Hello Eric and Vivek, Do you have any comments? (2015/07/24 10:16), Hidehiro Kawai wrote: > This is a bugfix patch for crash_kexec_post_notifiers boot option > which allows users to call panic notifiers and kmsg dumpers before > kdump. > > This fixes one of the problems reported by Daniel Walker > (https://lkml.org/lkml/2015/6/24/44). > > Problem 1: > If crash_kexec_post_notifiers boot option is specified, some > shutting down process which assume other cpus are still alive > don't work properly. > > Problem 2 (addressed by this patch): > If crash_kexec_post_notifiers boot option is specified, register > information of other cpus are not saved to crash dumps. > > Following Vivek's opinion, this patch replaces smp_send_stop() > in panic() with suitable version for crash_kexec which saves > cpu states and other things like cleaning up VMX/SVM. Since this > needs architecture specific implementation and it's not so trivial, > this version only support for x86. So the problem 1, known to > happen on MIPS/OCTEON, is not addressed now. > > To keep the modification impact low, this patch doesn't change > the logic basically if crash_kexec_post_notifiers is not specified. > > Please note that crash_kexec() can be called directly without > entering panic(). Stopping other cpus functionality is still > needed in crash_kexec(). > > Changes in V2: > - Replace smp_send_stop() call with crash_kexec version which > saves cpu states and does cleanups instead of changing execution > flow > - Drop a fix for Problem 1 > - Drop other patches because they aren't needed anymore > > V1: https://lkml.org/lkml/2015/7/10/316 > > --- > > Hidehiro Kawai (1): > panic/x86: Replace smp_send_stop() with crash_kexec version > > > arch/x86/kernel/crash.c | 16 +++++++++++----- > kernel/panic.c | 29 +++++++++++++++++++++++------ > 2 files changed, 34 insertions(+), 11 deletions(-) > > -- Hidehiro Kawai Hitachi, Ltd. Research & Development Group
