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
> For documentation, I will send another patch to improve the description.
>
> Thanks,
> Pingfan
>
> On Mon, Feb 25, 2019 at 7:30 PM Borislav Petkov <bp@xxxxxxxxx> wrote:
> >
> > On Mon, Feb 25, 2019 at 07:12:16PM +0800, Dave Young wrote:
> > > If we move to high as default, it will allocate 160M high + 256M low. It
> >
> > We won't move to high by default - we will *fall* back to high if the
> > default allocation fails.
> >
> > > To make the process less fragile maybe we can remove the 896M limitation
> > > and only try <4G then go to high.
> >
> > Sure, the more robust for the user, the better.
> >
> > --
> > Regards/Gruss,
> > Boris.
> >
> > Good mailing practices for 400: avoid top-posting and trim the reply.
_______________________________________________
kexec mailing list
kexec@xxxxxxxxxxxxxxxxxxx
http://lists.infradead.org/mailman/listinfo/kexec
