Re: [PATCH 2/2] MIPS: Add fix_range_node after parse "mem=" parameter

[Jinyang He]

On 12/03/2020 05:27 PM, Jiaxun Yang wrote:
> 于 2020年12月3日 GMT+08:00 下午4:57:47, Jinyang He <hejinyang@xxxxxxxxxxx> 写到:
> > This problem may only occur on NUMA platforms. When machine start
> > with the "mem=" parameter on Loongson64, it cannot boot. When parsing the
> > "mem=" parameter, first all the RAM was removed, and then the memory was
> > not added by memblock_add_node(), which caused the newly added memory to
> > be on MAX_NUMNODES. The key to solve this problem is to fix these memory
> > nodes through memblock_set_node() before bootmem_init() or earlier. So
> > it would be better to fix it before check_kernel_sections_mem().
> > The check_kernel_sections_mem() will check whether the current RAM can be
> > used by the kernel. If this fix is added after that, it will do a redundant
> > memblock_add operation. Adding the fixup_region_node() function can also
> > provide a reference for future platforms using NUMA when encountering
> > such problems.
> Hi Jingyang,
>
> Is it possible to do it when parsing cmdline to avoid this kind of fixup?
>
> Thanks.
>
> - Jiaxun

Hi, Jiaxun,

Of course. But "memmap=" could cause same problem , "mem=" could
parse many times. So it better to fix it after these parse opertion 
having done.

Thanks,
Jinyang.

> > Signed-off-by: Jinyang He <hejinyang@xxxxxxxxxxx>
> > ---
> > arch/mips/include/asm/bootinfo.h |  1 +
> > arch/mips/kernel/setup.c         |  6 +++++-
> > arch/mips/loongson64/numa.c      | 11 +++++++++++
> > 3 files changed, 17 insertions(+), 1 deletion(-)
> >
> > diff --git a/arch/mips/include/asm/bootinfo.h b/arch/mips/include/asm/bootinfo.h
> > index aa03b12..ddc17b1 100644
> > --- a/arch/mips/include/asm/bootinfo.h
> > +++ b/arch/mips/include/asm/bootinfo.h
> > @@ -91,6 +91,7 @@ const char *get_system_type(void);
> > extern unsigned long mips_machtype;
> >
> > extern void detect_memory_region(phys_addr_t start, phys_addr_t sz_min,  phys_addr_t sz_max);
> > +extern void fixup_region_node(void);
> >
> > extern void prom_init(void);
> > extern void prom_free_prom_memory(void);
> > diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> > index b3a711e..fe93882 100644
> > --- a/arch/mips/kernel/setup.c
> > +++ b/arch/mips/kernel/setup.c
> > @@ -110,6 +110,8 @@ void __init detect_memory_region(phys_addr_t start, phys_addr_t sz_min, phys_add
> > 	memblock_add(start, size);
> > }
> >
> > +void __weak fixup_region_node(void) {}
> > +
> > /*
> >   * Manage initrd
> >   */
> > @@ -631,8 +633,10 @@ static void __init arch_mem_init(char **cmdline_p)
> >
> > 	parse_early_param();
> >
> > -	if (usermem)
> > +	if (usermem) {
> > 		pr_info("User-defined physical RAM map overwrite\n");
> > +		fixup_region_node();
> > +	}
> >
> > 	check_kernel_sections_mem();
> >
> > diff --git a/arch/mips/loongson64/numa.c b/arch/mips/loongson64/numa.c
> > index c6f0c48..d8661cc 100644
> > --- a/arch/mips/loongson64/numa.c
> > +++ b/arch/mips/loongson64/numa.c
> > @@ -220,6 +220,17 @@ void __init mem_init(void)
> > 	mem_init_print_info(NULL);
> > }
> >
> > +void __init fixup_region_node(void)
> > +{
> > +	phys_addr_t start, end;
> > +	u64 i;
> > +
> > +	for_each_mem_range(i, &start, &end) {
> > +		memblock_set_node(start, end - start,
> > +				  &memblock.memory, pa_to_nid(start));
> > +	}
> > +}
> > +
> > /* All PCI device belongs to logical Node-0 */
> > int pcibus_to_node(struct pci_bus *bus)
> > {