On 11/30, Jiri Kosina wrote: > > On Fri, 29 Nov 2013, Oleg Nesterov wrote: > > > > > Andi, et al. I am going to discuss the things I do not really > > > > understand, probably this can't make any sense, but... > > > > > > I think it's enough to set the dirty bit in the underlying > > > struct page, no need to play games with the PTE. > > > > Ah, sorry for confusion, I guess you misunderstood. > > > > I meant, perhaps sys_text_poke() doesn't the in-kernel text_poke > > machinery altogether? > > > > Can't we invalidate pte (so that any user will stuck in page fault), > > update the page(s), restore the pte and drop the locks? > > Do you think this'd be faster than the int3-based aproach?
No. And more, I simply do not know if it would be slower or faster, and how much. Just I hope that this won't be "much" slower. OTOH, this is obviously more scalable, and this way sys_text_poke() won't block, say, jump_label or kprobes. Not sure this actually matters though. > We have moved from using stop_machine() to int3-based patching exactly > because it's much more lightweight. Oh, I do not think it makes sense to compare stop_machine() with this approach... Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
