On Tue, Feb 11, 2020 at 05:03:02PM -0800, Linus Torvalds wrote: > On Tue, Feb 11, 2020 at 4:47 PM Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > What's the situation with highmem on ARM? > > Afaik it's exactly the same as highmem on x86 - only 32-bit ARM ever > needed it, and I was ranting at some people for repeating all the > mistakes Intel did. > > But arm64 doesn't need it, and while 32-bit arm is obviosuly still > selling, I think that in many ways the switch-over to 64-bit has been > quicker on ARM than it was on x86. Partly because it happened later > (so all the 64-bit teething pains were dealt with), but largely > because everybody ended up actively discouraging 32-bit on the Android > side. > > There were a couple of unfortunate early 32-bit arm server attempts, > but they were - predictably - complete garbage and nobody bought them. > They don't exist any more. > > So at least my gut feel is that the arm people don't have any big > reason to push for maintaining HIGHMEM support either. > > But I'm adding a couple of arm people and the arm list just in case > they have some input. > > [ Obvious background for newly added people: we're talking about > making CONFIG_HIGHMEM a deprecated feature and saying that if you want > to run with lots of memory on a 32-bit kernel, you're doing legacy > stuff and can use a legacy kernel ] Well, the recent 32-bit ARM systems generally have more than 1G of memory, so make use of highmem as a rule. You're probably talking about crippling support for any 32-bit ARM system produced in the last 8 to 10 years. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up According to speedtest.net: 11.9Mbps down 500kbps up
