From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753226Ab0CZUkQ (ORCPT ); Fri, 26 Mar 2010 16:40:16 -0400 Received: from hera.kernel.org ([140.211.167.34]:57625 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752070Ab0CZUkO (ORCPT ); Fri, 26 Mar 2010 16:40:14 -0400 Message-ID: <4BAD1B72.9040002@kernel.org> Date: Fri, 26 Mar 2010 13:39:14 -0700 From: Yinghai Lu User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.8) Gecko/20100228 SUSE/3.0.3-1.1.1 Thunderbird/3.0.3 MIME-Version: 1.0 To: Jan Beulich CC: hpa@zytor.com, teheo@suse.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH] free_early_partial() should permit start == end References: <4BACF0E60200007800037373@vpn.id2.novell.com> In-Reply-To: <4BACF0E60200007800037373@vpn.id2.novell.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/26/2010 09:37 AM, Jan Beulich wrote: > The per-CPU allocator, when using atom_size == PAGE_SIZE, may call > free_area_init_partial() this way. > > Signed-off-by: Jan Beulich > > --- > kernel/early_res.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > --- linux-2.6.34-rc2/kernel/early_res.c 2010-03-25 15:23:45.000000000 +0100 > +++ 2.6.34-rc2-free_early_partial-zero-size/kernel/early_res.c 2010-03-26 14:49:41.000000000 +0100 > @@ -335,10 +335,10 @@ void __init free_early_partial(u64 start > > try_next: > i = find_overlapped_early(start, end); > - if (i >= max_early_res) > + r = &early_res[i]; > + if (i >= max_early_res || !r->end) > return; > > - r = &early_res[i]; > /* hole ? */ > if (r->end >= end && r->start <= start) { > drop_range_partial(i, start, end); > > can you check if this patch work for you? Thanks Yinghai Lu Subject: [PATCH -v6] x86: do not free zero sized per cpu areas From: Ian Campbell This avoids an infinite loop in free_early_partial(). Add a warning to free_early_partial to catch future problems. -v5: put back start > end back into WARN_ONCE() -v6: use one line for if according to linus Signed-off-by: Ian Campbell Signed-off-by: Yinghai Lu Cc: Peter Zijlstra Cc: Ingo Molnar --- kernel/early_res.c | 6 ++++++ 1 file changed, 6 insertions(+) Index: linux-2.6/kernel/early_res.c =================================================================== --- linux-2.6.orig/kernel/early_res.c +++ linux-2.6/kernel/early_res.c @@ -333,6 +333,12 @@ void __init free_early_partial(u64 start struct early_res *r; int i; + if (start == end) + return; + + if (WARN_ONCE(start > end, "free_early_partial: wrong range [%#llx, %#llx]\n", start, end)) + return; + try_next: i = find_overlapped_early(start, end); if (i >= max_early_res)