From: Tang Chen <tangchen@cn.fujitsu.com>
To: Toshi Kani <toshi.kani@hp.com>
Cc: rjw@sisk.pl, lenb@kernel.org, tglx@linutronix.de, mingo@elte.hu,
hpa@zytor.com, akpm@linux-foundation.org, tj@kernel.org,
trenn@suse.de, yinghai@kernel.org, jiang.liu@huawei.com,
wency@cn.fujitsu.com, laijs@cn.fujitsu.com,
isimatu.yasuaki@jp.fujitsu.com, izumi.taku@jp.fujitsu.com,
mgorman@suse.de, minchan@kernel.org, mina86@mina86.com,
gong.chen@linux.intel.com, vasilis.liaskovitis@profitbricks.com,
lwoodman@redhat.com, riel@redhat.com, jweiner@redhat.com,
prarit@redhat.com, zhangyanfei@cn.fujitsu.com, x86@kernel.org,
linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, linux-acpi@vger.kernel.org
Subject: Re: [PATCH 07/11] x86, memblock: Set lowest limit for memblock_alloc_base_nid().
Date: Wed, 04 Sep 2013 10:05:51 +0800 [thread overview]
Message-ID: <5226957F.2060704@cn.fujitsu.com> (raw)
In-Reply-To: <1378255041.10300.931.camel@misato.fc.hp.com>
On 09/04/2013 08:37 AM, Toshi Kani wrote:
> On Tue, 2013-08-27 at 17:37 +0800, Tang Chen wrote:
>> memblock_alloc_base_nid() is a common API of memblock. And it calls
>> memblock_find_in_range_node() with %start = 0, which means it has no
>> limit for the lowest address by default.
>>
>> memblock_find_in_range_node(0, max_addr, size, align, nid);
>>
>> Since we introduced current_limit_low to memblock, if we have no limit
>> for the lowest address or we are not sure, we should pass
>> MEMBLOCK_ALLOC_ACCESSIBLE to %start so that it will be limited by the
>> default low limit.
>>
>> dma_contiguous_reserve() and setup_log_buf() will eventually call
>> memblock_alloc_base_nid() to allocate memory. So if the allocation order
>> is from low to high, they will allocate memory from the lowest limit
>> to higher memory.
>
> This requires the callers to use MEMBLOCK_ALLOC_ACCESSIBLE instead of 0.
> Is there a good way to make sure that all callers will follow this rule
> going forward? Perhaps, memblock_find_in_range_node() should emit some
> message if 0 is passed when current_order is low to high and the boot
> option is specified?
How about set this as the default rule:
When using from low to high order, always allocate memory from
current_limit_low.
So far, I think only movablenode boot option will use this order.
>
> Similarly, I wonder if we should have a check to the allocation size to
> make sure that all allocations will stay small in this case.
>
We can check the size. But what is the stragety after we found that the
size
is too large ? Do we refuse to allocate memory ? I don't think so.
I think only relocate_initrd() and reserve_crachkernel() could allocate
large
memory. reserve_crachkernel() is easy to reorder, but reordering
relocate_initrd()
is difficult because acpi_initrd_override() need to access to it with va.
I think on most servers, we don't need to do relocate_initrd(). initrd
will be
loaded to mapped memory in normal situation. Can we just leave it there ?
Thanks.
next prev parent reply other threads:[~2013-09-04 2:07 UTC|newest]
Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-27 9:37 [PATCH 00/11] x86, memblock: Allocate memory near kernel image before SRAT parsed Tang Chen
2013-08-27 9:37 ` [PATCH 01/11] memblock: Rename current_limit to current_limit_high in memblock Tang Chen
2013-08-27 9:37 ` [PATCH 02/11] memblock: Rename memblock_set_current_limit() to memblock_set_current_limit_high() Tang Chen
2013-08-27 9:37 ` [PATCH 03/11] memblock: Introduce lowest limit in memblock Tang Chen
2013-08-27 9:37 ` [PATCH 04/11] memblock: Introduce memblock_set_current_limit_low() to set lower limit of memblock Tang Chen
2013-08-27 9:37 ` [PATCH 05/11] memblock: Introduce allocation order to memblock Tang Chen
[not found] ` <20130905091615.GB15294@hacker.(null)>
2013-09-05 9:21 ` Tang Chen
2013-08-27 9:37 ` [PATCH 06/11] memblock: Improve memblock to support allocation from lower address Tang Chen
2013-09-04 0:24 ` Toshi Kani
2013-09-04 1:00 ` Tang Chen
2013-08-27 9:37 ` [PATCH 07/11] x86, memblock: Set lowest limit for memblock_alloc_base_nid() Tang Chen
2013-09-04 0:37 ` Toshi Kani
2013-09-04 2:05 ` Tang Chen [this message]
2013-09-04 15:22 ` Toshi Kani
2013-08-27 9:37 ` [PATCH 08/11] x86, acpi, memblock: Use __memblock_alloc_base() in acpi_initrd_override() Tang Chen
2013-08-28 0:04 ` Rafael J. Wysocki
2013-08-27 9:37 ` [PATCH 09/11] mem-hotplug: Introduce movablenode boot option to {en|dis}able using SRAT Tang Chen
2013-08-27 9:37 ` [PATCH 10/11] x86, mem-hotplug: Support initialize page tables from low to high Tang Chen
[not found] ` <20130905133027.GA23038@hacker.(null)>
2013-09-06 1:34 ` Tang Chen
[not found] ` <20130906021653.GA1062@hacker.(null)>
2013-09-06 3:09 ` Tang Chen
2013-08-27 9:37 ` [PATCH 11/11] x86, mem_hotplug: Allocate memory near kernel image before SRAT is parsed Tang Chen
2013-09-04 19:40 ` Toshi Kani
[not found] ` <20130828080311.GA608@hacker.(null)>
2013-08-28 9:34 ` [PATCH 00/11] x86, memblock: Allocate memory near kernel image before SRAT parsed Tang Chen
2013-08-28 15:19 ` Tejun Heo
2013-08-29 1:30 ` Tang Chen
[not found] ` <20130829013657.GA22599@hacker.(null)>
2013-08-29 1:53 ` Tang Chen
2013-09-02 1:03 ` Tang Chen
2013-09-04 19:22 ` Tejun Heo
2013-09-05 9:01 ` Tang Chen
[not found] ` <52299935.0302450a.26c9.ffffb240SMTPIN_ADDED_BROKEN@mx.google.com>
2013-09-06 15:15 ` Tejun Heo
2013-09-06 15:47 ` H. Peter Anvin
[not found] ` <522db781.22ab440a.41b1.ffffd825SMTPIN_ADDED_BROKEN@mx.google.com>
2013-09-09 13:58 ` Tejun Heo
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