On Fri, Jun 27, 2014 at 04:59:14PM -0700, Andrew Morton wrote: > On Thu, 26 Jun 2014 16:32:15 -0700 "Luis R. Rodriguez" <mcg...@suse.com> > wrote: > > > On Thu, Jun 26, 2014 at 4:20 PM, Andrew Morton > > <a...@linux-foundation.org> wrote: > > > On Fri, 27 Jun 2014 01:16:30 +0200 "Luis R. Rodriguez" <mcg...@suse.com> > > > wrote: > > > > > >> > > Another note -- since this option depends on SMP and !BASE_SMALL > > >> > > technically > > >> > > num_possible_cpus() won't ever return something smaller than or > > >> > > equal to 1 > > >> > > but because of the default values chosen the -1 on the compuation > > >> > > does affect > > >> > > whether or not this will trigger on > 64 CPUs or >= 64 CPUs, keeping > > >> > > the > > >> > > -1 means we require > 64 CPUs. > > >> > > > >> > hm, that sounds like more complexity. > > >> > > > >> > > This all can be changed however we like but the language and > > >> > > explained logic > > >> > > would just need to be changed. > > >> > > > >> > Let's start out simple. What's wrong with doing > > >> > > > >> > log buf len = max(__LOG_BUF_LEN, nr_possible_cpus * per-cpu log > > >> > buf len) > > >> > > >> Sure, you already took in the patch series though so how would you like > > >> to > > >> handle a respin, you just drop the last patch and we respin it? > > > > > > A fresh patch would suit. That's if you think it is a reasonable > > > approach - you've thought about this stuff more than I have! > > > > The way its implemented now makes more technical sense, in short it > > assumes the first boot (and CPU) gets the full default kernel ring > > buffer size, the extra size is for the gibberish that each extra CPU > > is expected to spew out in the worst case. What you propose makes the > > explanation simpler and easier to understand but sends the wrong > > message about exactly how the growth of the kernel ring buffer is > > expected scale with the addition of more CPUs. > > OK, it's finally starting to sink in. The model for the kernel-wide > printk output is "a great pile of CPU-independent stuff plus a certain > amount of per-cpu stuff". And the code at present attempts to follow > that model. Yes?
Yup, exactly. > I'm rather internet-challenged at present - please let me take another look at > the patch on Monday. OK! Luis -- 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/
