[PATCHv2 16/41] filemap: allocate huge page in pagecache_get_page(), if allowed
From: Kirill A. Shutemov <hidden>
Date: 2016-08-12 18:37:59
Also in:
linux-ext4, linux-fsdevel, linux-mm, lkml
Subsystem:
memory management, page cache, the rest · Maintainers:
Andrew Morton, Matthew Wilcox, Jan Kara, Linus Torvalds
Write path allocate pages using pagecache_get_page(). We should be able to allocate huge pages there, if it's allowed. As usually, fallback to small pages, if failed. Signed-off-by: Kirill A. Shutemov <redacted> --- mm/filemap.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/mm/filemap.c b/mm/filemap.c
index 9d7d70b265d4..93fa97f143ab 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c@@ -1310,13 +1310,16 @@ repeat: no_page: if (!page && (fgp_flags & FGP_CREAT)) { + pgoff_t hoffset; int err; if ((fgp_flags & FGP_WRITE) && mapping_cap_account_dirty(mapping)) gfp_mask |= __GFP_WRITE; if (fgp_flags & FGP_NOFS) gfp_mask &= ~__GFP_FS; - page = __page_cache_alloc(gfp_mask); + page = page_cache_alloc_huge(mapping, offset, gfp_mask); +no_huge: if (!page) + page = __page_cache_alloc(gfp_mask); if (!page) return NULL;
@@ -1327,14 +1330,25 @@ no_page: if (fgp_flags & FGP_ACCESSED) __SetPageReferenced(page); - err = add_to_page_cache_lru(page, mapping, offset, + if (PageTransHuge(page)) + hoffset = round_down(offset, HPAGE_PMD_NR); + else + hoffset = offset; + + err = add_to_page_cache_lru(page, mapping, hoffset, gfp_mask & GFP_RECLAIM_MASK); if (unlikely(err)) { + if (PageTransHuge(page)) { + put_page(page); + page = NULL; + goto no_huge; + } put_page(page); page = NULL; if (err == -EEXIST) goto repeat; } + page += offset - hoffset; } return page;
--
2.8.1