Messages in this thread | | | From | Borislav Petkov <> | Subject | [PATCH -v3 0/2] printk.devkmsg: Ratelimit it by default | Date | Mon, 4 Jul 2016 16:24:50 +0200 |
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From: Borislav Petkov <bp@suse.de>
Hi all,
here's v3 integrating Ingo's comments. The thing is called printk.devkmsg= or printk_devkmsg now, depending on cmdline option or sysctl.
Changelog: ----------
v2:
here's v2 with the requested sysctl option kernel.printk_kmsg and locking of the setting when printk.kmsg= is supplied on the command line.
Patch 1 is unchanged.
Patch 2 has grown the sysctl addition.
v1:
Rostedt is busy so I took Linus' old patch and Steven's last v2 and split and extended them with the comments people had on the last thread:
https://lkml.kernel.org/r/20160425145606.598329f2@gandalf.local.home
I hope, at least.
So it is ratelimiting by default, with "on" and "off" cmdline options. I called the option somewhat a bit shorter too: "printk.kmsg"
The current use cases of this and of which I'm aware are:
* debug the kernel and thus shut up all interfering input from userspace, i.e. boot with "printk.kmsg=off"
* debug userspace (and by that I mean systemd) by booting with "printk.kmsg=on" so that the ratelimiting is disabled and the kernel log gets all the spew.
Thoughts?
Thanks.
Borislav Petkov (2): ratelimit: Extend to print suppressed messages on release printk: Add kernel parameter to control writes to /dev/kmsg
Documentation/kernel-parameters.txt | 6 +++ Documentation/sysctl/kernel.txt | 14 +++++++ include/linux/printk.h | 7 ++++ include/linux/ratelimit.h | 36 +++++++++++++--- kernel/printk/printk.c | 83 +++++++++++++++++++++++++++++++++---- kernel/sysctl.c | 9 ++++ lib/ratelimit.c | 6 ++- 7 files changed, 146 insertions(+), 15 deletions(-)
-- 2.7.3
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