Messages in this thread | | | Date | Wed, 09 Jan 2019 13:58:50 +0530 | From | Arun KS <> | Subject | Re: [PATCH v7] mm/page_alloc.c: memory_hotplug: free pages as higher order |
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On 2019-01-09 13:07, Michal Hocko wrote: > On Wed 09-01-19 11:28:52, Arun KS wrote: >> On 2019-01-08 23:43, Michal Hocko wrote: >> > On Tue 08-01-19 09:56:09, Alexander Duyck wrote: >> > > On Fri, 2019-01-04 at 10:31 +0530, Arun KS wrote: >> > [...] >> > > > static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, >> > > > void *arg) >> > > > { >> > > > - unsigned long i; >> > > > unsigned long onlined_pages = *(unsigned long *)arg; >> > > > - struct page *page; >> > > > >> > > > if (PageReserved(pfn_to_page(start_pfn))) >> > > > - for (i = 0; i < nr_pages; i++) { >> > > > - page = pfn_to_page(start_pfn + i); >> > > > - (*online_page_callback)(page); >> > > > - onlined_pages++; >> > > > - } >> > > > + onlined_pages = online_pages_blocks(start_pfn, nr_pages); >> > > >> > > Shouldn't this be a "+=" instead of an "="? It seems like you are >> > > going >> > > to lose your count otherwise. >> > >> > You are right of course. I should have noticed during the review. >> > Thanks! >> >> I think we don't need to. The caller function is setting onlined_pages >> = 0 >> before calling online_pages_range(). >> And there are no other reference to online_pages_range other than from >> online_pages(). > > Are you missing that we accumulate onlined_pages via > *(unsigned long *)arg = onlined_pages; > in online_pages_range?
In my testing I didn't find any problem. To match the code being replaced and to avoid any corner cases, it is better to use += Will update the patch.
Regards, Arun
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