Re: [PATCH] MIPS: Increase range of CONFIG_FORCE_MAX_ZONEORDER

From: Paul Cercueil
Date: Tue Sep 22 2020 - 13:12:03 EST


Hi Thomas,

Le mar. 22 sept. 2020 à 18:02, Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx> a écrit :
On Thu, Sep 17, 2020 at 03:35:28PM +0200, Paul Cercueil wrote:
There is nothing that prevents us from using lower maximum values.
It's something that we actually want, when using bigger page sizes on
devices with low RAM.

Signed-off-by: Paul Cercueil <paul@xxxxxxxxxxxxxxx>
---
arch/mips/Kconfig | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 632fe8fe68c4..dca2bbdbfc24 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -2251,7 +2251,7 @@ config FORCE_MAX_ZONEORDER
default "13" if MIPS_HUGE_TLB_SUPPORT && PAGE_SIZE_32KB
range 12 64 if MIPS_HUGE_TLB_SUPPORT && PAGE_SIZE_16KB
default "12" if MIPS_HUGE_TLB_SUPPORT && PAGE_SIZE_16KB
- range 11 64
+ range 0 64

Do we need the range at all ? Most other archs don't use a range...

The maximum contiguous block size cannot be lower than a huge page, so that's why the 'range' are here.

Which makes me think that there should probably be a "range 11 64 if MIPS_HUGE_TLB_SUPPORT && PAGE_SIZE_8KB" and the same for 4KB pages.

With a lower value and huge pages enabled in the config, the kernel probably would not boot.

Cheers,
-Paul