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

[陈华才 <chenhc@lemote.com>]

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.

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.

-- 
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