Re: [[PATCH]] mips: Fix switch to NO_BOOTMEM for SGI-IP27/loongons3 NUMA

[Mike Rapoport <rppt@linux.ibm.com>]

On Fri, Nov 09, 2018 at 10:54:26AM +0800, 陈华才 wrote:
> Hi,
> 
> It seems the patch below can solve many problems after switched to NO_BOOTMEM, because the memory allocation behavior is more similar as before.

Yes, this should work.
Still, simplifying the max_low_pfn evaluation has it's value regardless.
 
> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index 070234b..7a449d9 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c
> @@ -839,6 +839,7 @@ static void __init arch_mem_init(char **cmdline_p)
> 
>         /* call board setup routine */
>         plat_mem_setup();
> +       memblock_set_bottom_up(true);
> 
>         /*
>          * Make sure all kernel memory is in the maps.  The "UP" and
> diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
> index 0f852e1..15e103c 100644
> --- a/arch/mips/kernel/traps.c
> +++ b/arch/mips/kernel/traps.c
> @@ -2260,10 +2260,8 @@ void __init trap_init(void)
>                 unsigned long size = 0x200 + VECTORSPACING*64;
>                 phys_addr_t ebase_pa;
> 
> -               memblock_set_bottom_up(true);
>                 ebase = (unsigned long)
>                         memblock_alloc_from(size, 1 << fls(size), 0);
> -               memblock_set_bottom_up(false);
> 
>                 /*
>                  * Try to ensure ebase resides in KSeg0 if possible.
> @@ -2307,6 +2305,7 @@ void __init trap_init(void)
>         if (board_ebase_setup)
>                 board_ebase_setup();
>         per_cpu_trap_init(true);
> +       memblock_set_bottom_up(false);
> 
>         /*
>          * Copy the generic exception handlers to their final destination.
> 
>  
> ------------------ Original ------------------
> From:  "Mike Rapoport"<rppt@linux.ibm.com>;
> Date:  Fri, Nov 9, 2018 02:01 AM
> To:  "Thomas Bogendoerfer"<tbogendoerfer@suse.de>;
> Cc:  "Ralf Baechle"<ralf@linux-mips.org>; "Paul Burton"<paul.burton@mips.com>; "James Hogan"<jhogan@kernel.org>; "Huacai Chen"<chenhc@lemote.com>; "linux-mips"<linux-mips@linux-mips.org>; "linux-kernel"<linux-kernel@vger.kernel.org>; "rppt"<rppt@linux.vnet.ibm.com>;
> Subject:  Re: [[PATCH]] mips: Fix switch to NO_BOOTMEM for SGI-IP27/loongons3 NUMA
>  
> 
> 
> On November 8, 2018 6:52:17 PM GMT+02:00, Thomas Bogendoerfer <tbogendoerfer@suse.de> wrote:
> >On Thu, 8 Nov 2018 18:18:23 +0200
> >Mike Rapoport <rppt@linux.ibm.com> wrote:
> >
> >> On Thu, Nov 08, 2018 at 03:44:28PM +0100, Thomas Bogendoerfer wrote:
> >> > Commit bcec54bf3118 ("mips: switch to NO_BOOTMEM") broke SGI-IP27
> >> > and NUMA enabled loongson3 by doing memblock_set_current_limit()
> >> > before max_low_pfn has been evaluated. Both platforms need to do
> >the
> >> > memblock_set_current_limit() in platform specific code. For
> >> > consistency the call to memblock_set_current_limit() is moved
> >> > to the common bootmem_init(), where max_low_pfn is calculated
> >> > for non NUMA enabled platforms.
> >> [..]
> >> 
> >> As for SGI-IP27, the initialization of max_low_pfn as late as in
> >> paging_init() seems to be broken because it's value is used in
> >> arch_mem_init() and in finalize_initrd() anyway.
> >
> >well, the patch is tested on real hardware and the first caller of
> >a memblock_alloc* function is in a function called by
> >free_area_init_nodes().
>  
> Then, apparently, I've missed something else.
> The Onyx2 I worked on is dead for a couple of years now ;-)
> 
> >> AFAIU, both platforms set max_low_pfn to last available pfn, so it
> >seems we
> >> can simply do
> >> 
> >> max_low_pfn = PFN_PHYS(memblock_end_of_DRAM())
> >>
> 
> Should have been PHYS_PFN, sorry.
> 
> >> in the prom_meminit() function for both platforms and drop the loop
> >> evaluating max_low_pfn in paging_init().
> >
> >sounds like a better plan. I'll prepare a new patch.
> >
> >Thomas.
> 
> -- 
> Sent from my Android device with K-9 Mail. Please excuse my brevity.

-- 
Sincerely yours,
Mike.