Re: [RFC PATCH] cmdline: Hide "debug" from /proc/cmdline

Borislav Petkov
2014-04-03T11:23:33Z

On Wed, Apr 02, 2014 at 06:47:57PM -0700, Linus Torvalds wrote:
> Whether it actually fixes the problem that Borislav had is
> questionable, of course. For all I know, systemd debug mode generates
> so much data in *other* ways and then causes feedback loops with
> the kernel debugging that this patch is totally immaterial, and
> dmesg was never the main issue. But unlike the "hide 'debug' from
> /proc/cmdline", I think this patch at least _conceptually_ makes a lot
> of sense, even if systemd gets fixed, so ...
>
> Borislav?

Yes, ratelimiting makes the box actually boot all the way. Here's how it
looks like:

^MLoading Linux 3.12.16-boris-00441-g60dc93e99a75-dirty ...
^MLoading initial ramdisk ...
^M[ 0.000000] Initializing cgroup subsys cpuset
[ 0.000000] Initializing cgroup subsys cpu
[ 0.000000] Initializing cgroup subsys cpuacct
[ 0.000000] Linux version 3.12.16-boris-00441-g60dc93e99a75-dirty (gcc version 4.3.4 [gcc-4_3-branch revision 152973] (SUSE Linux) ) #11 SMP Thu Apr 3 10:19:49 CEST 2014
[ 0.000000] Command line: BOOT_IMAGE=/@/boot/vmlinuz-3.12.16-boris-00441-g60dc93e99a75-dirty root=UUID=5f1a28cf-d910-
4ed0-85ac-0113d43e553f rootflags=subvol=@ resume=/dev/disk/by-uuid/45671aef-cef3-4fcd-9087-7d4f3f81aa70 splash=off showo
pts crashkernel=256M-:128M pci=hpiosize=0 pci=hpmemsize=4m pciehp.pciehp_force=1 notsc mem=0x40000000000 loop.max_loop=6
4 log_buf_len=16M console=tty0 console=ttyS0,38400n8 ignore_loglevel debug
^^^^^

We haz the "debug" thing on.

...

Here we go:

[ 50.636000] be2net 0000:db:00.0: irq 102 for MSI/MSI-X
[ 50.636000] be2net 0000:db:00.0: irq 103 for MSI/MSI-X
[ 50.636000] be2net 0000:db:00.0: irq 104 for MSI/MSI-X
[ 50.636000] be2net 0000:db:00.0: enabled 4 MSI-x vector(s) for NIC
[ 50.896000] systemd: 1008 callbacks suppressed
^^^^

[ 50.896000] systemd[1]: Started Show Plymouth Boot Screen.
[ 50.896000] systemd[1]: Got SIGCHLD for process 1192 (swapon)
[ 50.896000] systemd[1]: Child 1192 died (code=exited, status=0/SUCCESS)
[ 50.896000] systemd[1]: Child 1192 belongs to dev-disk-by\x2duuid-45671aef\x2dcef3\x2d4fcd\x2d9087\x2d7d4f3f81aa70.swap
[ 50.896000] systemd[1]: dev-disk-by\x2duuid-45671aef\x2dcef3\x2d4fcd\x2d9087\x2d7d4f3f81aa70.swap swap process exited, code=exited status=0
[ 50.896000] systemd[1]: dev-disk-by\x2duuid-45671aef\x2dcef3\x2d4fcd\x2d9087\x2d7d4f3f81aa70.swap changed activating -> active
[ 50.896000] systemd[1]: Job dev-disk-by\x2duuid-45671aef\x2dcef3\x2d4fcd\x2d9087\x2d7d4f3f81aa70.swap/start finished, result=done

...

[ 57.988000] scsi2 : Emulex 10Gbe open-iscsi Initiator Driver
[ 63.028000] be2iscsi 0000:db:00.3: irq 117 for MSI/MSI-X
[ 63.044000] be2iscsi 0000:db:00.3: irq 118 for MSI/MSI-X
[ 63.064000] be2iscsi 0000:db:00.3: irq 119 for MSI/MSI-X
[ 63.080000] be2iscsi 0000:db:00.3: irq 120 for MSI/MSI-X
[ 63.100000] be2iscsi 0000:db:00.3: irq 121 for MSI/MSI-X
[ 63.116000] be2iscsi 0000:db:00.3: irq 122 for MSI/MSI-X
[ 63.132000] be2iscsi 0000:db:00.3: irq 123 for MSI/MSI-X
[ 63.152000] be2iscsi 0000:db:00.3: irq 124 for MSI/MSI-X
[ 63.572000] scsi host2: BC_373 : Link Down on Port 1
[ 63.588000] scsi host2: BM_4336 : No boot session
[ 63.656000] systemd: 11828 callbacks suppressed
^^^^^

We luvz to talk a lot of crap, don't we.

[ 63.672000] systemd[1]: Received SIGCHLD from PID 833 (udevadm).
[ 63.692000] systemd[1]: Got SIGCHLD for process 833 (udevadm)
[ 63.712000] systemd[1]: Child 833 died (code=exited, status=0/SUCCESS)
[ 63.732000] systemd[1]: Child 833 belongs to systemd-udev-settle.service
[ 63.756000] systemd[1]: systemd-udev-settle.service: main process exited, code=exited, status=0/SUCCESS
[ 63.788000] systemd[1]: systemd-udev-settle.service changed start -> exited
[ 63.812000] systemd[1]: Job systemd-udev-settle.service/start finished, result=done
[ 63.836000] systemd[1]: Started udev Wait for Complete Device Initialization.

and so on until we get to the boot prompt:

[ 186.828000] systemd[3512]: Executing: /etc/postfix/system/wait_qmgr 60
[ 186.856000] systemd[3514]: Executing: /etc/postfix/system/cond_slp register
[ 186.892000] systemd[3524]: Executing: /usr/sbin/cron -n
[ 186.892000] systemd[3525]: Executing: /usr/lib/systemd/systemd-update-utmp runlevel
[ 186.896000] systemd[3418]: Executing: /etc/init.d/after.local
[ 186.956000] systemd[3416]: Execung: /sbin/agetty --noclear tty1
[ 186.956000] systemd[3415]: Executing: /sbin/agetty --keep-baud ttyS0 115200,38400,9600
^M

Welcome to SUSE Linux Enterprise Server 12 Beta1 (x86_64) - Kernel 3.12.16-boris-00441-g60dc93e99a75-dirty (ttyS0).

...

Then it keeps spitting out crap off and on but it is much more
manageable. As it should be.

So thanks for that fix:

Acked-and-tested-by: Borislav Petkov <bp@suse.de>

I'll pick it up for SLE12 once it sees a bit more upstream time.

--
Regards/Gruss,
Boris.

Sent from a fat crate under my desk. Formatting is fine.
--