Messages in this thread | | | Date | Thu, 21 Feb 2013 17:46:16 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re: [PATCH] nohz: Make tick_nohz_irq_exit() irq safe |
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On Thu, 21 Feb 2013, Frederic Weisbecker wrote: > 2013/2/21 Thomas Gleixner <tglx@linutronix.de>: > > On Wed, 20 Feb 2013, Frederic Weisbecker wrote: > >> 2013/2/20 Thomas Gleixner <tglx@linutronix.de>: > >> > That's not a fix. That's an hack. > >> > >> I know it looks that way. That's because it's a pure regression fix, > >> minimal for backportability. > >> > >> I'm distinguishing two different things here: the fact that some archs > >> can call irq_exit() with interrupts enabled which is a global design > >> problem, and the fact that tick_nohz_irq_exit() was safe against that > >> until 3.2 when I broke it with a commit of mine. > >> > >> My goal was basically to restore that protection in a minimal commit > >> such that we can backport the regression fix, then deal with > >> __ARCH_IRQ_EXIT_IRQS_DISABLED afterward, since it requires some more > >> invasive changes. > >> > >> >> A saner long term solution will be to remove > >> >> __ARCH_IRQ_EXIT_IRQS_DISABLED. > >> > > >> > We really want to enforce that interrupt disabled condition for > >> > calling irq_exit(). So why make this exclusive to tick_nohz_irq_exit()? > >> > >> I need a fix that I can backport. Is the below fine with a stable tag? > >> It looks a bit too invasive for the single regression involved. > > > > I think that's fine as it's obviously correct and not diluting the > > real underlying issue of the __ARCH_IRQ_EXIT_IRQS_DISABLED insanity. > > Ok fine. Do you plan to commit your proposed change then?
Second thoughts. I probably go for your minimal fix for stable and then push my version on top of it to Linus only.
Thanks,
tglx
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