Messages in this thread | | | Date | Tue, 08 Aug 2017 14:12:56 +0800 | From | Wei Wang <> | Subject | Re: [PATCH v13 4/5] mm: support reporting free page blocks |
| |
On 08/03/2017 05:11 PM, Michal Hocko wrote: > On Thu 03-08-17 14:38:18, Wei Wang wrote: > This is just too ugly and wrong actually. Never provide struct page > pointers outside of the zone->lock. What I've had in mind was to simply > walk free lists of the suitable order and call the callback for each one. > Something as simple as > > for (i = 0; i < MAX_NR_ZONES; i++) { > struct zone *zone = &pgdat->node_zones[i]; > > if (!populated_zone(zone)) > continue;
Can we directly use for_each_populated_zone(zone) here?
> spin_lock_irqsave(&zone->lock, flags); > for (order = min_order; order < MAX_ORDER; ++order) {
This appears to be covered by for_each_migratetype_order(order, mt) below.
> struct free_area *free_area = &zone->free_area[order]; > enum migratetype mt; > struct page *page; > > if (!free_area->nr_pages) > continue; > > for_each_migratetype_order(order, mt) { > list_for_each_entry(page, > &free_area->free_list[mt], lru) { > > pfn = page_to_pfn(page); > visit(opaque2, prn, 1<<order); > } > } > } > > spin_unlock_irqrestore(&zone->lock, flags); > } > > [...] >
What do you think if we further simply the above implementation like this:
for_each_populated_zone(zone) { for_each_migratetype_order_decend(1, order, mt) { spin_lock_irqsave(&zone->lock, flags); list_for_each_entry(page, &zone->free_area[order].free_list[mt], lru) { pfn = page_to_pfn(page); visit(opaque1, pfn, 1 << order); } spin_unlock_irqrestore(&zone->lock, flags); } }
Best, Wei
| |