Hi Pingfan, Thanks for the effort, On 03/01/19 at 11:19am, Pingfan Liu wrote: > On Fri, Mar 1, 2019 at 11:04 AM Pingfan Liu <kernelfans@xxxxxxxxx> wrote: > > > > Hi Borislav, > > > > Do you think the following patch is good at present? > > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c > > index 81f9d23..9213073 100644 > > --- a/arch/x86/kernel/setup.c > > +++ b/arch/x86/kernel/setup.c > > @@ -460,7 +460,7 @@ static void __init > > memblock_x86_reserve_range_setup_data(void) > > # define CRASH_ADDR_LOW_MAX (512 << 20) > > # define CRASH_ADDR_HIGH_MAX (512 << 20) > > #else > > -# define CRASH_ADDR_LOW_MAX (896UL << 20) > > +# define CRASH_ADDR_LOW_MAX (1 << 32) > > # define CRASH_ADDR_HIGH_MAX MAXMEM > > #endif > > > Or patch lools like: > diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c > index 3d872a5..ed0def5 100644 > --- a/arch/x86/kernel/setup.c > +++ b/arch/x86/kernel/setup.c > @@ -459,7 +459,7 @@ static void __init > memblock_x86_reserve_range_setup_data(void) > # define CRASH_ADDR_LOW_MAX (512 << 20) > # define CRASH_ADDR_HIGH_MAX (512 << 20) > #else > -# define CRASH_ADDR_LOW_MAX (896UL << 20) > +# define CRASH_ADDR_LOW_MAX (1 << 32) > # define CRASH_ADDR_HIGH_MAX MAXMEM > #endif > > @@ -551,6 +551,15 @@ static void __init reserve_crashkernel(void) > high ? CRASH_ADDR_HIGH_MAX > : CRASH_ADDR_LOW_MAX, > crash_size, CRASH_ALIGN); > +#ifdef CONFIG_X86_64 > + /* > + * crashkernel=X reserve below 4G fails? Try MAXMEM > + */ > + if (!high && !crash_base) > + crash_base = memblock_find_in_range(CRASH_ALIGN, > + CRASH_ADDR_HIGH_MAX, > + crash_size, CRASH_ALIGN); > +#endif > > which tries 0-4G, the fall back to 4G above This way looks good to me, I will do some testing with old kexec-tools, Once testing done I can take up this again and repost later with some documentation update. Also will split to 2 patches one to drop the old limitation, another for the fallback. Thanks Dave _______________________________________________ kexec mailing list kexec@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/kexec
