| Message ID | 1464210007-30930-1-git-send-email-yang.shi@linaro.org |
|---|---|
| State | Accepted |
| Commit | f65e91df25aa426289cbcb580ca3183e24979fb1 |
| Headers | show |
On 5/25/2016 3:23 PM, Andrew Morton wrote: > On Wed, 25 May 2016 14:00:07 -0700 Yang Shi <yang.shi@linaro.org> wrote: > >> register_page_bootmem_info_node() is invoked in mem_init(), so it will be >> called before page_alloc_init_late() if CONFIG_DEFERRED_STRUCT_PAGE_INIT >> is enabled. But, pfn_to_nid() depends on memmap which won't be fully setup >> until page_alloc_init_late() is done, so replace pfn_to_nid() by >> early_pfn_to_nid(). > > What are the runtime effects of this fix? I didn't experience any problem without the fix. During working on the page_ext_init() fix (replace to early_pfn_to_nid()), I added printk before each pfn_to_nid() calls to check which one might be called before page_alloc_init_late(), then this one is caught. From the code perspective, it sounds not right since register_page_bootmem_info_section() may miss some pfns when CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled, just like the problem happened in page_ext_init(). Thanks, Yang >
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index caf2a14..b8ee080 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -300,7 +300,7 @@ void register_page_bootmem_info_node(struct pglist_data *pgdat) * multiple nodes we check that this pfn does not already * reside in some other nodes. */ - if (pfn_valid(pfn) && (pfn_to_nid(pfn) == node)) + if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node)) register_page_bootmem_info_section(pfn); } }
register_page_bootmem_info_node() is invoked in mem_init(), so it will be called before page_alloc_init_late() if CONFIG_DEFERRED_STRUCT_PAGE_INIT is enabled. But, pfn_to_nid() depends on memmap which won't be fully setup until page_alloc_init_late() is done, so replace pfn_to_nid() by early_pfn_to_nid(). Signed-off-by: Yang Shi <yang.shi@linaro.org> --- mm/memory_hotplug.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) -- 2.0.2