Hi Ohmichi-san, Ken'ichi Ohmichi wrote: > Hi, > > This patch enables a kdump if 2nd-kernel is loaded. > (The patch is based on linux-2.6.31-rc2.) > > Now, a kdump is enabled if a kernel parameter "oops=panic" is specified and > 2nd-kernel is loaded. I think that a kdump should be enabled regardless of > "oops=panic" if 2nd-kernel is loaded, because a system administrator loads > 2nd-kernel for enabling a kdump. I think this description is slightly wrong because kdump will be invoked from panic, regardless of the panic_on_oops. Maybe: A kdump on oops is enabled if a kernel parameter "oops=panic" ... ~~~~~~~ > > * Reference > The discussion about this patch > http://lists.infradead.org/pipermail/kexec/2009-July/003417.html I'd like to quote your comment: >> I tried to test a kdump on linux-2.6.31-rc1 *without* a kernel parameter >> "oops=panic" by `echo c > /proc/sysrq-trigger`, but a kdump did not work >> because a kdump, which is occurred by `echo c > /proc/sysrq-trigger`, has >> been changed to a NULL pointer error instead of calling crash_kexec() >> since linux-2.6.31-rc1. So the real problem is that kdump is not triggered by the NULL pointer oops if !panic_on_oops, isn't it? It seems that you should report this trouble of sysrq-c as a regression. > > > Thanks > Ken'ichi Ohmichi > > Signed-off-by: Ken'ichi Ohmichi <oomichi at mxs.nes.nec.co.jp> > Acked-by: Simon Horman <horms at verge.net.au> > --- > --- a/kernel/kexec.c 2009-07-08 12:30:26.000000000 +0900 > +++ b/kernel/kexec.c 2009-07-08 12:38:08.000000000 +0900 > @@ -57,6 +57,8 @@ struct resource crashk_res = { > > int kexec_should_crash(struct task_struct *p) > { > + if (kexec_crash_image) > + return 1; > if (in_interrupt() || !p->pid || is_global_init(p) || panic_on_oops) > return 1; > return 0; I think kexec cannot crash if there is no image, right? Then: if (kexec_crash_image) return 1; return 0; or return (kexec_crash_image) ? 1 : 0; or since crash_kexec() is nop if !kexec_crash_image, replace all: if (kexec_should_crash(p)) crash_kexec(reg); at everywhere in kernel to a simple line: crash_kexec(reg); and remove kexec_should_crash() completely would be better fix. Thanks, H.Seto