[Xenomai] Merging v4.4.108 into I-Pipe, issue with switch_mm on x86

Jan Kiszka jan.kiszka at siemens.com
Thu Feb 8 09:22:18 CET 2018

On 2018-02-08 09:12, Sudler, Simon (PD PA CI R&D 3) wrote:
> Hi Guys,
> I was just about to merging the v4.4.108 tag into the I-Pipe branch when I fall over these 4
> commits from Andy Lutomirski:
> git log --oneline dfe513a4e8ddde75ffc6abd3f139c5d65bf925d7..4ead44fd2525ed97e5362a806d312a0e3b0ea445
> 4ead44fd2525 x86/mm, sched/core: Turn off IRQs in switch_mm()
> 70a39c7fd167 x86/mm, sched/core: Uninline switch_mm()
> 83cc4b50e3a9 x86/mm: Build arch/x86/mm/tlb.c even on !SMP
> 425f13a36652 sched/core: Add switch_mm_irqs_off() and use it in the scheduler
> He introduces a switch_mm_irqs_off function and turns IRQs of inside the switch_mm function. In
> the switch_mm case local_irq_save/restore is to handle the interrupt flags.
> In the I-Pipe case, the switch_mm functions was renamed to __switch_mm which then handels the
> irq flags with hard_cond_local_irq_save/restore.
> So my question is: Is this double saving and restoring of the flags useful in the I-Pipe case? Maybe
> the the hard_cond_local_irq_save/restore can be moved to the local_irq_save/restore to have the
> irq flag handling at one place.

Oops, when chatting with you, I totally forgot that I already did a 109
merge last month, just didn't find enough time to test. Now that you are
mentioning this concrete conflict, I started to remember. Please have a
look at
That version /seems/ to work.


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