On 10/29/13 at 10:36am, Dave Young wrote: > On 10/29/13 at 11:04am, Simon Horman wrote: > > On Mon, Oct 28, 2013 at 12:10:40PM -0400, Vivek Goyal wrote: > > > On Mon, Oct 28, 2013 at 10:51:19AM +0000, Matthew Garrett wrote: > > > > On Mon, Oct 28, 2013 at 06:45:32PM +0800, Dave Young wrote: > > > > > On 10/28/13 at 10:39am, Matthew Garrett wrote: > > > > > > On Mon, Oct 28, 2013 at 06:34:12PM +0800, Dave Young wrote: > > > > > > > On 10/28/13 at 10:12am, Matthew Garrett wrote: > > > > > > > > Right, but previously acpi_rsdp was passed automatically and now it > > > > > > > > won't be? > > > > > > > > > > > > > > Yes, it was. I'm removing them in kexec-tools patches for efi runtime support. > > > > > > > > > > > > If I upgrade kexec-tools and try to launch an old kernel, I now need to > > > > > > add an extra parameter? > > > > > > > > > > Yes, it should work by passing the acpi_rsdp= via --append > > > > > > > > Yes, that's my point. You're breaking old configurations by requiring > > > > the user to pass an additional argument. > > > > > > Yes this is a problem. Of course solution is easy by always passing > > > acpi_rsdp on command line. But in long term this is a problem. In the > > > sense, I am not sure how to cleanup the kexec-tools code as things improve. > > > Now we will support the EFI properly and still pass acpi_rsdp always in > > > an effort to matain backward compatibility. > > > > > > For a very long time kexec-tools were not automatically appending > > > acpi_rsdp and user were supposed to add it on command line. We were > > > carrying this change in kdump scripts and pushed this change into > > > kexec-tools. In hindsight, it looks like that hardcoding parameters > > > in kexec-tools is a bad idea. It is hard to get rid of them in future. > > > > I tend to agree. However, if the parameters end up being hard coded > > elsewhere, for example in widely used wrapper scripts, then I think that > > the same problem still exists. Just outside of kexec-tools itself. > > Kernel has a rule of not breaking userspace, does kexec-tools also have the > policy? Maybe user or distribution carry that will be slight better so upstream > kexec code will be cleaner.. Forgot what I said above about the policy, they are different things. I just replied mjg that even carry this acpi_rsdp, old kernel can not be used because there's efi info in setup_header.
