From: David Rientjes <rientjes@google.com>
To: Zhang Zhen <zhenzhang.zhang@huawei.com>
Cc: gregkh@linuxfoundation.org, laijs@cn.fujitsu.com,
sjenning@linux.vnet.ibm.com, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, Wang Nan <wangnan0@huawei.com>
Subject: Re: Proposal to realize hot-add *several sections one time*
Date: Wed, 11 Jun 2014 15:08:39 -0700 (PDT) [thread overview]
Message-ID: <alpine.DEB.2.02.1406111503050.27885@chino.kir.corp.google.com> (raw)
In-Reply-To: <53981D81.5060708@huawei.com>
On Wed, 11 Jun 2014, Zhang Zhen wrote:
> Hi,
>
> Now we can hot-add memory by
>
> % echo start_address_of_new_memory > /sys/devices/system/memory/probe
>
> Then, [start_address_of_new_memory, start_address_of_new_memory +
> memory_block_size] memory range is hot-added.
>
> But we can only hot-add *one section one time* by this way.
> Whether we can add an argument on behalf of the count of the sections to add ?
> So we can can hot-add *several sections one time*. Just like:
>
Not necessarily true, it depends on sections_per_block. Don't believe
Documentation/memory-hotplug.txt that suggests this is only for powerpc,
x86 and sh allow this interface as well.
> % echo start_address_of_new_memory count_of_sections > /sys/devices/system/memory/probe
>
> Then, [start_address_of_new_memory, start_address_of_new_memory +
> count_of_sections * memory_block_size] memory range is hot-added.
>
> If this proposal is reasonable, i will send a patch to realize it.
>
The problem is knowing how much memory is being onlined so that you can
definitively determine what count_of_sections should be. The number of
pages per memory section depends on PAGE_SIZE and SECTION_SIZE_BITS which
differ depending on the architectures that support this interface. So if
you support count_of_sections, it would return errno even though you have
onlined some sections.
WARNING: multiple messages have this Message-ID (diff)
From: David Rientjes <rientjes@google.com>
To: Zhang Zhen <zhenzhang.zhang@huawei.com>
Cc: gregkh@linuxfoundation.org, laijs@cn.fujitsu.com,
sjenning@linux.vnet.ibm.com, linux-kernel@vger.kernel.org,
linux-mm@kvack.org, Wang Nan <wangnan0@huawei.com>
Subject: Re: Proposal to realize hot-add *several sections one time*
Date: Wed, 11 Jun 2014 15:08:39 -0700 (PDT) [thread overview]
Message-ID: <alpine.DEB.2.02.1406111503050.27885@chino.kir.corp.google.com> (raw)
In-Reply-To: <53981D81.5060708@huawei.com>
On Wed, 11 Jun 2014, Zhang Zhen wrote:
> Hi,
>
> Now we can hot-add memory by
>
> % echo start_address_of_new_memory > /sys/devices/system/memory/probe
>
> Then, [start_address_of_new_memory, start_address_of_new_memory +
> memory_block_size] memory range is hot-added.
>
> But we can only hot-add *one section one time* by this way.
> Whether we can add an argument on behalf of the count of the sections to add ?
> So we can can hot-add *several sections one time*. Just like:
>
Not necessarily true, it depends on sections_per_block. Don't believe
Documentation/memory-hotplug.txt that suggests this is only for powerpc,
x86 and sh allow this interface as well.
> % echo start_address_of_new_memory count_of_sections > /sys/devices/system/memory/probe
>
> Then, [start_address_of_new_memory, start_address_of_new_memory +
> count_of_sections * memory_block_size] memory range is hot-added.
>
> If this proposal is reasonable, i will send a patch to realize it.
>
The problem is knowing how much memory is being onlined so that you can
definitively determine what count_of_sections should be. The number of
pages per memory section depends on PAGE_SIZE and SECTION_SIZE_BITS which
differ depending on the architectures that support this interface. So if
you support count_of_sections, it would return errno even though you have
onlined some sections.
--
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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2014-06-11 22:08 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-11 9:12 Proposal to realize hot-add *several sections one time* Zhang Zhen
2014-06-11 9:12 ` Zhang Zhen
2014-06-11 22:08 ` David Rientjes [this message]
2014-06-11 22:08 ` David Rientjes
2014-06-11 22:15 ` [patch] mm, hotplug: probe interface is available on several platforms David Rientjes
2014-06-11 22:15 ` David Rientjes
2014-06-11 22:22 ` Dave Hansen
2014-06-11 22:22 ` Dave Hansen
2014-06-12 2:41 ` Proposal to realize hot-add *several sections one time* Zhang Zhen
2014-06-12 2:41 ` Zhang Zhen
2014-06-12 7:07 ` David Rientjes
2014-06-12 7:07 ` David Rientjes
2014-06-13 7:31 ` Zhang Zhen
2014-06-13 7:31 ` Zhang Zhen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=alpine.DEB.2.02.1406111503050.27885@chino.kir.corp.google.com \
--to=rientjes@google.com \
--cc=gregkh@linuxfoundation.org \
--cc=laijs@cn.fujitsu.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=sjenning@linux.vnet.ibm.com \
--cc=wangnan0@huawei.com \
--cc=zhenzhang.zhang@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.