From d2a97a4e99ff0ffdccd1fc46f22fb34270ef1e56 Mon Sep 17 00:00:00 2001 From: Steven Whitehouse Date: Wed, 28 Jul 2010 17:56:23 +0100 Subject: GFS2: Use kmalloc when possible for ->readdir() If we don't need a huge amount of memory in ->readdir() then we can use kmalloc rather than vmalloc to allocate it. This should cut down on the greater overheads associated with vmalloc for smaller directories. We may be able to eliminate vmalloc entirely at some stage, but this is easy to do right away. Also using GFP_NOFS to avoid any issues wrt to deleting inodes while under a glock, and suggestion from Linus to factor out the alloc/dealloc. I've given this a test with a variety of different sized directories and it seems to work ok. Cc: Andrew Morton Cc: Nick Piggin Cc: Prarit Bhargava Signed-off-by: Steven Whitehouse Signed-off-by: Linus Torvalds --- fs/gfs2/dir.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) (limited to 'fs') diff --git a/fs/gfs2/dir.c b/fs/gfs2/dir.c index 26ca3361a8bc..6b48d7c268b2 100644 --- a/fs/gfs2/dir.c +++ b/fs/gfs2/dir.c @@ -1231,6 +1231,25 @@ static int do_filldir_main(struct gfs2_inode *dip, u64 *offset, return 0; } +static void *gfs2_alloc_sort_buffer(unsigned size) +{ + void *ptr = NULL; + + if (size < KMALLOC_MAX_SIZE) + ptr = kmalloc(size, GFP_NOFS | __GFP_NOWARN); + if (!ptr) + ptr = __vmalloc(size, GFP_NOFS, PAGE_KERNEL); + return ptr; +} + +static void gfs2_free_sort_buffer(void *ptr) +{ + if (is_vmalloc_addr(ptr)) + vfree(ptr); + else + kfree(ptr); +} + static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque, filldir_t filldir, int *copied, unsigned *depth, u64 leaf_no) @@ -1271,7 +1290,7 @@ static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque, * 99 is the maximum number of entries that can fit in a single * leaf block. */ - larr = vmalloc((leaves + entries + 99) * sizeof(void *)); + larr = gfs2_alloc_sort_buffer((leaves + entries + 99) * sizeof(void *)); if (!larr) goto out; darr = (const struct gfs2_dirent **)(larr + leaves); @@ -1282,7 +1301,7 @@ static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque, do { error = get_leaf(ip, lfn, &bh); if (error) - goto out_kfree; + goto out_free; lf = (struct gfs2_leaf *)bh->b_data; lfn = be64_to_cpu(lf->lf_next); if (lf->lf_entries) { @@ -1291,7 +1310,7 @@ static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque, gfs2_dirent_gather, NULL, &g); error = PTR_ERR(dent); if (IS_ERR(dent)) - goto out_kfree; + goto out_free; if (entries2 != g.offset) { fs_warn(sdp, "Number of entries corrupt in dir " "leaf %llu, entries2 (%u) != " @@ -1300,7 +1319,7 @@ static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque, entries2, g.offset); error = -EIO; - goto out_kfree; + goto out_free; } error = 0; larr[leaf++] = bh; @@ -1312,10 +1331,10 @@ static int gfs2_dir_read_leaf(struct inode *inode, u64 *offset, void *opaque, BUG_ON(entries2 != entries); error = do_filldir_main(ip, offset, opaque, filldir, darr, entries, copied); -out_kfree: +out_free: for(i = 0; i < leaf; i++) brelse(larr[i]); - vfree(larr); + gfs2_free_sort_buffer(larr); out: return error; } -- cgit v1.2.3