From: Michal Hocko <mhocko@kernel.org>
To: Baoquan He <bhe@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.org>,
linux-kernel@vger.kernel.org, robh+dt@kernel.org,
dan.j.williams@intel.com, nicolas.pitre@linaro.org,
josh@joshtriplett.org, fengguang.wu@intel.com, bp@suse.de,
andy.shevchenko@gmail.com, patrik.r.jakobsson@gmail.com,
airlied@linux.ie, kys@microsoft.com, haiyangz@microsoft.com,
sthemmin@microsoft.com, dmitry.torokhov@gmail.com,
frowand.list@gmail.com, keith.busch@intel.com,
jonathan.derrick@intel.com, lorenzo.pieralisi@arm.com,
bhelgaas@google.com, tglx@linutronix.de, brijesh.singh@amd.com,
jglisse@redhat.com, thomas.lendacky@amd.com,
gregkh@linuxfoundation.org, baiyaowei@cmss.chinamobile.com,
richard.weiyang@gmail.com, devel@linuxdriverproject.org,
linux-input@vger.kernel.org, linux-nvdimm@lists.01.org,
devicetree@vger.kernel.org
Subject: Re: [PATCH v7 4/4] kexec_file: Load kernel at top of system RAM if required
Date: Mon, 23 Jul 2018 16:34:43 +0200 [thread overview]
Message-ID: <20180723143443.GD18181@dhcp22.suse.cz> (raw)
In-Reply-To: <20180719151753.GB7147@localhost.localdomain>
On Thu 19-07-18 23:17:53, Baoquan He wrote:
> Kexec has been a formal feature in our distro, and customers owning
> those kind of very large machine can make use of this feature to speed
> up the reboot process. On uefi machine, the kexec_file loading will
> search place to put kernel under 4G from top to down. As we know, the
> 1st 4G space is DMA32 ZONE, dma, pci mmcfg, bios etc all try to consume
> it. It may have possibility to not be able to find a usable space for
> kernel/initrd. From the top down of the whole memory space, we don't
> have this worry.
I do not have the full context here but let me note that you should be
careful when doing top-down reservation because you can easily get into
hotplugable memory and break the hotremove usecase. We even warn when
this is done. See memblock_find_in_range_node
--
Michal Hocko
SUSE Labs
next prev parent reply other threads:[~2018-07-23 14:34 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-18 2:49 [PATCH v7 0/4] resource: Use list_head to link sibling resource Baoquan He
[not found] ` <20180718024944.577-1-bhe-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2018-07-18 2:49 ` [PATCH v7 1/4] resource: Move reparent_resources() to kernel/resource.c and make it public Baoquan He
2018-07-18 16:36 ` Andy Shevchenko
[not found] ` <CAHp75VdO88ydJQ9GHdaDUmAmzL6QHR=US6JiXZ1R_EEA-xWR1Q-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-07-18 16:37 ` Andy Shevchenko
[not found] ` <CAHp75Vf2yEwHhEhhQH2XN+pOQ=-skiAHZ=FgLnfVV8vcm59qeQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2018-07-19 15:18 ` Baoquan He
2018-07-18 2:49 ` [PATCH v7 2/4] resource: Use list_head to link sibling resource Baoquan He
2018-07-18 2:49 ` [PATCH v7 3/4] resource: add walk_system_ram_res_rev() Baoquan He
2018-07-18 2:49 ` [PATCH v7 4/4] kexec_file: Load kernel at top of system RAM if required Baoquan He
2018-07-18 22:33 ` Andrew Morton
[not found] ` <20180718153326.b795e9ea7835432a56cd7011-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
2018-07-19 15:17 ` Baoquan He
[not found] ` <20180719151753.GB7147-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org>
2018-07-19 19:44 ` Andrew Morton
[not found] ` <20180719124444.c893712cca2e6f2649d1bc0d-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>
2018-07-25 2:21 ` Baoquan He
2018-07-23 14:34 ` Michal Hocko [this message]
[not found] ` <20180723143443.GD18181-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2018-07-25 6:48 ` Baoquan He
2018-07-26 12:59 ` Michal Hocko
[not found] ` <20180726125957.GH28386-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2018-07-26 13:09 ` Baoquan He
2018-07-26 13:12 ` Michal Hocko
[not found] ` <20180726131242.GI28386-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2018-07-26 13:14 ` Michal Hocko
[not found] ` <20180726131420.GJ28386-2MMpYkNvuYDjFM9bn6wA6Q@public.gmane.org>
2018-07-26 13:37 ` Baoquan He
2018-07-26 14:01 ` Michal Hocko
2018-07-26 15:10 ` Baoquan He
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