Bug 730417

Summary: remove '--with smp' kernel spec file option and replace with working '--with up'
Product: [Fedora] Fedora Reporter: Matthew Whitehead <mwhitehe>
Component: kernelAssignee: Kernel Maintainer List <kernel-maint>
Status: CLOSED WONTFIX QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: unspecified    
Version: rawhideCC: aquini, gansalmon, itamar, jonathan, jwboyer, kernel-maint, madhu.chinakonda
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Last Closed: 2011-08-15 18:07:54 UTC Type: ---
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Fix with_up to work none

Description Matthew Whitehead 2011-08-12 20:36:52 UTC 
Description of problem: Presently there is a "--with smp" kernel.spec option for use with rpmbuild. However, all current kernel config files except arm and powerpc32-generic enable the smp option. For most architectures you cannot opt-out of smp using "--with up".

Version-Release number of selected component (if applicable): RHEL > 4


How reproducible: 100%


Steps to Reproduce:
1. Build a kernel using rpmbuild and '--with up'. It will NOT build a uniprocessor kernel because the config files override it.
2.
3.
  
Actual results: SMP kernel.


Expected results: Uniprocessor kernel.


Additional info:
Comment 1 Josh Boyer 2011-08-15 12:04:34 UTC 
An x86 SMP kernel will realize there is only one CPU and patch out various sections of SMP code to act as a UP kernel.  Why do we need to force a UP kernel?
Comment 2 Matthew Whitehead 2011-08-15 12:56:58 UTC 
We need to force a UP kernel on systems that have > 1 core, but you want to test UP behavior. It's not the same as setting MAXCPUS=1.
Comment 3 Josh Boyer 2011-08-15 17:51:14 UTC 
Created attachment 518300 [details]
Fix with_up to work

I'm not sure who "we" is in this context, but something like the attached patch would be needed.  I wouldn't expect Fedora to build this by default at all, but it would make the with_up setting a viable option for those wanting to do that kind of debugging with a local build.
Comment 4 Dave Jones 2011-08-15 18:07:54 UTC 
I'm hesitant to further ugly up the spec & config set with something this niche.
We don't ship UP builds, so this is purely a minority development knob.

Rather than make the rats-nest of config generation even more complicated, I'm closing this WONTFIX.  If you want to do a build with config options we don't ship/support, either make those changes locally, or do a non-rpm based build.