Re: [PATCH] mm: page_ext: allocate page extension though first PFN is invalid

2017-11-08 Thread Joonsoo Kim
On Wed, Nov 08, 2017 at 10:33:51PM +0900, Jaewon Kim wrote: > 2017-11-08 16:52 GMT+09:00 Joonsoo Kim : > > On Tue, Nov 07, 2017 at 06:44:47PM +0900, Jaewon Kim wrote: > >> online_page_ext and page_ext_init allocate page_ext for each section, but > >> they do not allocate if the first PFN is !pfn_pr

Re: [PATCH] mm: page_ext: allocate page extension though first PFN is invalid

2017-11-08 Thread Jaewon Kim
2017-11-08 16:52 GMT+09:00 Joonsoo Kim : > On Tue, Nov 07, 2017 at 06:44:47PM +0900, Jaewon Kim wrote: >> online_page_ext and page_ext_init allocate page_ext for each section, but >> they do not allocate if the first PFN is !pfn_present(pfn) or >> !pfn_valid(pfn). >> >> Though the first page is not

Re: [PATCH] mm: page_ext: allocate page extension though first PFN is invalid

2017-11-07 Thread Joonsoo Kim
On Tue, Nov 07, 2017 at 06:44:47PM +0900, Jaewon Kim wrote: > online_page_ext and page_ext_init allocate page_ext for each section, but > they do not allocate if the first PFN is !pfn_present(pfn) or > !pfn_valid(pfn). > > Though the first page is not valid, page_ext could be useful for other > pa

Re: [PATCH] mm: page_ext: allocate page extension though first PFN is invalid

2017-11-06 Thread Michal Hocko
On Tue 07-11-17 07:30:05, Jaewon Kim wrote: > I wonder if you want me to split and resend the 2 patches, or if you > will use this mail thread for the further discussion. Please resend -- Michal Hocko SUSE Labs

Re: [PATCH] mm: page_ext: allocate page extension though first PFN is invalid

2017-11-06 Thread Jaewon Kim
2017-11-02 17:02 GMT+09:00 Michal Hocko : > On Thu 02-11-17 15:35:07, Jaewon Kim wrote: >> online_page_ext and page_ext_init allocate page_ext for each section, but >> they do not allocate if the first PFN is !pfn_present(pfn) or >> !pfn_valid(pfn). Then section->page_ext remains as NULL. lookup_pa

Re: [PATCH] mm: page_ext: allocate page extension though first PFN is invalid

2017-11-02 Thread Michal Hocko
On Thu 02-11-17 15:35:07, Jaewon Kim wrote: > online_page_ext and page_ext_init allocate page_ext for each section, but > they do not allocate if the first PFN is !pfn_present(pfn) or > !pfn_valid(pfn). Then section->page_ext remains as NULL. lookup_page_ext > checks NULL only if CONFIG_DEBUG_VM is