From mboxrd@z Thu Jan 1 00:00:00 1970 From: Simon Horman Date: Tue, 29 Jul 2008 22:40:41 +0000 Subject: Re: [patch 1/3] kdump: use is_kdump_kernel() in sba_init() Message-Id: <20080729224039.GE6370@verge.net.au> List-Id: References: <20080729081235.293361145@vergenet.net> <20080729081629.356523305@vergenet.net> <20080729145156.GO25975@redhat.com> In-Reply-To: <20080729145156.GO25975@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Vivek Goyal Cc: kexec@lists.infradead.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org On Tue, Jul 29, 2008 at 10:51:56AM -0400, Vivek Goyal wrote: > On Tue, Jul 29, 2008 at 06:12:36PM +1000, Simon Horman wrote: > > After recent patches* is_kdump_kernel() should return 1 in the > > case where code is executing in a crashkernel and 0 otherwise. > > It is save to use outside of CONFIG_KDUMP. > > > > * http://lkml.org/lkml/2008/7/28/445 > > > > Hi Simon, > > is_kdump_kernel() returns 1 when both the following conditions are true. > > - CONFIG_CRASH_DUMP is enabled > - And kernel is booting after a panic. > > If any of the above condition is not true, it returns 0. > > So for the cases where, CONFIG_CRASH_DUMP=n and kernel is booting after > panic, is_kdump_kernel() will still return 0. > > This essentially means that any kernel which is booting after a panic, > but does not have CONFIG_CRASH_DUMP enabled, will not take special actions > required for booting that kernel. Until, somebody can come up with another > usage of booting a kernel after a panic (apart from crash dump), I think > this is good enough an assumption. > > So your changes will work. I just wanted to clarify the semantics more > explicitly. Hi Vivek, sorry if my explanation was confused. The scheme that you describe above is what I am working with too. -- Horms