On Sat, Feb 4, 2012 at 12:04 AM, Siddhesh Poyarekar <siddhesh.poyarekar@xxxxxxxxx> wrote: > On Fri, Feb 3, 2012 at 1:31 PM, KOSAKI Motohiro > <kosaki.motohiro@xxxxxxxxx> wrote: >> The fact is, now process stack and pthread stack clearly behave >> different dance. libc don't expect pthread stack grow automatically. >> So, your patch will break userland. Just only change display thing. <snip> > I have also dropped an email on the libc-alpha list here to solicit > comments from libc maintainers on this: > > http://sourceware.org/ml/libc-alpha/2012-02/msg00036.html > Kosaki-san, your suggestion of adding an extra flag seems like the right way to go about this based on the discussion on libc-alpha, specifically, your point about pthread_getattr_np() -- it may not be a standard, but it's a breakage anyway. However, looking at the vm_flags options in mm.h, it looks like the entire 32-bit space has been exhausted for the flag value. The vm_flags is an unsigned long, so it ought to take 8 bytes on a 64-bit system, but 32-bit systems will be left behind. So there are two options for this: 1) make vm_flags 64-bit for all arches. This will cause ABI breakage on 32-bit systems, so any external drivers will have to be rebuilt 2) Implement this patch for 64-bit only by defining the new flag only for 64-bit. 32-bit systems behave as is Which of these would be better? I prefer the latter because it looks like the path of least breakage. -- Siddhesh Poyarekar http://siddhesh.in -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
