Messages in this thread | | | Date | Tue, 09 Apr 2013 13:42:50 +0800 | From | Simon Jeons <> | Subject | Re: [PATCH 1/3] mm/page_alloc: factor out setting of pcp->high and pcp->batch. |
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Hi Cody, On 04/09/2013 01:39 AM, Cody P Schafer wrote: > On 04/06/2013 06:37 PM, Simon Jeons wrote: >> Hi Cody, >> On 04/06/2013 04:33 AM, Cody P Schafer wrote: >>> Creates pageset_set_batch() for use in setup_pageset(). >>> pageset_set_batch() imitates the functionality of >>> setup_pagelist_highmark(), but uses the boot time >>> (percpu_pagelist_fraction == 0) calculations for determining ->high >> >> Why need adjust pcp->high, pcp->batch during system running? What's the >> requirement? >> > > There is currently a sysctl (which I patch later in this series) which > allows adjusting the ->high mark (and, indirectly, ->batch). > Additionally, memory hotplug changes ->high and ->batch due to the > zone size changing (essentially, zone->managed_pages and > zone->present_pages have changed) , meaning that zone_batchsize(), > which is used at boot to set ->batch and (indirectly) ->high has a > different output.
Thanks for your explain. I'm curious about this sysctl, when need adjust the ->high, ->batch during system running except memory hotplug which will change zone size?
> > Note that in addition to the 2 users of this functionality mentioned > here, I'm currently working on anther resizer of zones (runtime NUMA > reconfiguration). >
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