Re: [PATCH] add timing information to printk messages

[Tony Luck]

> Here's a little patch which is useful for showing timing information for
> kernel bootup activities.
> 
> This patch adds a new Kconfig option under "Kernel Hacking" and a new
> option for the kernel command line.  It also provides a script for
> showing delta information.

I'm seeing some odd output with CONFIG_PRINTK_TIME=y during boot.  When
it is set to "no", I see this from "dmesg":

Total of 4 processors activated (7168.96 BogoMIPS).
CPU0 attaching sched-domain:
 domain 0: span f
  groups: 1 2 4 8
CPU1 attaching sched-domain:
 domain 0: span f
  groups: 2 4 8 1
CPU2 attaching sched-domain:
 domain 0: span f
  groups: 4 8 1 2
CPU3 attaching sched-domain:
 domain 0: span f
  groups: 8 1 2 4

Setting CONFIG_PRINTK_TIME=y I see (the "<NUL>" pieces are actually
each a single ASCII '\0' character):

[    0.240887] Total of 4 processors activated (7168.96 BogoMIPS).
[    0.240926] CPU0 attaching sched-domain:
[    0.240930] <NUL>PU0 attaching sched-domain:
[    0.240933]  domain 0: span f
[    0.240967] <NUL> f
[    0.240969]   groups: 1 2 4 8
[    0.241024] CPU1 attaching sched-domain:
[    0.241027] <NUL>PU1 attaching sched-domain:
[    0.241030]  domain 0: span f
[    0.241063] <NUL> f
[    0.241065]   groups: 2 4 8 1
[    0.241146] CPU2 attaching sched-domain:
[    0.241149] <NUL>PU2 attaching sched-domain:
[    0.241151]  domain 0: span f
[    0.241186] <NUL> f
[    0.241188]   groups: 4 8 1 2
[    0.241267] CPU3 attaching sched-domain:
[    0.241270] <NUL>PU3 attaching sched-domain:
[    0.241273]  domain 0: span f
[    0.241307] <NUL> f
[    0.241309]   groups: 8 1 2 4

At first I thought that the lines that begin with whitespace were causing
the confusion, but there are other lines during boot that are ok.

[This is on an ia64 system ... but these messages come from generic kern/sched.c]

-Tony
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