Hi, On 23 April 2015 at 23:41, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Thu, 23 Apr 2015 22:26:18 +0000 "Luck, Tony" <tony.luck@xxxxxxxxx> wrote: > >> > Memory fails me. Why do some architectures (arm, arm64, x86_64) want >> > huge_pmd_[un]share() while other architectures (ia64, tile, mips, >> > powerpc, metag, sh, s390) do not? >> >> Potentially laziness/ignorance-of-feature? It looks like this feature started on x86_64 and then spread >> to arm*. > > Yes. In 3212b535f200c85b5a6 Steve Capper (ARM person) hoisted the code > out of x86 into generic, then made arm use it. I tested the pmd sharing code that x86 had and it worked well on ARM too so I bundled it in when I generalised some of the huge page code. I didn't know enough about the other architectures to enable it for them, so played things safe by leaving it disabled for them. Looking at this patch, I could have done that more cleanly though. > > We're not (I'm not) very good about letting arch people know about such > things. I wonder how to fix that; does linux-arch work? > linux-arch is working for me, maybe a good idea to CC in some arch maintainers too. Cheers, -- Steve -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>