From: David Chinner <redacted>
Date: Thu, 23 Nov 2006 12:18:09 +1100

So, assuming the stacks less than 32 bytes are 32 bytes, we've got
1380 bytes in the XFS stack there, 

On sparc64 just the XFS parts of the backtrace would be a minimum of
2816 bytes (each function has a minimum 8 * 16 byte stack frame, and
there are about 22 calls in that trace).  It's probably a lot more
with local variables and such.

It's way too much.  You guys have to fix this stuff.

If TCP's full send and receive path can be done in less function
calls, XFS can allocate blocks in less too.

I would even say 10 function calls deep to allocate file blocks
is overkill, but 22 it just astronomically bad.