From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:50294) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UDQjb-0006c5-H9 for qemu-devel@nongnu.org; Wed, 06 Mar 2013 21:39:08 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UDQjZ-00031g-RY for qemu-devel@nongnu.org; Wed, 06 Mar 2013 21:39:07 -0500 Received: from mail-oa0-f49.google.com ([209.85.219.49]:59383) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UDQjZ-00031X-N6 for qemu-devel@nongnu.org; Wed, 06 Mar 2013 21:39:05 -0500 Received: by mail-oa0-f49.google.com with SMTP id j6so13369981oag.8 for ; Wed, 06 Mar 2013 18:39:04 -0800 (PST) From: Anthony Liguori In-Reply-To: References: <51358208.1020409@msgid.tls.msk.ru> Date: Wed, 06 Mar 2013 20:38:53 -0600 Message-ID: <87r4jsx7b6.fsf@codemonkey.ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Subject: Re: [Qemu-devel] default guest RAM size? List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Maydell , Michael Tokarev Cc: qemu-devel Peter Maydell writes: > On 5 March 2013 13:26, Michael Tokarev wrote: >> For many years, qemu defaults to 128Mb of guest RAM size. >> Today, this is just too small, and many OSes fails to boot >> with this size, more, they fail to produce any reasonable >> messages either (eg, windows7 just crashes at startup). > > If you make the default bigger then some boards will crash > or behave weirdly because they try to map more RAM in than > will fit into the space for RAM in their address maps. > >> Some distributions (eg ubuntu) had a local patch to increase >> this value, for years. >> >> Maybe it's time to increase the default RAM size a bit? >> Make it arch-specific if needs to be ? > > I tried two years ago to get a 'default RAM size' parameter I don't see that in this series. It's a maximum RAM size. Anyway, there's no problem changing the default ram size (and making it per-board). The only requirement is that -M pc-1.4 and below continues to expose 128MB as the default. It's not worth bike shedding over what the default should be for pc targets. 256 or 512 would be equally good defaults and either would be acceptable. Regards, Anthony Liguori > added to the QEMUMachine struct, but the patchseries got shot > down because it didn't attempt to address NUMA / simulate > the fact you can only add RAM one DIMM at a time / etc... > > http://lists.gnu.org/archive/html/qemu-devel/2011-03/msg02907.html > > -- PMM