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| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2016-07-26 15:26:18 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-26 16:19:19 -0700 |
| commit | 800d8c63b2e989c2e349632d1648119bf5862f01 (patch) | |
| tree | 8f72ce10bcdc01f17a5e8f2197ae4858fbab6bd4 /mm/filemap.c | |
| parent | c01d5b300774d130a24d787825b01eb24e6e20cb (diff) | |
| download | linux-800d8c63b2e989c2e349632d1648119bf5862f01.tar.gz linux-800d8c63b2e989c2e349632d1648119bf5862f01.tar.xz | |
shmem: add huge pages support
Here's basic implementation of huge pages support for shmem/tmpfs.
It's all pretty streight-forward:
- shmem_getpage() allcoates huge page if it can and try to inserd into
radix tree with shmem_add_to_page_cache();
- shmem_add_to_page_cache() puts the page onto radix-tree if there's
space for it;
- shmem_undo_range() removes huge pages, if it fully within range.
Partial truncate of huge pages zero out this part of THP.
This have visible effect on fallocate(FALLOC_FL_PUNCH_HOLE)
behaviour. As we don't really create hole in this case,
lseek(SEEK_HOLE) may have inconsistent results depending what
pages happened to be allocated.
- no need to change shmem_fault: core-mm will map an compound page as
huge if VMA is suitable;
Link: http://lkml.kernel.org/r/1466021202-61880-30-git-send-email-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/filemap.c')
| -rw-r--r-- | mm/filemap.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/mm/filemap.c b/mm/filemap.c index 21508ea25717..e90c1543ec2d 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -219,8 +219,13 @@ void __delete_from_page_cache(struct page *page, void *shadow) /* hugetlb pages do not participate in page cache accounting. */ if (!PageHuge(page)) __mod_zone_page_state(page_zone(page), NR_FILE_PAGES, -nr); - if (PageSwapBacked(page)) + if (PageSwapBacked(page)) { __mod_zone_page_state(page_zone(page), NR_SHMEM, -nr); + if (PageTransHuge(page)) + __dec_zone_page_state(page, NR_SHMEM_THPS); + } else { + VM_BUG_ON_PAGE(PageTransHuge(page) && !PageHuge(page), page); + } /* * At this point page must be either written or cleaned by truncate. |