For now we try to grab a huge cache page if the minimum requirements have been
satisfied.
Signed-off-by: Ning Qu <quning@xxxxxxxxx>
---
mm/shmem.c | 31 ++++++++++++++++++++++++++-----
1 file changed, 26 insertions(+), 5 deletions(-)
diff --git a/mm/shmem.c b/mm/shmem.c
index 2fc450d..0a423a9 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1640,8 +1640,21 @@ shmem_write_begin(struct file *file, struct address_space *mapping,
struct inode *inode = mapping->host;
pgoff_t index = pos >> PAGE_CACHE_SHIFT;
gfp_t gfp = mapping_gfp_mask(inode->i_mapping);
+ int ret = 0;
+ int getpage_flags = 0;
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE_PAGECACHE
+ /*
+ * Do not allocate a huge page in the first huge page range in page
+ * cache. This way we can avoid most small files overhead.
+ */
+ if (pos >= HPAGE_PMD_SIZE)
+ getpage_flags |= AOP_FLAG_TRANSHUGE;
+#endif
+ ret = shmem_getpage(inode, index, pagep, SGP_WRITE, gfp,
+ getpage_flags, NULL);
- return shmem_getpage(inode, index, pagep, SGP_WRITE, gfp, 0, NULL);
+ return ret;
}
static int
@@ -1655,10 +1668,18 @@ shmem_write_end(struct file *file, struct address_space *mapping,
i_size_write(inode, pos + copied);
if (!PageUptodate(page)) {
- if (copied < PAGE_CACHE_SIZE) {
- unsigned from = pos & (PAGE_CACHE_SIZE - 1);
- zero_user_segments(page, 0, from,
- from + copied, PAGE_CACHE_SIZE);
+ if (copied < len) {
+ unsigned from;
+ if (PageTransHugeCache(page)) {
+ from = pos & ~HPAGE_PMD_MASK;
+ zero_huge_user(page, 0, from);
+ zero_huge_user(page, from + copied,
+ HPAGE_PMD_SIZE);
+ } else {
+ from = pos & ~PAGE_CACHE_MASK;
+ zero_user_segments(page, 0, from,
+ from + copied, PAGE_CACHE_SIZE);
+ }
}
SetPageUptodate(page);
}
--
1.8.4
--
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