Messages in this thread | | | Date | Wed, 12 Dec 2012 17:34:06 +0800 | From | Tang Chen <> | Subject | Re: [PATCH v3 4/5][RESEND] page_alloc: Make movablecore_map has higher priority |
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Hi Simon,
Thanks for reviewing. This logic is aimed at make movablecore_map coexist with kernelcore/movablecore.
Please see below. :)
On 12/12/2012 09:33 AM, Simon Jeons wrote: >> @@ -4839,9 +4839,17 @@ static void __init find_zone_movable_pfns_for_nodes(void) >> required_kernelcore = max(required_kernelcore, corepages); >> } >> >> - /* If kernelcore was not specified, there is no ZONE_MOVABLE */ >> - if (!required_kernelcore) >> + /* >> + * If neither kernelcore/movablecore nor movablecore_map is specified, >> + * there is no ZONE_MOVABLE. But if movablecore_map is specified, the >> + * start pfn of ZONE_MOVABLE has been stored in zone_movable_limit[]. >> + */ >> + if (!required_kernelcore) { >> + if (movablecore_map.nr_map) >> + memcpy(zone_movable_pfn, zone_movable_limit, >> + sizeof(zone_movable_pfn));
If users didn't specified kernelcore option, then zone_movable_pfn[] and zone_movable_limit[] are all the same. We skip the logic.
>> goto out; >> + } >> >> /* usable_startpfn is the lowest possible pfn ZONE_MOVABLE can be at */ >> usable_startpfn = arch_zone_lowest_possible_pfn[movable_zone]; >> @@ -4871,10 +4879,24 @@ restart: >> for_each_mem_pfn_range(i, nid,&start_pfn,&end_pfn, NULL) { >> unsigned long size_pages; >> >> + /* >> + * Find more memory for kernelcore in >> + * [zone_movable_pfn[nid], zone_movable_limit[nid]). >> + */ >> start_pfn = max(start_pfn, zone_movable_pfn[nid]); >> if (start_pfn>= end_pfn) >> continue; >> > > Hi Chen, > >> + if (zone_movable_limit[nid]) {
If users didn't give any limitation of ZONE_MOVABLE on node i, we could skip the logic too.
>> + end_pfn = min(end_pfn, zone_movable_limit[nid]);
In order to reuse the original kernelcore/movablecore logic, we keep end_pfn <= zone_movable_limit[nid]. We device [start_pfn, end_pfn) into two parts: [start_pfn, zone_movable_limit[nid]) and [zone_movable_limit[nid], end_pfn).
We just remove the second part, and go on to the original logic.
>> + /* No range left for kernelcore in this node */ >> + if (start_pfn>= end_pfn) {
Since we re-evaluated end_pfn, if we have crossed the limitation, we should stop.
>> + zone_movable_pfn[nid] = >> + zone_movable_limit[nid];
Here, we found the real limitation. That means, the lowest pfn of ZONE_MOVABLE is either zone_movable_limit[nid] or the value the original logic calculates out, which is below zone_movable_limit[nid].
>> + break;
Then we break and go on to the next node.
>> + } >> + } >> + > > Could you explain this part of codes? hard to understand. > >> /* Account for what is only usable for kernelcore */ >> if (start_pfn< usable_startpfn) { >> unsigned long kernel_pages; >> @@ -4934,12 +4956,12 @@ restart: >> if (usable_nodes&& required_kernelcore> usable_nodes) >> goto restart; >> >> +out: >> /* Align start of ZONE_MOVABLE on all nids to MAX_ORDER_NR_PAGES */ >> for (nid = 0; nid< MAX_NUMNODES; nid++) >> zone_movable_pfn[nid] = >> roundup(zone_movable_pfn[nid], MAX_ORDER_NR_PAGES); >> >> -out: >> /* restore the node_state */ >> node_states[N_HIGH_MEMORY] = saved_node_state; >> } > > >
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