Re: [PATCH 11/15] memblock: reduce number of parameters in for_each_mem_range()

Baoquan He
2020-07-30T02:22:30Z

On 07/28/20 at 08:11am, Mike Rapoport wrote:
> From: Mike Rapoport <rppt@linux.ibm.com>
>
> Currently for_each_mem_range() iterator is the most generic way to traverse
> memblock regions. As such, it has 8 parameters and it is hardly convenient
> to users. Most users choose to utilize one of its wrappers and the only
> user that actually needs most of the parameters outside memblock is s390
> crash dump implementation.
>
> To avoid yet another naming for memblock iterators, rename the existing
> for_each_mem_range() to __for_each_mem_range() and add a new
> for_each_mem_range() wrapper with only index, start and end parameters.
>
> The new wrapper nicely fits into init_unavailable_mem() and will be used in
> upcoming changes to simplify memblock traversals.
>
> Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
> ---
> .clang-format | 1 +
> arch/arm64/kernel/machine_kexec_file.c | 6 ++----
> arch/s390/kernel/crash_dump.c | 8 ++++----
> include/linux/memblock.h | 18 ++++++++++++++----
> mm/page_alloc.c | 3 +--
> 5 files changed, 22 insertions(+), 14 deletions(-)

Reviewed-by: Baoquan He <bhe@redhat.com>

>
> diff --git a/.clang-format b/.clang-format
> index a0a96088c74f..52ededab25ce 100644
> --- a/.clang-format
> +++ b/.clang-format
> @@ -205,6 +205,7 @@ ForEachMacros:
> - 'for_each_memblock_type'
> - 'for_each_memcg_cache_index'
> - 'for_each_mem_pfn_range'
> + - '__for_each_mem_range'
> - 'for_each_mem_range'
> - 'for_each_mem_range_rev'
> - 'for_each_migratetype_order'
> diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
> index 361a1143e09e..5b0e67b93cdc 100644
> --- a/arch/arm64/kernel/machine_kexec_file.c
> +++ b/arch/arm64/kernel/machine_kexec_file.c
> @@ -215,8 +215,7 @@ static int prepare_elf_headers(void **addr, unsigned long *sz)
> phys_addr_t start, end;
>
> nr_ranges = 1; /* for exclusion of crashkernel region */
> - for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE,
> - MEMBLOCK_NONE, &start, &end, NULL)
> + for_each_mem_range(i, &start, &end)
> nr_ranges++;
>
> cmem = kmalloc(struct_size(cmem, ranges, nr_ranges), GFP_KERNEL);
> @@ -225,8 +224,7 @@ static int prepare_elf_headers(void **addr, unsigned long *sz)
>
> cmem->max_nr_ranges = nr_ranges;
> cmem->nr_ranges = 0;
> - for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE,
> - MEMBLOCK_NONE, &start, &end, NULL) {
> + for_each_mem_range(i, &start, &end) {
> cmem->ranges[cmem->nr_ranges].start = start;
> cmem->ranges[cmem->nr_ranges].end = end - 1;
> cmem->nr_ranges++;
> diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
> index f96a5857bbfd..e28085c725ff 100644
> --- a/arch/s390/kernel/crash_dump.c
> +++ b/arch/s390/kernel/crash_dump.c
> @@ -549,8 +549,8 @@ static int get_mem_chunk_cnt(void)
> int cnt = 0;
> u64 idx;
>
> - for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
> - MEMBLOCK_NONE, NULL, NULL, NULL)
> + __for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
> + MEMBLOCK_NONE, NULL, NULL, NULL)
> cnt++;
> return cnt;
> }
> @@ -563,8 +563,8 @@ static void loads_init(Elf64_Phdr *phdr, u64 loads_offset)
> phys_addr_t start, end;
> u64 idx;
>
> - for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
> - MEMBLOCK_NONE, &start, &end, NULL) {
> + __for_each_mem_range(idx, &memblock.physmem, &oldmem_type, NUMA_NO_NODE,
> + MEMBLOCK_NONE, &start, &end, NULL) {
> phdr->p_filesz = end - start;
> phdr->p_type = PT_LOAD;
> phdr->p_offset = start;
> diff --git a/include/linux/memblock.h b/include/linux/memblock.h
> index e6a23b3db696..d70c2835e913 100644
> --- a/include/linux/memblock.h
> +++ b/include/linux/memblock.h
> @@ -142,7 +142,7 @@ void __next_reserved_mem_region(u64 *idx, phys_addr_t *out_start,
> void __memblock_free_late(phys_addr_t base, phys_addr_t size);
>
> /**
> - * for_each_mem_range - iterate through memblock areas from type_a and not
> + * __for_each_mem_range - iterate through memblock areas from type_a and not
> * included in type_b. Or just type_a if type_b is NULL.
> * @i: u64 used as loop variable
> * @type_a: ptr to memblock_type to iterate
> @@ -153,7 +153,7 @@ void __memblock_free_late(phys_addr_t base, phys_addr_t size);
> * @p_end: ptr to phys_addr_t for end address of the range, can be %NULL
> * @p_nid: ptr to int for nid of the range, can be %NULL
> */
> -#define for_each_mem_range(i, type_a, type_b, nid, flags, \
> +#define __for_each_mem_range(i, type_a, type_b, nid, flags, \
> p_start, p_end, p_nid) \
> for (i = 0, __next_mem_range(&i, nid, flags, type_a, type_b, \
> p_start, p_end, p_nid); \
> @@ -182,6 +182,16 @@ void __memblock_free_late(phys_addr_t base, phys_addr_t size);
> __next_mem_range_rev(&i, nid, flags, type_a, type_b, \
> p_start, p_end, p_nid))
>
> +/**
> + * for_each_mem_range - iterate through memory areas.
> + * @i: u64 used as loop variable
> + * @p_start: ptr to phys_addr_t for start address of the range, can be %NULL
> + * @p_end: ptr to phys_addr_t for end address of the range, can be %NULL
> + */
> +#define for_each_mem_range(i, p_start, p_end) \
> + __for_each_mem_range(i, &memblock.memory, NULL, NUMA_NO_NODE, \
> + MEMBLOCK_NONE, p_start, p_end, NULL)
> +
> /**
> * for_each_reserved_mem_region - iterate over all reserved memblock areas
> * @i: u64 used as loop variable
> @@ -287,8 +297,8 @@ int __init deferred_page_init_max_threads(const struct cpumask *node_cpumask);
> * soon as memblock is initialized.
> */
> #define for_each_free_mem_range(i, nid, flags, p_start, p_end, p_nid) \
> - for_each_mem_range(i, &memblock.memory, &memblock.reserved, \
> - nid, flags, p_start, p_end, p_nid)
> + __for_each_mem_range(i, &memblock.memory, &memblock.reserved, \
> + nid, flags, p_start, p_end, p_nid)
>
> /**
> * for_each_free_mem_range_reverse - rev-iterate through free memblock areas
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index e028b87ce294..95af111d69d3 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -6972,8 +6972,7 @@ static void __init init_unavailable_mem(void)
> * Loop through unavailable ranges not covered by memblock.memory.
> */
> pgcnt = 0;
> - for_each_mem_range(i, &memblock.memory, NULL,
> - NUMA_NO_NODE, MEMBLOCK_NONE, &start, &end, NULL) {
> + for_each_mem_range(i, &start, &end) {
> if (next < start)
> pgcnt += init_unavailable_range(PFN_DOWN(next),
> PFN_UP(start));
> --
> 2.26.2