From mboxrd@z Thu Jan 1 00:00:00 1970 From: Olaf Hering Subject: Re: [PATCH] xen: increase static dmesg buffer to 64K Date: Mon, 18 Jul 2011 10:45:12 +0200 Message-ID: <20110718084512.GA23061@aepfle.de> References: <20110718081628.GA22448@aepfle.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Keir Fraser Cc: xen-devel@lists.xensource.com, Jan Beulich List-Id: xen-devel@lists.xenproject.org On Mon, Jul 18, Keir Fraser wrote: > On 18/07/2011 09:16, "Olaf Hering" 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