On 12/11, Nicolas Pitre wrote: > On Fri, 11 Dec 2015, Arnd Bergmann wrote: > > > On Friday 11 December 2015 12:22:20 Nicolas Pitre wrote: > > > Subject: [PATCH] ARM: Runtime patch udiv/sdiv instructions into __aeabi_{u}idiv() > > > > > Thanks. > > > Before you put it in the patch tracker, I think it would be good to > > give Stephen a chance to comment as well, since he did a lot of > > work upfront and this obsoletes his original patch series. > > Given he'll get back from vacation only after the new year, I'll put the > patch in the tracker now so it can go in before the next merge window. > > Stephen's series could still be relevant by extending what is done here, > and it requires what this patch is doing anyway for those call sites > that can't be substituted by a div instruction (like conditional > branches, tail call optimizations, etc.) > I'm back from vacation now. Where have we left off on this topic? I can update the patches to be based on this patch here and handle the conditional branches and tail call optimization cases by adding some safety checks like we have for the ftrace branch patching. But I'd rather not do that work unless we all agree that it's worthwhile pursuing it. Is there still any concern about the benefit of patching each call site vs. patching the functions? The micro benchmark seems to show some theoretical improvement on cortex-a7 and I can run it on Scorpion and Krait processors to look for any potential benefits there, but I'm not sure of any good kernel benchmark for this. If it will be rejected due to complexity vs. benefit arguments I'd rather work on something else. -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html