On Thu, Jan 21, 2021 at 10:08:17AM +0000, Christoph Lameter wrote: > On Wed, 20 Jan 2021, Sudarshan Rajagopalan wrote: > > > But there are other problems in reducing SECTION_SIZE_BIT. Reducing it by too > > much would over populate /sys/devices/system/memory/ and also consume too many > > page->flags bits in the !vmemmap case. Also section size needs to be multiple > > of 128MB to have PMD based vmemmap mapping with CONFIG_ARM64_4K_PAGES. > > There is also the issue of requiring more space in the TLB cache with > smaller page sizes. Or does ARM resolve these into smaller TLB entries > anyways (going on my x86 kwon how here)? Anyways if there are only a few > TLB entries then the effect could > be significant. There is indeed more TLB pressure with smaller page sizes but this patch doesn't change this. -- Catalin
