Messages in this thread | | | Date | Wed, 16 Dec 2015 11:19:26 +0800 | From | Xishi Qiu <> | Subject | Re: [PATCH RFC] memory-hotplug: add automatic onlining policy for the newly added memory |
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On 2015/12/16 2:05, Vitaly Kuznetsov wrote:
> Currently, all newly added memory blocks remain in 'offline' state unless > someone onlines them, some linux distributions carry special udev rules > like: > > SUBSYSTEM=="memory", ACTION=="add", ATTR{state}=="offline", ATTR{state}="online" > > to make this happen automatically. This is not a great solution for virtual > machines where memory hotplug is being used to address high memory pressure > situations as such onlining is slow and a userspace process doing this > (udev) has a chance of being killed by the OOM killer as it will probably > require to allocate some memory. > > Introduce default policy for the newly added memory blocks in > /sys/devices/system/memory/hotplug_autoonline file with two possible > values: "offline" (the default) which preserves the current behavior and > "online" which causes all newly added memory blocks to go online as > soon as they're added. > > Cc: Jonathan Corbet <corbet@lwn.net> > Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > Cc: Daniel Kiper <daniel.kiper@oracle.com> > Cc: Dan Williams <dan.j.williams@intel.com> > Cc: Tang Chen <tangchen@cn.fujitsu.com> > Cc: David Vrabel <david.vrabel@citrix.com> > Cc: David Rientjes <rientjes@google.com> > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> > Cc: Gu Zheng <guz.fnst@cn.fujitsu.com> > Cc: Xishi Qiu <qiuxishi@huawei.com> > Cc: Mel Gorman <mgorman@techsingularity.net> > Cc: "K. Y. Srinivasan" <kys@microsoft.com> > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> > --- > - I was able to find previous attempts to fix the issue, e.g.: > http://marc.info/?l=linux-kernel&m=137425951924598&w=2 > http://marc.info/?l=linux-acpi&m=127186488905382 > but I'm not completely sure why it didn't work out and the solution > I suggest is not 'smart enough', thus 'RFC'.
+ CC: yanxiaofeng@inspur.com liuchangsheng@inspur.com
Hi Vitaly,
Why not use udev rule? I think it can online pages automatically.
Thanks, Xishi Qiu
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