Re: [PATCH+discussion] symlink recursion

[David Mosberger]

>>>>> On Wed, 19 Jun 2002 11:55:23 -0700 (PDT), Linus Torvalds <[e-mail]> said:

  Linus> Yes. But did you look at the stack frames of those things?
  Linus> It's something like 16 bytes for ext2_follow_link (it just
  Linus> calls directly back to the VFS layer), 20 bytes for
  Linus> vfs_follow_link(), and 56 for link_path_walk.

  Linux> ...

  Linus> But there are other numbers, like performance (sometimes
  Linus> linearizing recursion loses, sometimes it wins), or somebody
  Linus> doing the math on ia-64 and showing that the 100 bytes/level
  Linus> on x86 is actually more like 2kB on ia-64 and totally
  Linus> unacceptable.

Just to avoid starting false rumours: on ia-64, I see the following
(2.4.18, with gcc3.1):

	- ext2_follow_link():	 16 bytes/frame
	- vfs_follow_link():	 56 bytes/frame
	- link_path_walk():	128 bytes/frame
	---------------------	---------------
	total:			200 bytes/frame

Just about in line with what you'd expect given that registers are 64 bits.

	--david