diff options
| author | Cheng Li <lic121@chinatelecom.cn> | 2022-09-09 07:31:09 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2022-10-03 14:03:08 -0700 |
| commit | 14455eabd8404a503dc8e80cd8ce185e96a94b22 (patch) | |
| tree | ebe035ca739c4efeecb5c1679aeb839db43ab101 /mm/memory.c | |
| parent | 0d83b2d89dbfad17b62d4e7fb8f0b0525ba1a204 (diff) | |
mm: use nth_page instead of mem_map_offset mem_map_next
To handle the discontiguous case, mem_map_next() has a parameter named
`offset`. As a function caller, one would be confused why "get next
entry" needs a parameter named "offset". The other drawback of
mem_map_next() is that the callers must take care of the map between
parameter "iter" and "offset", otherwise we may get an hole or duplication
during iteration. So we use nth_page instead of mem_map_next.
And replace mem_map_offset with nth_page() per Matthew's comments.
Link: https://lkml.kernel.org/r/1662708669-9395-1-git-send-email-lic121@chinatelecom.cn
Signed-off-by: Cheng Li <lic121@chinatelecom.cn>
Fixes: 69d177c2fc70 ("hugetlbfs: handle pages higher order than MAX_ORDER")
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
| -rw-r--r-- | mm/memory.c | 21 |
1 files changed, 10 insertions, 11 deletions
diff --git a/mm/memory.c b/mm/memory.c index d671ad367d67..c01c12500169 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -5690,11 +5690,11 @@ static void clear_gigantic_page(struct page *page, unsigned int pages_per_huge_page) { int i; - struct page *p = page; + struct page *p; might_sleep(); - for (i = 0; i < pages_per_huge_page; - i++, p = mem_map_next(p, page, i)) { + for (i = 0; i < pages_per_huge_page; i++) { + p = nth_page(page, i); cond_resched(); clear_user_highpage(p, addr + i * PAGE_SIZE); } @@ -5730,13 +5730,12 @@ static void copy_user_gigantic_page(struct page *dst, struct page *src, struct page *dst_base = dst; struct page *src_base = src; - for (i = 0; i < pages_per_huge_page; ) { + for (i = 0; i < pages_per_huge_page; i++) { + dst = nth_page(dst_base, i); + src = nth_page(src_base, i); + cond_resched(); copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma); - - i++; - dst = mem_map_next(dst, dst_base, i); - src = mem_map_next(src, src_base, i); } } @@ -5783,10 +5782,10 @@ long copy_huge_page_from_user(struct page *dst_page, void *page_kaddr; unsigned long i, rc = 0; unsigned long ret_val = pages_per_huge_page * PAGE_SIZE; - struct page *subpage = dst_page; + struct page *subpage; - for (i = 0; i < pages_per_huge_page; - i++, subpage = mem_map_next(subpage, dst_page, i)) { + for (i = 0; i < pages_per_huge_page; i++) { + subpage = nth_page(dst_page, i); if (allow_pagefault) page_kaddr = kmap(subpage); else |