From: Tejun Heo <tj@kernel.org>
To: Mike Rapoport <rppt@linux.ibm.com>
Cc: Baoquan He <bhe@redhat.com>, Pingfan Liu <kernelfans@gmail.com>,
linux-acpi@vger.kernel.org, linux-mm@kvack.org,
kexec@lists.infradead.org, Tang Chen <tangchen@cn.fujitsu.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Len Brown <lenb@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Mike Rapoport <rppt@linux.vnet.ibm.com>,
Michal Hocko <mhocko@suse.com>, Jonathan Corbet <corbet@lwn.net>,
Yaowei Bai <baiyaowei@cmss.chinamobile.com>,
Pavel Tatashin <pasha.tatashin@oracle.com>,
Nicholas Piggin <npiggin@gmail.com>,
Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>,
Daniel Vacek <neelx@redhat.com>,
Mathieu Malaterre <malat@debian.org>,
Stefan Agner <stefan@agner.ch>, Dave Young <dyoung@redhat.com>,
yinghai@kernel.org, vgoyal@redhat.com,
linux-kernel@vger.kernel.org
Subject: Re: [PATCHv3 1/2] mm/memblock: extend the limit inferior of bottom-up after parsing hotplug attr
Date: Thu, 3 Jan 2019 10:47:06 -0800 [thread overview]
Message-ID: <20190103184706.GU2509588@devbig004.ftw2.facebook.com> (raw)
In-Reply-To: <20190102170537.GA3591@rapoport-lnx>
Hello,
On Wed, Jan 02, 2019 at 07:05:38PM +0200, Mike Rapoport wrote:
> I agree that currently the bottom-up allocation after the kernel text has
> issues with KASLR. But this issues are not necessarily related to the
> memory hotplug. Even with a single memory node, a bottom-up allocation will
> fail if KASLR would put the kernel near the end of node0.
>
> What I am trying to understand is whether there is a fundamental reason to
> prevent allocations from [0, kernel_start)?
>
> Maybe Tejun can recall why he suggested to start bottom-up allocations from
> kernel_end.
That's from 79442ed189ac ("mm/memblock.c: introduce bottom-up
allocation mode"). I wasn't involved in that patch, so no idea why
the restrictions were added, but FWIW it doesn't seem necessary to me.
Thanks.
--
tejun
next prev parent reply other threads:[~2019-01-03 18:47 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-28 3:00 [PATCHv3 0/2] mm/memblock: reuse memblock bottom-up allocation style Pingfan Liu
2018-12-28 3:00 ` [PATCHv3 1/2] mm/memblock: extend the limit inferior of bottom-up after parsing hotplug attr Pingfan Liu
2018-12-31 8:40 ` Mike Rapoport
2019-01-02 6:47 ` Pingfan Liu
2019-01-02 9:27 ` Mike Rapoport
2019-01-02 10:18 ` Baoquan He
2019-01-02 17:05 ` Mike Rapoport
2019-01-03 18:47 ` Tejun Heo [this message]
2019-01-04 15:09 ` Mike Rapoport
2019-01-05 3:44 ` Baoquan He
2019-01-06 6:27 ` Mike Rapoport
2019-01-08 8:50 ` Baoquan He
2019-01-07 8:37 ` Pingfan Liu
2019-01-04 5:59 ` Pingfan Liu
2019-01-04 16:20 ` Mike Rapoport
2018-12-28 3:00 ` [PATCHv3 2/2] x86/kdump: bugfix, make the behavior of crashkernel=X consistent with kaslr Pingfan Liu
2018-12-31 8:46 ` Mike Rapoport
2019-01-02 6:47 ` Pingfan Liu
2019-01-02 9:28 ` Mike Rapoport
2018-12-28 3:39 ` [PATCHv3 0/2] mm/memblock: reuse memblock bottom-up allocation style Baoquan He
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