On 08/30/24 at 03:21pm, Guilherme G. Piccoli wrote: > Be more clear about the downsides, the upsides (yes, there are some!) > and about code that unconditionally sets that. > > Reviewed-by: Stephen Brennan <stephen.s.brennan@xxxxxxxxxx> > Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxx> > > --- > > V2: Some wording improvements from Stephen, thanks! > Also added his review tag. > > V1 link: https://lore.kernel.org/r/20240830140401.458542-1-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..351730108c58 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. In the > + configurations where kdump may not be reliable, > + running the panic notifiers can allow collecting more > + data on dmesg, like stack traces from other CPUS or > + extra data dumped by panic_print. Notice that some > + code enables this option unconditionally, like > + Hyper-V, PowerPC (fadump) and AMD SEV. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I know Hyper-V enable panic-notifiers by default, but don't remember how PowerPC and AMD SEC behave in this aspect. While at it, can you add a little more words to state them in log so that people can learn it? Thanks. > > crashkernel=size[KMG][@offset[KMG]] > [KNL,EARLY] Using kexec, Linux can switch to a 'crash kernel' > -- > 2.46.0 >
