Re: [PATCHv3 2/2] arm: Get rid of meminfo

Laura Abbott
2014-02-13T02:17:55Z

On 2/12/2014 7:09 AM, Grygorii Strashko wrote:
> Hi Laura,
>
> On 02/11/2014 11:14 PM, Laura Abbott wrote:
>> memblock is now fully integrated into the kernel and is the prefered
>> method for tracking memory. Rather than reinvent the wheel with
>> meminfo, migrate to using memblock directly instead of meminfo as
>> an intermediate.
>>
>> Acked-by: Jason Cooper <jason@lakedaemon.net>
>> Acked-by: Catalin Marinas <catalin.marinas@arm.com>
>> Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
>> Tested-by: Leif Lindholm <leif.lindholm@linaro.org>
>> Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
>> ---
>> arch/arm/include/asm/mach/arch.h | 4 +-
>> arch/arm/include/asm/memblock.h | 3 +-
>> arch/arm/include/asm/setup.h | 23 ------
>> arch/arm/kernel/atags_parse.c | 5 +-
>> arch/arm/kernel/devtree.c | 5 --
>> arch/arm/kernel/setup.c | 30 ++------
>> arch/arm/mach-clps711x/board-clep7312.c | 7 +-
>> arch/arm/mach-clps711x/board-edb7211.c | 10 +--
>> arch/arm/mach-clps711x/board-p720t.c | 2 +-
>> arch/arm/mach-footbridge/cats-hw.c | 2 +-
>> arch/arm/mach-footbridge/netwinder-hw.c | 2 +-
>> arch/arm/mach-msm/board-halibut.c | 6 --
>> arch/arm/mach-msm/board-mahimahi.c | 13 +---
>> arch/arm/mach-msm/board-msm7x30.c | 3 +-
>> arch/arm/mach-msm/board-sapphire.c | 13 ++--
>> arch/arm/mach-msm/board-trout.c | 8 +--
>> arch/arm/mach-orion5x/common.c | 3 +-
>> arch/arm/mach-orion5x/common.h | 3 +-
>> arch/arm/mach-pxa/cm-x300.c | 3 +-
>> arch/arm/mach-pxa/corgi.c | 10 +--
>> arch/arm/mach-pxa/eseries.c | 9 +--
>> arch/arm/mach-pxa/poodle.c | 8 +--
>> arch/arm/mach-pxa/spitz.c | 8 +--
>> arch/arm/mach-pxa/tosa.c | 8 +--
>> arch/arm/mach-realview/core.c | 11 +--
>> arch/arm/mach-realview/core.h | 3 +-
>> arch/arm/mach-realview/realview_pb1176.c | 8 +--
>> arch/arm/mach-realview/realview_pbx.c | 17 ++---
>> arch/arm/mach-s3c24xx/mach-smdk2413.c | 8 +--
>> arch/arm/mach-s3c24xx/mach-vstms.c | 8 +--
>> arch/arm/mach-sa1100/assabet.c | 2 +-
>> arch/arm/mm/init.c | 67 +++++++-----------
>> arch/arm/mm/mmu.c | 115 +++++++++---------------------
>
> The arch/arm/mm/nommu.c has to be updated too :)
>

Sure does.

> [...]
>
> I've tested your change on keystone (with some additional printouts in sanity_check_meminfo())
> and got following results:
>
> - without your change + HIGHMEM=ON
> [ 0.000000] ==== memblock_limit0x00000000af800000, arm_lowmem_limit0x00000000af800000 high_memoryef800000 vmalloc_limit0x00000000af800000
>
> - without your change + HIGHMEM=OFF
> [ 0.000000] Truncating RAM at 80000000-bfffffff to -af7fffff (vmalloc region overlap).
> [ 0.000000] ==== memblock_limit0x00000000af800000, arm_lowmem_limit0x00000000af800000 high_memoryef800000 vmalloc_limit0x00000000af800000
>
> - with your change + HIGHMEM=ON
> [ 0.000000] ==== memblock_limit0x00000000af800000, arm_lowmem_limit0x00000000af800000 high_memoryef800000 vmalloc_limit0x00000000af800000
>
> - with your change + HIGHMEM=OFF
> [ 0.000000] Truncating RAM at 0x0000000080000000-0x00000000c0000000 to -0x0000000010800000
> ^printout changed
> [ 0.000000] ==== memblock_limit0x00000000af800000, arm_lowmem_limit0x00000000af800000 high_memoryef800000 vmalloc_limit0x00000000af800000
>
> Keystone mem defined as: from@0x80000000 size@0x40000000 (LPAE=OFF)
>
> As result, i have few comments regarding sanity_check_meminfo() changes as I think there are
> some issues &side effects changes at least in printouts - see below.
>
>> memblock_reserve(__pa(_sdata), _end - _sdata);
>> @@ -413,54 +397,53 @@ free_memmap(unsigned long start_pfn, unsigned long end_pfn)
>> /*
>> * The mem_map array can get very big. Free the unused area of the memory map.
>> */
>> -static void __init free_unused_memmap(struct meminfo *mi)
>> +static void __init free_unused_memmap(void)
>> {
>> - unsigned long bank_start, prev_bank_end = 0;
>> - unsigned int i;
>> + unsigned long start, prev_end = 0;
>> + struct memblock_region *reg;
>>
>> /*
>> * This relies on each bank being in address order.
>> * The banks are sorted previously in bootmem_init().
>> */
>> - for_each_bank(i, mi) {
>> - struct membank *bank = &mi->bank[i];
>> -
>> - bank_start = bank_pfn_start(bank);
>> + for_each_memblock(memory, reg) {
>> + start = __phys_to_pfn(reg->base);
>
> memblock_region_memory_base_pfn() can be used here.
>

Okay

>>
>> #ifdef CONFIG_SPARSEMEM
>> /*
>> * Take care not to free memmap entries that don't exist
>> * due to SPARSEMEM sections which aren't present.
>> */
>> - bank_start = min(bank_start,
>> - ALIGN(prev_bank_end, PAGES_PER_SECTION));
>> + start = min(start,
>> + ALIGN(prev_end, PAGES_PER_SECTION));
>> #else
>> /*
>> * Align down here since the VM subsystem insists that the
>> * memmap entries are valid from the bank start aligned to
>> * MAX_ORDER_NR_PAGES.
>> */
>> - bank_start = round_down(bank_start, MAX_ORDER_NR_PAGES);
>> + start = round_down(start, MAX_ORDER_NR_PAGES);
>> #endif
>> /*
>> * If we had a previous bank, and there is a space
>> * between the current bank and the previous, free it.
>> */
>> - if (prev_bank_end && prev_bank_end < bank_start)
>> - free_memmap(prev_bank_end, bank_start);
>> + if (prev_end && prev_end < start)
>> + free_memmap(prev_end, start);
>>
>> /*
>> * Align up here since the VM subsystem insists that the
>> * memmap entries are valid from the bank end aligned to
>> * MAX_ORDER_NR_PAGES.
>> */
>> - prev_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES);
>> + prev_end = ALIGN(start + __phys_to_pfn(reg->size),
>
> I think, start + __phys_to_pfn(reg->size) can be replaced by
> memblock_region_memory_end_pfn().
>

Okay

>> + MAX_ORDER_NR_PAGES);
>> }
>>
>> #ifdef CONFIG_SPARSEMEM
>> - if (!IS_ALIGNED(prev_bank_end, PAGES_PER_SECTION))
>> - free_memmap(prev_bank_end,
>> - ALIGN(prev_bank_end, PAGES_PER_SECTION));
>> + if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
>> + free_memmap(prev_end,
>> + ALIGN(prev_end, PAGES_PER_SECTION));
>> #endif
>> }
>>
>> @@ -536,7 +519,7 @@ void __init mem_init(void)
>> set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
>>
>> /* this will put all unused low memory onto the freelists */
>> - free_unused_memmap(&meminfo);
>> + free_unused_memmap();
>> free_all_bootmem();
>>
>> #ifdef CONFIG_SA1111
>> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
>> index 4f08c13..23433ef 100644
>> --- a/arch/arm/mm/mmu.c
>> +++ b/arch/arm/mm/mmu.c
>> @@ -1046,74 +1046,44 @@ phys_addr_t arm_lowmem_limit __initdata = 0;
>> void __init sanity_check_meminfo(void)
>> {
>> phys_addr_t memblock_limit = 0;
>> - int i, j, highmem = 0;
>> + int highmem = 0;
>> phys_addr_t vmalloc_limit = __pa(vmalloc_min - 1) + 1;
>> + struct memblock_region *reg;
>>
>> - for (i = 0, j = 0; i < meminfo.nr_banks; i++) {
>> - struct membank *bank = &meminfo.bank[j];
>> - phys_addr_t size_limit;
>> -
>> - *bank = meminfo.bank[i];
>> - size_limit = bank->size;
>> + for_each_memblock(memory, reg) {
>> + phys_addr_t block_start = reg->base;
>> + phys_addr_t block_end = reg->base + reg->size;
>> + phys_addr_t size_limit = reg->size;
>>
>> - if (bank->start >= vmalloc_limit)
>> + if (reg->base >= vmalloc_limit)
>> highmem = 1;
>> else
>> - size_limit = vmalloc_limit - bank->start;
>> + size_limit = vmalloc_limit - reg->base;
>>
>> - bank->highmem = highmem;
>>
>> -#ifdef CONFIG_HIGHMEM
>> - /*
>> - * Split those memory banks which are partially overlapping
>> - * the vmalloc area greatly simplifying things later.
>> - */
>> - if (!highmem && bank->size > size_limit) {
>> - if (meminfo.nr_banks >= NR_BANKS) {
>> - printk(KERN_CRIT "NR_BANKS too low, "
>> - "ignoring high memory\n");
>> - } else {
>> - memmove(bank + 1, bank,
>> - (meminfo.nr_banks - i) * sizeof(*bank));
>> - meminfo.nr_banks++;
>> - i++;
>> - bank[1].size -= size_limit;
>> - bank[1].start = vmalloc_limit;
>> - bank[1].highmem = highmem = 1;
>> - j++;
>> + if (!IS_ENABLED(CONFIG_HIGHMEM) || cache_is_vipt_aliasing()) {
>> +
>> + if (highmem) {
>> + pr_notice("Ignoring ram at %pa-%pa (!CONFIG_HIGHMEM)\n",
>> + &block_start, &block_end);
>> + memblock_remove(block_start, block_end);
>
> The wrong size is used here, should be => memblock_remove(block_start, reg->size);
> or => memblock_remove(block_start, size_limit);
>

Yes, you are correct. I'm guessing I meant to do block_end-block_start
and missed the last part.

>> + continue;
>> }
>> - bank->size = size_limit;
>> - }
>> -#else
>> - /*
>> - * Highmem banks not allowed with !CONFIG_HIGHMEM.
>> - */
>> - if (highmem) {
>> - printk(KERN_NOTICE "Ignoring RAM at %.8llx-%.8llx "
>> - "(!CONFIG_HIGHMEM).\n",
>> - (unsigned long long)bank->start,
>> - (unsigned long long)bank->start + bank->size - 1);
>> - continue;
>> - }
>>
>> - /*
>> - * Check whether this memory bank would partially overlap
>> - * the vmalloc area.
>> - */
>> - if (bank->size > size_limit) {
>> - printk(KERN_NOTICE "Truncating RAM at %.8llx-%.8llx "
>> - "to -%.8llx (vmalloc region overlap).\n",
>> - (unsigned long long)bank->start,
>> - (unsigned long long)bank->start + bank->size - 1,
>> - (unsigned long long)bank->start + size_limit - 1);
>> - bank->size = size_limit;
>> + if (reg->size > size_limit) {
>> + phys_addr_t overlap_size = reg->size - size_limit;
>> +
>> + pr_notice("Truncating RAM at %pa-%pa to -%pa",
>> + &block_start, &block_end, &overlap_size);
>
> Pls, change it back to show new RAM limit instead of size.
> pr_notice("Truncating RAM at %pa-%pa to -%pa",
> &block_start, &block_end, &vmalloc_limit);
>
>
>> + memblock_remove(vmalloc_limit, overlap_size);
>> + block_end = vmalloc_limit;
>> + }
>> }
>> -#endif
>> - if (!bank->highmem) {
>> - phys_addr_t bank_end = bank->start + bank->size;
>>
>> - if (bank_end > arm_lowmem_limit)
>> - arm_lowmem_limit = bank_end;
>> + if (!highmem) {
>> + if (block_end > arm_lowmem_limit)
>> + arm_lowmem_limit = reg->base + size_limit;
>> +
>
> if !highmem then size_limit will be calculated as vmalloc_limit - reg->base
> which in turn can be greater than reg->size. So, arm_lowmem_limit can point on
> non existent memory address.
>
> Seems, it should be:
> arm_lowmem_limit = block_end;
>

Yes, I believe so. I will review it.

>>
>> /*
>> * Find the first non-section-aligned page, and point
>> @@ -1129,35 +1099,16 @@ void __init sanity_check_meminfo(void)
>> * occurs before any free memory is mapped.
>> */
>> if (!memblock_limit) {
>> - if (!IS_ALIGNED(bank->start, SECTION_SIZE))
>> - memblock_limit = bank->start;
>> - else if (!IS_ALIGNED(bank_end, SECTION_SIZE))
>> - memblock_limit = bank_end;
> [...]
>
> Thanks for your patience :)
>

Thanks for the review and debugging!

> Regards,
> -grygorii
>

Thanks,
Laura

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