Re: [PATCH v2 10/10] ARM: p2v: reduce p2v alignment requirement to 2 MiB
From: Nicolas Pitre <nico@fluxnic.net>
Date: 2020-09-22 15:14:49
Also in:
linux-efi
On Tue, 22 Sep 2020, Ard Biesheuvel wrote:
By changing the patchable sequences and the patching logic to carry more bits of offset, we can improve this: 11 bits gives us 4 GiB >> 11 == 2 MiB granularity, and so you never waste more than that amount by rounding up the physical start of DRAM to the next multiple of 2 MiB. (Note that 2 MiB granularity guarantees that the linear mapping can be created efficiently, whereas less than 2 MiB may result in the linear mapping needing another level of page tables)
That is IMHO the top argument for limiting it to 2 MiB. It would be worth making this explicit in the commit log. Nicolas _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel