From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f182.google.com (mail-pd0-f182.google.com [209.85.192.182]) by kanga.kvack.org (Postfix) with ESMTP id 7061A6B0038 for ; Sun, 22 Mar 2015 18:23:17 -0400 (EDT) Received: by pdbcz9 with SMTP id cz9so167320391pdb.3 for ; Sun, 22 Mar 2015 15:23:17 -0700 (PDT) Received: from shards.monkeyblade.net (shards.monkeyblade.net. [2001:4f8:3:36:211:85ff:fe63:a549]) by mx.google.com with ESMTP id rp11si19130037pab.75.2015.03.22.15.23.16 for ; Sun, 22 Mar 2015 15:23:16 -0700 (PDT) Date: Sun, 22 Mar 2015 18:23:11 -0400 (EDT) Message-Id: <20150322.182311.109269221031797359.davem@davemloft.net> Subject: Re: 4.0.0-rc4: panic in free_block From: David Miller In-Reply-To: References: <20150322.133603.471287558426791155.davem@davemloft.net> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: torvalds@linux-foundation.org Cc: david.ahern@oracle.com, sparclinux@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org From: Linus Torvalds Date: Sun, 22 Mar 2015 12:47:08 -0700 > Which was why I was asking how sure you are that memcpy *always* > copies from low to high. Yeah I'm pretty sure. > I don't even know which version of memcpy ends up being used on M7. > Some of them do things like use VIS. I can follow some regular sparc > asm, there's no way I'm even *looking* at that. Is it really ok to use > VIS registers in random contexts? Yes, using VIS how we do is alright, and in fact I did an audit of this about 1 year ago. This is another one of those "if this is wrong, so much stuff would break" The only thing funny some of these routines do is fetch 2 64-byte blocks of data ahead in the inner loops, but that should be fine right? On the M7 we'll use the Niagara-4 memcpy. Hmmm... I'll run this silly sparc kernel memmove through the glibc testsuite and see if it barfs. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org