From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Gardner Date: Wed, 27 Apr 2016 20:06:04 +0000 Subject: Re: Bisected: RED State Exception in 4.5 on E420R Message-Id: <57211BAC.9070902@oracle.com> List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: sparclinux@vger.kernel.org On 04/27/2016 02:01 PM, David Miller wrote: > From: Rob Gardner > Date: Wed, 27 Apr 2016 13:46:46 -0600 > >> On 04/27/2016 01:36 PM, David Miller wrote: >>> From: David Miller >>> Date: Wed, 27 Apr 2016 15:33:55 -0400 (EDT) >>> >>>> Therefore some other aspect of the change is causing problems and I >>>> think that aspect is the size of the new code. >>> Actually, there is a way to prove that this is indeed the bug, Meelis >>> what does the entry for "swapper_tsb" say in your System.map file for >>> a failing kernel? >>> >>> If it is not "0000000000408000", then that shows the bug. >>> >> >> I've run into this situation, and the assembler emits a warning that >> looks like this: >> >> arch/sparc/kernel/head_64.S:869: Warning: .space or .fill with >> negative value, ignored >> >> I've worked around it by moving some of the includes to after the >> ttable include. I think this is ok as long as code doesn't get >> situated too far away for the branch displacement to handle. > Maybe older binutils don't catch this properly. > > On my config here I definitely can see that the size is getting > really close to the limit, and that's without all of the mentioned > features enabled. > > Meanwhile, I'll keep working on the patch I said I'd do which trims > down the size of all of this code. Also, perhaps think about a way to make the assembler emit something fatal instead of a warning when this situation occurs? People tend to ignore warnings. ;) Rob