Thread (175 messages) 175 messages, 28 authors, 2022-05-24

Re: [PATCH 20/30] panic: Add the panic informational notifier list

From: Petr Mladek <pmladek@suse.com>
Date: 2022-05-16 14:11:40
Also in: kexec, linux-alpha, linux-edac, linux-hyperv, linux-leds, linux-mips, linux-remoteproc, linux-s390, linux-tegra, linux-um, linuxppc-dev, lkml, netdev, rcu, sparclinux, xen-devel

On Wed 2022-04-27 19:49:14, Guilherme G. Piccoli wrote:
The goal of this new panic notifier is to allow its users to
register callbacks to run earlier in the panic path than they
currently do. This aims at informational mechanisms, like dumping
kernel offsets and showing device error data (in case it's simple
registers reading, for example) as well as mechanisms to disable
log flooding (like hung_task detector / RCU warnings) and the
tracing dump_on_oops (when enabled).

Any (non-invasive) information that should be provided before
kmsg_dump() as well as log flooding preventing code should fit
here, as long it offers relatively low risk for kdump.

For now, the patch is almost a no-op, although it changes a bit
the ordering in which some panic notifiers are executed - specially
affected by this are the notifiers responsible for disabling the
hung_task detector / RCU warnings, which now run first. In a
subsequent patch, the panic path will be refactored, then the
panic informational notifiers will effectively run earlier,
before ksmg_dump() (and usually before kdump as well).

We also defer documenting it all properly in the subsequent
refactor patch. Finally, while at it, we removed some useless
header inclusions too.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
All notifiers moved in this patch seems to fit well the "info"
notifier list. The patch looks good from this POV.

I still have to review the rest of the patches to see if it
is complete.

Best Regards,
Petr
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help