Re: [STACK] >3k call path in ide

[Andrew Morton <akpm@osdl.org>]

Jörn Engel <joern@wohnheim.fh-wedel.de> wrote:
>
>  Andrew, what do you thing about the patch below for sync_inodes_sb()?
>  It's stack consumption is reduced from 308 to 64, at the cost of one
>  more function call.

Like this:

--- 25/fs/fs-writeback.c~sync_inodes_sb-stack-reduction	2004-06-09 12:25:57.111389456 -0700
+++ 25-akpm/fs/fs-writeback.c	2004-06-09 12:25:57.115388848 -0700
@@ -433,15 +433,15 @@ restart:
  */
 void sync_inodes_sb(struct super_block *sb, int wait)
 {
-	struct page_state ps;
 	struct writeback_control wbc = {
 		.sync_mode	= wait ? WB_SYNC_ALL : WB_SYNC_HOLD,
 	};
+	unsigned long nr_dirty = read_page_state(nr_dirty);
+	unsigned long nr_unstable = read_page_state(nr_unstable);
 
-	get_page_state(&ps);
-	wbc.nr_to_write = ps.nr_dirty + ps.nr_unstable +
+	wbc.nr_to_write = nr_dirty + nr_unstable +
 			(inodes_stat.nr_inodes - inodes_stat.nr_unused) +
-			ps.nr_dirty + ps.nr_unstable;
+			nr_dirty + nr_unstable;
 	wbc.nr_to_write += wbc.nr_to_write / 2;		/* Bit more for luck */
 	spin_lock(&inode_lock);
 	sync_sb_inodes(sb, &wbc);
_