[PATCH] RISC-V: enable sparsemem by default for defconfig

[Palmer Dabbelt]

On Fri, 21 Oct 2022 17:00:30 +0100, Conor Dooley wrote:
> From: Conor Dooley <conor.dooley at microchip.com>
> 
> on an arch level, RISC-V defaults to FLATMEM. On PolarFire SoC, the
> memory layout is almost always sparse, with a maximum of 1 GiB at
> 0x8000_0000 & a possible 16 GiB range at 0x10_0000_0000. The Icicle kit,
> for example, has 2 GiB of DDR - so there's a big hole in the memory map
> between the two gigs. Prior to v6.1-rc1, boot times from defconfig
> builds were pretty bad on Icicle but enabling sparsemem would fix those
> issues. As of v6.1-rc1, the Icicle kit no longer boots from defconfig
> builds with the in-kernel devicetree. A change to the memory map
> resulted in a futher "sparse-ification", producing a splat on boot:
> 
> [...]

Applied, thanks!

[1/1] RISC-V: enable sparsemem by default for defconfig
      https://git.kernel.org/palmer/c/41555cc9e2e9

I put this one on for-next under the argument it's not actually fixing a
regression: if flatmem is now broken then that's a regression, but just turning
it off isn't really the fix (even if it's still a reasonable thing to do).

Maybe that's kind of pedantic, but it's late in the cycle.

Best regards,
-- 
Palmer Dabbelt <palmer at rivosinc.com>