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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/huge_memory.c | |
| parent | c01d5b300774d130a24d787825b01eb24e6e20cb (diff) | |
| download | linux-800d8c63b2e989c2e349632d1648119bf5862f01.tar.bz2 | |
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/huge_memory.c')
| -rw-r--r-- | mm/huge_memory.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/mm/huge_memory.c b/mm/huge_memory.c index cabd53dac5b9..0f58460cd69c 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3316,6 +3316,8 @@ static void __split_huge_page(struct page *page, struct list_head *list, if (head[i].index >= end) { __ClearPageDirty(head + i); __delete_from_page_cache(head + i, NULL); + if (IS_ENABLED(CONFIG_SHMEM) && PageSwapBacked(head)) + shmem_uncharge(head->mapping->host, 1); put_page(head + i); } } |