Re: [PATCHv2 3/7] mm/memblock: introduce allocation boundary for tracing purpose

[Mike Rapoport]

Hi Pingfan,

On Fri, Jan 11, 2019 at 01:12:53PM +0800, Pingfan Liu wrote:
> During boot time, there is requirement to tell whether a series of func
> call will consume memory or not. For some reason, a temporary memory
> resource can be loan to those func through memblock allocator, but at a
> check point, all of the loan memory should be turned back.
> A typical using style:
>  -1. find a usable range by memblock_find_in_range(), said, [A,B]
>  -2. before calling a series of func, memblock_set_current_limit(A,B,true)
>  -3. call funcs
>  -4. memblock_find_in_range(A,B,B-A,1), if failed, then some memory is not
>      turned back.
>  -5. reset the original limit
> 
> E.g. in the case of hotmovable memory, some acpi routines should be called,
> and they are not allowed to own some movable memory. Although at present
> these functions do not consume memory, but later, if changed without
> awareness, they may do. With the above method, the allocation can be
> detected, and pr_warn() to ask people to resolve it.

To ensure there were that a sequence of function calls didn't create new
memblock allocations you can simply check the number of the reserved
regions before and after that sequence.

Still, I'm not sure it would be practical to try tracking what code that's called
from x86::setup_arch() did memory allocation.
Probably a better approach is to verify no memory ended up in the movable
areas after their extents are known.
 
> Signed-off-by: Pingfan Liu <kernelfans@xxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Borislav Petkov <bp@xxxxxxxxx>
> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
> Cc: Andy Lutomirski <luto@xxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> Cc: Len Brown <lenb@xxxxxxxxxx>
> Cc: Yinghai Lu <yinghai@xxxxxxxxxx>
> Cc: Tejun Heo <tj@xxxxxxxxxx>
> Cc: Chao Fan <fanc.fnst@xxxxxxxxxxxxxx>
> Cc: Baoquan He <bhe@xxxxxxxxxx>
> Cc: Juergen Gross <jgross@xxxxxxxx>
> Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
> Cc: Vlastimil Babka <vbabka@xxxxxxx>
> Cc: Michal Hocko <mhocko@xxxxxxxx>
> Cc: x86@xxxxxxxxxx
> Cc: linux-acpi@xxxxxxxxxxxxxxx
> Cc: linux-mm@xxxxxxxxx
> ---
>  arch/arm/mm/init.c              |  3 ++-
>  arch/arm/mm/mmu.c               |  4 ++--
>  arch/arm/mm/nommu.c             |  2 +-
>  arch/csky/kernel/setup.c        |  2 +-
>  arch/microblaze/mm/init.c       |  2 +-
>  arch/mips/kernel/setup.c        |  2 +-
>  arch/powerpc/mm/40x_mmu.c       |  6 ++++--
>  arch/powerpc/mm/44x_mmu.c       |  2 +-
>  arch/powerpc/mm/8xx_mmu.c       |  2 +-
>  arch/powerpc/mm/fsl_booke_mmu.c |  5 +++--
>  arch/powerpc/mm/hash_utils_64.c |  4 ++--
>  arch/powerpc/mm/init_32.c       |  2 +-
>  arch/powerpc/mm/pgtable-radix.c |  2 +-
>  arch/powerpc/mm/ppc_mmu_32.c    |  8 ++++++--
>  arch/powerpc/mm/tlb_nohash.c    |  6 ++++--
>  arch/unicore32/mm/mmu.c         |  2 +-
>  arch/x86/kernel/setup.c         |  2 +-
>  arch/xtensa/mm/init.c           |  2 +-
>  include/linux/memblock.h        | 10 +++++++---
>  mm/memblock.c                   | 23 ++++++++++++++++++-----
>  20 files changed, 59 insertions(+), 32 deletions(-)
> 
> diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
> index 32e4845..58a4342 100644
> --- a/arch/arm/mm/init.c
> +++ b/arch/arm/mm/init.c
> @@ -93,7 +93,8 @@ __tagtable(ATAG_INITRD2, parse_tag_initrd2);
>  static void __init find_limits(unsigned long *min, unsigned long *max_low,
>  			       unsigned long *max_high)
>  {
> -	*max_low = PFN_DOWN(memblock_get_current_limit());
> +	memblock_get_current_limit(NULL, max_low);
> +	*max_low = PFN_DOWN(*max_low);
>  	*min = PFN_UP(memblock_start_of_DRAM());
>  	*max_high = PFN_DOWN(memblock_end_of_DRAM());
>  }
> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
> index f5cc1cc..9025418 100644
> --- a/arch/arm/mm/mmu.c
> +++ b/arch/arm/mm/mmu.c
> @@ -1240,7 +1240,7 @@ void __init adjust_lowmem_bounds(void)
>  		}
>  	}
> 
> -	memblock_set_current_limit(memblock_limit);
> +	memblock_set_current_limit(0, memblock_limit, false);
>  }
> 
>  static inline void prepare_page_table(void)
> @@ -1625,7 +1625,7 @@ void __init paging_init(const struct machine_desc *mdesc)
> 
>  	prepare_page_table();
>  	map_lowmem();
> -	memblock_set_current_limit(arm_lowmem_limit);
> +	memblock_set_current_limit(0, arm_lowmem_limit, false);
>  	dma_contiguous_remap();
>  	early_fixmap_shutdown();
>  	devicemaps_init(mdesc);
> diff --git a/arch/arm/mm/nommu.c b/arch/arm/mm/nommu.c
> index 7d67c70..721535c 100644
> --- a/arch/arm/mm/nommu.c
> +++ b/arch/arm/mm/nommu.c
> @@ -138,7 +138,7 @@ void __init adjust_lowmem_bounds(void)
>  	adjust_lowmem_bounds_mpu();
>  	end = memblock_end_of_DRAM();
>  	high_memory = __va(end - 1) + 1;
> -	memblock_set_current_limit(end);
> +	memblock_set_current_limit(0, end, false);
>  }
> 
>  /*
> diff --git a/arch/csky/kernel/setup.c b/arch/csky/kernel/setup.c
> index dff8b89..e6f88bf 100644
> --- a/arch/csky/kernel/setup.c
> +++ b/arch/csky/kernel/setup.c
> @@ -100,7 +100,7 @@ static void __init csky_memblock_init(void)
> 
>  	highend_pfn = max_pfn;
>  #endif
> -	memblock_set_current_limit(PFN_PHYS(max_low_pfn));
> +	memblock_set_current_limit(0, PFN_PHYS(max_low_pfn), false);
> 
>  	dma_contiguous_reserve(0);
> 
> diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
> index b17fd8a..cee99da 100644
> --- a/arch/microblaze/mm/init.c
> +++ b/arch/microblaze/mm/init.c
> @@ -353,7 +353,7 @@ asmlinkage void __init mmu_init(void)
>  	/* Shortly after that, the entire linear mapping will be available */
>  	/* This will also cause that unflatten device tree will be allocated
>  	 * inside 768MB limit */
> -	memblock_set_current_limit(memory_start + lowmem_size - 1);
> +	memblock_set_current_limit(0, memory_start + lowmem_size - 1, false);
>  }
> 
>  /* This is only called until mem_init is done. */
> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index 8c6c48ed..62dabe1 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c
> @@ -862,7 +862,7 @@ static void __init arch_mem_init(char **cmdline_p)
>  	 * with memblock_reserve; memblock_alloc* can be used
>  	 * only after this point
>  	 */
> -	memblock_set_current_limit(PFN_PHYS(max_low_pfn));
> +	memblock_set_current_limit(0, PFN_PHYS(max_low_pfn), false);
> 
>  #ifdef CONFIG_PROC_VMCORE
>  	if (setup_elfcorehdr && setup_elfcorehdr_size) {
> diff --git a/arch/powerpc/mm/40x_mmu.c b/arch/powerpc/mm/40x_mmu.c
> index 61ac468..427bb56 100644
> --- a/arch/powerpc/mm/40x_mmu.c
> +++ b/arch/powerpc/mm/40x_mmu.c
> @@ -141,7 +141,7 @@ unsigned long __init mmu_mapin_ram(unsigned long top)
>  	 * coverage with normal-sized pages (or other reasons) do not
>  	 * attempt to allocate outside the allowed range.
>  	 */
> -	memblock_set_current_limit(mapped);
> +	memblock_set_current_limit(0, mapped, false);
> 
>  	return mapped;
>  }
> @@ -155,5 +155,7 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
>  	BUG_ON(first_memblock_base != 0);
> 
>  	/* 40x can only access 16MB at the moment (see head_40x.S) */
> -	memblock_set_current_limit(min_t(u64, first_memblock_size, 0x00800000));
> +	memblock_set_current_limit(0,
> +		min_t(u64, first_memblock_size, 0x00800000),
> +		false);
>  }
> diff --git a/arch/powerpc/mm/44x_mmu.c b/arch/powerpc/mm/44x_mmu.c
> index 12d9251..3cf127d 100644
> --- a/arch/powerpc/mm/44x_mmu.c
> +++ b/arch/powerpc/mm/44x_mmu.c
> @@ -225,7 +225,7 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
> 
>  	/* 44x has a 256M TLB entry pinned at boot */
>  	size = (min_t(u64, first_memblock_size, PPC_PIN_SIZE));
> -	memblock_set_current_limit(first_memblock_base + size);
> +	memblock_set_current_limit(0, first_memblock_base + size, false);
>  }
> 
>  #ifdef CONFIG_SMP
> diff --git a/arch/powerpc/mm/8xx_mmu.c b/arch/powerpc/mm/8xx_mmu.c
> index 01b7f51..c75bca6 100644
> --- a/arch/powerpc/mm/8xx_mmu.c
> +++ b/arch/powerpc/mm/8xx_mmu.c
> @@ -135,7 +135,7 @@ unsigned long __init mmu_mapin_ram(unsigned long top)
>  	 * attempt to allocate outside the allowed range.
>  	 */
>  	if (mapped)
> -		memblock_set_current_limit(mapped);
> +		memblock_set_current_limit(0, mapped, false);
> 
>  	block_mapped_ram = mapped;
> 
> diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
> index 080d49b..3be24b8 100644
> --- a/arch/powerpc/mm/fsl_booke_mmu.c
> +++ b/arch/powerpc/mm/fsl_booke_mmu.c
> @@ -252,7 +252,8 @@ void __init adjust_total_lowmem(void)
>  	pr_cont("%lu Mb, residual: %dMb\n", tlbcam_sz(tlbcam_index - 1) >> 20,
>  	        (unsigned int)((total_lowmem - __max_low_memory) >> 20));
> 
> -	memblock_set_current_limit(memstart_addr + __max_low_memory);
> +	memblock_set_current_limit(0,
> +		memstart_addr + __max_low_memory, false);
>  }
> 
>  void setup_initial_memory_limit(phys_addr_t first_memblock_base,
> @@ -261,7 +262,7 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
>  	phys_addr_t limit = first_memblock_base + first_memblock_size;
> 
>  	/* 64M mapped initially according to head_fsl_booke.S */
> -	memblock_set_current_limit(min_t(u64, limit, 0x04000000));
> +	memblock_set_current_limit(0, min_t(u64, limit, 0x04000000), false);
>  }
> 
>  #ifdef CONFIG_RELOCATABLE
> diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
> index 0cc7fbc..30fba80 100644
> --- a/arch/powerpc/mm/hash_utils_64.c
> +++ b/arch/powerpc/mm/hash_utils_64.c
> @@ -925,7 +925,7 @@ static void __init htab_initialize(void)
>  		BUG_ON(htab_bolt_mapping(base, base + size, __pa(base),
>  				prot, mmu_linear_psize, mmu_kernel_ssize));
>  	}
> -	memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
> +	memblock_set_current_limit(0, MEMBLOCK_ALLOC_ANYWHERE, false);
> 
>  	/*
>  	 * If we have a memory_limit and we've allocated TCEs then we need to
> @@ -1867,7 +1867,7 @@ void hash__setup_initial_memory_limit(phys_addr_t first_memblock_base,
>  			ppc64_rma_size = min_t(u64, ppc64_rma_size, 0x40000000);
> 
>  		/* Finally limit subsequent allocations */
> -		memblock_set_current_limit(ppc64_rma_size);
> +		memblock_set_current_limit(0, ppc64_rma_size, false);
>  	} else {
>  		ppc64_rma_size = ULONG_MAX;
>  	}
> diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c
> index 3e59e5d..863d710 100644
> --- a/arch/powerpc/mm/init_32.c
> +++ b/arch/powerpc/mm/init_32.c
> @@ -183,5 +183,5 @@ void __init MMU_init(void)
>  #endif
> 
>  	/* Shortly after that, the entire linear mapping will be available */
> -	memblock_set_current_limit(lowmem_end_addr);
> +	memblock_set_current_limit(0, lowmem_end_addr, false);
>  }
> diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c
> index 9311560..8cd5f2d 100644
> --- a/arch/powerpc/mm/pgtable-radix.c
> +++ b/arch/powerpc/mm/pgtable-radix.c
> @@ -603,7 +603,7 @@ void __init radix__early_init_mmu(void)
>  		radix_init_pseries();
>  	}
> 
> -	memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE);
> +	memblock_set_current_limit(0, MEMBLOCK_ALLOC_ANYWHERE, false);
> 
>  	radix_init_iamr();
>  	radix_init_pgtable();
> diff --git a/arch/powerpc/mm/ppc_mmu_32.c b/arch/powerpc/mm/ppc_mmu_32.c
> index f6f575b..80927ad 100644
> --- a/arch/powerpc/mm/ppc_mmu_32.c
> +++ b/arch/powerpc/mm/ppc_mmu_32.c
> @@ -283,7 +283,11 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
> 
>  	/* 601 can only access 16MB at the moment */
>  	if (PVR_VER(mfspr(SPRN_PVR)) == 1)
> -		memblock_set_current_limit(min_t(u64, first_memblock_size, 0x01000000));
> +		memblock_set_current_limit(0,
> +			min_t(u64, first_memblock_size, 0x01000000),
> +			false);
>  	else /* Anything else has 256M mapped */
> -		memblock_set_current_limit(min_t(u64, first_memblock_size, 0x10000000));
> +		memblock_set_current_limit(0,
> +			min_t(u64, first_memblock_size, 0x10000000),
> +			false);
>  }
> diff --git a/arch/powerpc/mm/tlb_nohash.c b/arch/powerpc/mm/tlb_nohash.c
> index ae5d568..d074362 100644
> --- a/arch/powerpc/mm/tlb_nohash.c
> +++ b/arch/powerpc/mm/tlb_nohash.c
> @@ -735,7 +735,7 @@ static void __init early_mmu_set_memory_limit(void)
>  		 * reduces the memory available to Linux.  We need to
>  		 * do this because highmem is not supported on 64-bit.
>  		 */
> -		memblock_enforce_memory_limit(linear_map_top);
> +		memblock_enforce_memory_limit(0, linear_map_top, false);
>  	}
>  #endif
> 
> @@ -792,7 +792,9 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base,
>  		ppc64_rma_size = min_t(u64, first_memblock_size, 0x40000000);
> 
>  	/* Finally limit subsequent allocations */
> -	memblock_set_current_limit(first_memblock_base + ppc64_rma_size);
> +	memblock_set_current_limit(0,
> +			first_memblock_base + ppc64_rma_size,
> +			false);
>  }
>  #else /* ! CONFIG_PPC64 */
>  void __init early_init_mmu(void)
> diff --git a/arch/unicore32/mm/mmu.c b/arch/unicore32/mm/mmu.c
> index 040a8c2..6d62529 100644
> --- a/arch/unicore32/mm/mmu.c
> +++ b/arch/unicore32/mm/mmu.c
> @@ -286,7 +286,7 @@ static void __init sanity_check_meminfo(void)
>  	int i, j;
> 
>  	lowmem_limit = __pa(vmalloc_min - 1) + 1;
> -	memblock_set_current_limit(lowmem_limit);
> +	memblock_set_current_limit(0, lowmem_limit, false);
> 
>  	for (i = 0, j = 0; i < meminfo.nr_banks; i++) {
>  		struct membank *bank = &meminfo.bank[j];
> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
> index dc8fc5d..a0122cd 100644
> --- a/arch/x86/kernel/setup.c
> +++ b/arch/x86/kernel/setup.c
> @@ -1130,7 +1130,7 @@ void __init setup_arch(char **cmdline_p)
>  		memblock_set_bottom_up(true);
>  #endif
>  	init_mem_mapping();
> -	memblock_set_current_limit(get_max_mapped());
> +	memblock_set_current_limit(0, get_max_mapped(), false);
> 
>  	idt_setup_early_pf();
> 
> diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c
> index 30a48bb..b924387 100644
> --- a/arch/xtensa/mm/init.c
> +++ b/arch/xtensa/mm/init.c
> @@ -60,7 +60,7 @@ void __init bootmem_init(void)
>  	max_pfn = PFN_DOWN(memblock_end_of_DRAM());
>  	max_low_pfn = min(max_pfn, MAX_LOW_PFN);
> 
> -	memblock_set_current_limit(PFN_PHYS(max_low_pfn));
> +	memblock_set_current_limit(0, PFN_PHYS(max_low_pfn), false);
>  	dma_contiguous_reserve(PFN_PHYS(max_low_pfn));
> 
>  	memblock_dump_all();
> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> index aee299a..49676f0 100644
> --- a/include/linux/memblock.h
> +++ b/include/linux/memblock.h
> @@ -88,6 +88,8 @@ struct memblock_type {
>   */
>  struct memblock {
>  	bool bottom_up;  /* is bottom up direction? */
> +	bool enforce_checking;
> +	phys_addr_t start_limit;
>  	phys_addr_t current_limit;
>  	struct memblock_type memory;
>  	struct memblock_type reserved;
> @@ -482,12 +484,14 @@ static inline void memblock_dump_all(void)
>   * memblock_set_current_limit - Set the current allocation limit to allow
>   *                         limiting allocations to what is currently
>   *                         accessible during boot
> - * @limit: New limit value (physical address)
> + * [start_limit, end_limit]: New limit value (physical address)
> + * enforcing: whether check against the limit boundary or not
>   */
> -void memblock_set_current_limit(phys_addr_t limit);
> +void memblock_set_current_limit(phys_addr_t start_limit,
> +	phys_addr_t end_limit, bool enforcing);
> 
> 
> -phys_addr_t memblock_get_current_limit(void);
> +bool memblock_get_current_limit(phys_addr_t *start, phys_addr_t *end);
> 
>  /*
>   * pfn conversion functions
> diff --git a/mm/memblock.c b/mm/memblock.c
> index 81ae63c..b792be0 100644
> --- a/mm/memblock.c
> +++ b/mm/memblock.c
> @@ -116,6 +116,8 @@ struct memblock memblock __initdata_memblock = {
>  #endif
> 
>  	.bottom_up		= false,
> +	.enforce_checking	= false,
> +	.start_limit		= 0,
>  	.current_limit		= MEMBLOCK_ALLOC_ANYWHERE,
>  };
> 
> @@ -261,8 +263,11 @@ phys_addr_t __init_memblock memblock_find_in_range_node(phys_addr_t size,
>  {
>  	phys_addr_t kernel_end, ret;
> 
> +	if (unlikely(memblock.enforce_checking)) {
> +		start = memblock.start_limit;
> +		end = memblock.current_limit;
>  	/* pump up @end */
> -	if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
> +	} else if (end == MEMBLOCK_ALLOC_ACCESSIBLE)
>  		end = memblock.current_limit;
> 
>  	/* avoid allocating the first page */
> @@ -1826,14 +1831,22 @@ void __init_memblock memblock_trim_memory(phys_addr_t align)
>  	}
>  }
> 
> -void __init_memblock memblock_set_current_limit(phys_addr_t limit)
> +void __init_memblock memblock_set_current_limit(phys_addr_t start,
> +	phys_addr_t end, bool enforcing)
>  {
> -	memblock.current_limit = limit;
> +	memblock.start_limit = start;
> +	memblock.current_limit = end;
> +	memblock.enforce_checking = enforcing;
>  }
> 
> -phys_addr_t __init_memblock memblock_get_current_limit(void)
> +bool __init_memblock memblock_get_current_limit(phys_addr_t *start,
> +	phys_addr_t *end)
>  {
> -	return memblock.current_limit;
> +	if (start)
> +		*start = memblock.start_limit;
> +	if (end)
> +		*end = memblock.current_limit;
> +	return memblock.enforce_checking;
>  }
> 
>  static void __init_memblock memblock_dump(struct memblock_type *type)
> -- 
> 2.7.4
> 

-- 
Sincerely yours,
Mike.