Re: [PATCH] xen: increase static dmesg buffer to 64K

[Olaf Hering <olaf@aepfle.de>]

On Mon, Jul 18, Keir Fraser wrote:

> On 18/07/2011 09:16, "Olaf Hering" <olaf@aepfle.de> wrote:
> > I think conring_size= should be evaluated very early. Is there a way to
> > allocate a range of mfns very early which can then be used for the dmesg
> > buffer?
> 
> Are you actually losing messages because you can't allocate the larger
> console ring early enough? It seems a bit unlikely, but possible I suppose.

Yes, I was booting with conring_size=, but the bulk of messages were
already printed at that point. My 80 cpu testbox had 24K in dmesg buffer
with my patch.

> Anyhow, the normal memory allocator is available plenty early enough. You'd
> just need to do the allocation earlier than console_init_postirq(). Sometime
> soon after the call to end_boot_allocator() would work nicely.

I will put that on my TODO list, and look at your and Jans suggestion to
move the dmesg buffer allocation earlier.

Olaf