Re: [PATCH v2] dynamic_debug: Restore dev_dbg functionality, optimize stack

On Tue, 2012-07-31 at 14:55 -0700, Andrew Morton wrote:

On Sat, 28 Jul 2012 00:55:07 -0700
Joe Perches [off-list ref] wrote:

quoted

commit c4e00daaa9 ("driver-core: extend dev_printk() to pass structured data")
changed __dev_printk and broke dynamic-debug's ability to control the
dynamic prefix of dev_dbg(dev,..).

dynamic_emit_prefix() adds "[tid] module:func:line:" to the output and
those additions got lost.

In addition, the current dynamic debug code uses up to 3 recursion
levels via %pV.  This can consume quite a bit of stack.  Directly
call printk_emit to reduce the recursion depth.

[]

quoted

Changes in v2:

o Fix dynamic_emit_prefix to always initialize output
o Call create_syslog_header and emit_printk from__netdev_printk and
  eliminate call to dev_printk to remove another recursion via %pV

This one causes an oops-on-boot
(http://ozlabs.org/~akpm/stuff/IMG_20120731_144047.jpg).  v1 didn't do
that.

config: http://ozlabs.org/~akpm/stuff/config-akpm2

Thanks.  I'll fix it when I can.
Expect a week or so delay though.

I'm a bit busy on other projects and this one seems to
require additional testing.

cheers, Joe