Messages in this thread | | | Date | Sat, 14 Feb 2009 15:31:24 -0800 | From | Andrew Morton <> | Subject | Re: [RFC v13][PATCH 00/14] Kernel based checkpoint/restart |
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On Sun, 15 Feb 2009 00:08:02 +0100 Ingo Molnar <mingo@elte.hu> wrote:
> > * Andrew Morton <akpm@linux-foundation.org> wrote: > > > Similar to the way in which perfectly correct and normal kernel > > sometimes has to be changed because it unexpectedly upsets the -rt > > patch. > > Actually, regarding -rt, we try to keep that in two buckets: > > 1) Normal kernel code works but is unclean or structured less > than ideal. In this case we restructure the mainline code, > but that change stands on its own four legs, without any > -rt considerations. > > 2) Normal kernel code that is clean - i.e. a change that only > matters to -rt. In this case we dont touch the mainline code, > nor do we bother mainline. > > Do you know any specific example that falls outside of those categories? >
It happens fairly regularly. Problems with irqs-off regions, problems with preempt_disable() regions (came up just yesterday with a patch from Jeremy).
Plus some convert-to-sleeping-lock conversions over the years which weren't obviously needed in mainline. Or which at least had -rt motivations. But that's different.
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