailbox. maybe I deleted it > by mistake or I'm not cc-ed. > > Anyway, I tried to measure this again with SLUB and SLOB. > > SLUB uses few hundreds of bytes than SLOB. > > There isn't much difference in 'Memory required to boot'. > (interestingly SLUB requires less) > > 'Memory required to boot' is measured by reducing memory > until it says 'System is deadlocked on memory'. I don't know > exact reason why they differ. > > Note that the configuration is based on tinyconfig and > I added initramfs support + tty layer (+ uart driver) + procfs support, > + ELF binary support + etc. > > there isn't even block layer, but it's good starting point to see > what happens in small system. > > SLOB: > > Memory required to boot: 6950K > > Slab: 368 kB > > SLUB: > Memory required to boot: 6800K > > Slab: 552 kB > > SLUB with slab merging: > > Slab: 536 kB 168kB different on a system with less than 8MB memory looks rather significant to me to simply delete SLOB, I'm afraid.
