On 23/09/16 14:51, Alexey Kardashevskiy wrote: > The moderm kernel on powernv platform cannot possibly boot with values > less than 12 as the default DMA window of 2GB requires > (2<<30)/4096 TCEs which is 4MB of contiguous memory, log2(4M) == 22 > so anything less than 12 won't work. > > Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru> > --- > > I am hitting this when switching the system page size from 64K to 4K and > back. When I switch to 64K, zone order is set to 9 by default and > it does not change when I switch to 4K as 9 is still within the limits. > And there are other folks complaining about this too. > --- > arch/powerpc/Kconfig | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 927d2ab..3516f16 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -637,7 +637,7 @@ config FORCE_MAX_ZONEORDER > int "Maximum zone order" > range 8 9 if PPC64 && PPC_64K_PAGES > default "9" if PPC64 && PPC_64K_PAGES > - range 9 13 if PPC64 && !PPC_64K_PAGES > + range 12 13 if PPC64 && !PPC_64K_PAGES > default "13" if PPC64 && !PPC_64K_PAGES > range 9 64 if PPC32 && PPC_16K_PAGES > default "9" if PPC32 && PPC_16K_PAGES >
Aneesh already submitted a patch for this Balbir Singh.
