From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f175.google.com (mail-ie0-f175.google.com [209.85.223.175]) by kanga.kvack.org (Postfix) with ESMTP id 8F26B6B0038 for ; Sun, 22 Mar 2015 15:47:09 -0400 (EDT) Received: by iedm5 with SMTP id m5so22422909ied.3 for ; Sun, 22 Mar 2015 12:47:09 -0700 (PDT) Received: from mail-ie0-x232.google.com (mail-ie0-x232.google.com. [2607:f8b0:4001:c03::232]) by mx.google.com with ESMTPS id k4si4183893igu.6.2015.03.22.12.47.09 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 22 Mar 2015 12:47:09 -0700 (PDT) Received: by iedfl3 with SMTP id fl3so26266437ied.1 for ; Sun, 22 Mar 2015 12:47:09 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20150322.133603.471287558426791155.davem@davemloft.net> References: <550DAE23.7030000@oracle.com> <20150322.133603.471287558426791155.davem@davemloft.net> Date: Sun, 22 Mar 2015 12:47:08 -0700 Message-ID: Subject: Re: 4.0.0-rc4: panic in free_block From: Linus Torvalds Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org List-ID: To: David Miller Cc: David Ahern , sparclinux@vger.kernel.org, linux-mm , Linux Kernel Mailing List On Sun, Mar 22, 2015 at 10:36 AM, David Miller wrote: > > And they end up using that byte-at-a-time code, since SLAB and SLUB > do mmemove() calls of the form: > > memmove(X + N, X, LEN); Actually, the common case in slab is overlapping but of the form memmove(p, p+x, len); which goes to memcpy. It's basically re-compacting the array at the beginning. Which was why I was asking how sure you are that memcpy *always* copies from low to high. 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? Linus -- 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