On Tue, 2005-09-27 at 13:38 -0600, dann frazier wrote: > On Tue, 2005-09-27 at 11:00 -0700, Christoph Lameter wrote: > > On Tue, 27 Sep 2005, Sven Luther wrote: > > > > > Do you mean that kexec doesn't work in SMP situations ? I am not sure > > > what you > > > mean about test situations and the SMP kernel should work just well in > > > virtualized environments, but i have some trouble equating ia64 machines > > > with > > > low memory situations :) > > > > The new kernel started with kexec for debugging purposes may need to be > > simple and small. AFAIK the amount of memory for the second kernel is > > limited. Virtualization of SMP environments is pretty complex. In > > many situations its just nice to have a UP kernel around. > > Khalid: I know you've been hacking on kexec a lot lately - can you > comment on the kexec case? Do you know if such a limitation exists, and > what it is?
I have not come across any such limitation. I kexec a full blown SMP kernel with lots of things built-in a few times every day. The only issue I can think of is that currently running kernel has to load a to be kexec'd kernel in memory and it kmalloc's memory to hold this image. If kernel does not have enough memory to load a new kernel, then you could see a limitation on how big a kernel can be kexec'd, but that situation is no different from running the system out of memory and not being able to kmalloc memory for any other reason as well. -- Khalid > > Christoph: What other cases might you think of where booting an SMP > kernel with maxcpus=1 is not sufficient? > > The only concern I had prior to starting this thread is the performance > overhead; I'm interested in any benchmarks that might be able to > demonstrate a difference here. > > -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
