Messages in this thread | | | From | Pasha Tatashin <> | Subject | Re: [PATCH] mm/page_alloc: Clean up check_for_memory | Date | Fri, 31 Aug 2018 14:04:59 +0000 |
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On 8/31/18 8:24 AM, Oscar Salvador wrote: > On Thu, Aug 30, 2018 at 01:55:29AM +0000, Pasha Tatashin wrote: >> I would re-write the above function like this: >> static void check_for_memory(pg_data_t *pgdat, int nid) >> { >> enum zone_type zone_type; >> >> for (zone_type = 0; zone_type < ZONE_MOVABLE; zone_type++) { >> if (populated_zone(&pgdat->node_zones[zone_type])) { >> node_set_state(nid, zone_type <= ZONE_NORMAL ? >> N_NORMAL_MEMORY: N_HIGH_MEMORY); >> break; >> } >> } >> } > > Hi Pavel, > > the above would not work fine. > You set either N_NORMAL_MEMORY or N_HIGH_MEMORY, but a node can have both > types of memory at the same time (on CONFIG_HIGHMEM systems). > > N_HIGH_MEMORY stands for regular or high memory > while N_NORMAL_MEMORY stands only for regular memory, > that is why we set it only in case the zone is <= ZONE_NORMAL.
Hi Oscar,
Are you saying the code that is in mainline is broken? Because we set node_set_state(nid, N_NORMAL_MEMORY); even on node with N_HIGH_MEMORY:
6826 if (N_NORMAL_MEMORY != N_HIGH_MEMORY && 6827 zone_type <= ZONE_NORMAL) 6828 node_set_state(nid, N_NORMAL_MEMORY);
Thank you, Pavel
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