From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
For now we try to grab a huge cache page if gfp_mask has __GFP_COMP.
It's probably to weak condition and need to be reworked later.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
fs/libfs.c | 50 ++++++++++++++++++++++++++++++++++++-----------
include/linux/pagemap.h | 8 ++++++++
2 files changed, 47 insertions(+), 11 deletions(-)
diff --git a/fs/libfs.c b/fs/libfs.c
index 916da8c..ce807fe 100644
--- a/fs/libfs.c
+++ b/fs/libfs.c
@@ -383,7 +383,7 @@ EXPORT_SYMBOL(simple_setattr);
int simple_readpage(struct file *file, struct page *page)
{
- clear_highpage(page);
+ clear_pagecache_page(page);
flush_dcache_page(page);
SetPageUptodate(page);
unlock_page(page);
@@ -394,21 +394,44 @@ int simple_write_begin(struct file *file, struct address_space *mapping,
loff_t pos, unsigned len, unsigned flags,
struct page **pagep, void **fsdata)
{
- struct page *page;
+ struct page *page = NULL;
pgoff_t index;
index = pos >> PAGE_CACHE_SHIFT;
- page = grab_cache_page_write_begin(mapping, index, flags);
+ /* XXX: too weak condition? */
+ if (mapping_can_have_hugepages(mapping)) {
+ page = grab_cache_page_write_begin(mapping,
+ index & ~HPAGE_CACHE_INDEX_MASK,
+ flags | AOP_FLAG_TRANSHUGE);
+ /* fallback to small page */
+ if (!page) {
+ unsigned long offset;
+ offset = pos & ~PAGE_CACHE_MASK;
+ len = min_t(unsigned long,
+ len, PAGE_CACHE_SIZE - offset);
+ }
+ BUG_ON(page && !PageTransHuge(page));
+ }
+ if (!page)
+ page = grab_cache_page_write_begin(mapping, index, flags);
if (!page)
return -ENOMEM;
-
*pagep = page;
- if (!PageUptodate(page) && (len != PAGE_CACHE_SIZE)) {
- unsigned from = pos & (PAGE_CACHE_SIZE - 1);
-
- zero_user_segments(page, 0, from, from + len, PAGE_CACHE_SIZE);
+ if (!PageUptodate(page)) {
+ unsigned from;
+
+ if (PageTransHuge(page) && len != HPAGE_PMD_SIZE) {
+ from = pos & ~HPAGE_PMD_MASK;
+ zero_huge_user_segment(page, 0, from);
+ zero_huge_user_segment(page,
+ from + len, HPAGE_PMD_SIZE);
+ } else if (len != PAGE_CACHE_SIZE) {
+ from = pos & ~PAGE_CACHE_MASK;
+ zero_user_segments(page, 0, from,
+ from + len, PAGE_CACHE_SIZE);
+ }
}
return 0;
}
@@ -443,9 +466,14 @@ int simple_write_end(struct file *file, struct address_space *mapping,
/* zero the stale part of the page if we did a short copy */
if (copied < len) {
- unsigned from = pos & (PAGE_CACHE_SIZE - 1);
-
- zero_user(page, from + copied, len - copied);
+ unsigned from;
+ if (PageTransHuge(page)) {
+ from = pos & ~HPAGE_PMD_MASK;
+ zero_huge_user(page, from + copied, len - copied);
+ } else {
+ from = pos & ~PAGE_CACHE_MASK;
+ zero_user(page, from + copied, len - copied);
+ }
}
if (!PageUptodate(page))
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 8feeecc..462fcca 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -579,4 +579,12 @@ static inline int add_to_page_cache(struct page *page,
return error;
}
+static inline void clear_pagecache_page(struct page *page)
+{
+ if (PageTransHuge(page))
+ zero_huge_user(page, 0, HPAGE_PMD_SIZE);
+ else
+ clear_highpage(page);
+}
+
#endif /* _LINUX_PAGEMAP_H */
--
1.7.10.4
--
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