Messages in this thread | | | Date | Sat, 29 Jan 2022 00:26:28 +0000 | From | Wei Yang <> | Subject | Re: [PATCH] mm/memory_hotplug: build zonelist for managed_zone |
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On Thu, Jan 27, 2022 at 09:28:17AM +0100, Michal Hocko wrote: >On Thu 27-01-22 01:20:23, Wei Yang wrote: >> During memory hotplug, when online/offline a zone, we need to rebuild >> the zonelist for all node. There are two checks to decide whether a zone >> would be added to zonelist: >> >> * one in online_pages/offline_pages to decide necessity >> * one in build_zonerefs_node to do real add >> >> Currently we use different criteria at these two places, which is >> different from the original behavior. >> >> Originally during memory hotplug, zonelist is re-built when zone hasn't >> been populated. This in introduced in 'commit 6811378e7d8b ("[PATCH] >> wait_table and zonelist initializing for memory hotadd: update zonelists")'. >> And at that moment, build_zonelists_node() also use populated_zone() to >> decide whether the zone should be added to zonelist. >> >> While in 'commit 6aa303defb74 ("mm, vmscan: only allocate and reclaim >> from zones with pages managed by the buddy allocator")', >> build_zonelists_node() changed to use managed_zone() to add zonelist. >> But we still use populated_zone() to decide the necessity. >> >> This patch restore the original behavior by using the same criteria to >> add a zone in zonelist during memory hotplug. > >Why? >
In case we online a populated zone, but not managed. Then this zone will not be in zonelist. Right?
-- Wei Yang Help you, Help me
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