[PATCH] Documentation: Improve crash_kexec_post_notifiers description

From: Guilherme G. Piccoli
Date: Fri Aug 30 2024 - 10:05:11 EST


Be more clear about the downsides, the upsides (yes, there are some!)
and about code that unconditionally sets that.

Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxx>
---
Documentation/admin-guide/kernel-parameters.txt | 16 ++++++++++------
1 file changed, 10 insertions(+), 6 deletions(-)

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index efc52ddc6864..cb25dc5cbe9a 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -913,12 +913,16 @@
the parameter has no effect.

crash_kexec_post_notifiers
- Run kdump after running panic-notifiers and dumping
- kmsg. This only for the users who doubt kdump always
- succeeds in any situation.
- Note that this also increases risks of kdump failure,
- because some panic notifiers can make the crashed
- kernel more unstable.
+ Only jump to kdump kernel after running the panic
+ notifiers and dumping kmsg. This option increases the
+ risks of a kdump failure, since some panic notifiers
+ can make the crashed kernel more unstable. As a bright
+ side, it might allow to collect more data on dmesg like
+ stack traces from other CPUs or extra data dumped by
+ panic_print. This is usually only for users who doubt
+ kdump will succeed every time. Notice that some code
+ enables this option unconditionally, like Hyper-V,
+ PowerPC (fadump) and AMD SEV.

crashkernel=size[KMG][@offset[KMG]]
[KNL,EARLY] Using kexec, Linux can switch to a 'crash kernel'
--
2.46.0