From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f50.google.com (mail-oi0-f50.google.com [209.85.218.50]) by kanga.kvack.org (Postfix) with ESMTP id 7EF426B0036 for ; Wed, 30 Jul 2014 06:37:23 -0400 (EDT) Received: by mail-oi0-f50.google.com with SMTP id a141so708234oig.37 for ; Wed, 30 Jul 2014 03:37:23 -0700 (PDT) Received: from g2t2353.austin.hp.com (g2t2353.austin.hp.com. [15.217.128.52]) by mx.google.com with ESMTPS id yc9si4130757obc.71.2014.07.30.03.37.22 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Wed, 30 Jul 2014 03:37:22 -0700 (PDT) Message-ID: <1406716641.9336.17.camel@buesod1.americas.hpqcorp.net> Subject: Re: [PATCH] mm: BUG when __kmap_atomic_idx crosses boundary From: Davidlohr Bueso Date: Wed, 30 Jul 2014 03:37:21 -0700 In-Reply-To: <20140730020615.2f943cf7.akpm@linux-foundation.org> References: <1406710355-4360-1-git-send-email-cpandya@codeaurora.org> <20140730020615.2f943cf7.akpm@linux-foundation.org> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Chintan Pandya , linux-kernel@vger.kernel.org, linux-mm@kvack.org On Wed, 2014-07-30 at 02:06 -0700, Andrew Morton wrote: > On Wed, 30 Jul 2014 14:22:35 +0530 Chintan Pandya wrote: > > > __kmap_atomic_idx >= KM_TYPE_NR or < ZERO is a bug. > > Report it even if CONFIG_DEBUG_HIGHMEM is not enabled. > > That saves much debugging efforts. > > Please take considerably more care when preparing patch changelogs. > > kmap_atomic() is a very commonly called function so we'll need much > more detail than this to justify adding overhead to it. > > I don't think CONFIG_DEBUG_HIGHMEM really needs to exist. We could do > s/CONFIG_DEBUG_HIGHMEM/CONFIG_DEBUG_VM/g and perhaps your secret bug > whatever it was would have been found more easily. Agreed, it would be nice to fold DEBUG_HIGHMEM into DEBUG_VM. However you'd still need some kind of intermediate option as DEBUG_VM must still exist if !HIGHMEM. Thanks, Davidlohr -- 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