Messages in this thread | | | Date | Thu, 10 Jan 2019 10:36:43 +0530 | From | Arun KS <> | Subject | Re: [PATCH v7] mm/page_alloc.c: memory_hotplug: free pages as higher order |
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On 2019-01-10 00:26, Andrew Morton wrote: > On Wed, 09 Jan 2019 16:36:36 +0530 Arun KS <arunks@codeaurora.org> > wrote: > >> On 2019-01-09 16:27, Michal Hocko wrote: >> > On Wed 09-01-19 16:12:48, Arun KS wrote: >> > [...] >> >> It will be called once per online of a section and the arg value is >> >> always >> >> set to 0 while entering online_pages_range. >> > >> > You rare right that this will be the case in the most simple scenario. >> > But the point is that the callback can be called several times from >> > walk_system_ram_range and then your current code wouldn't work >> > properly. >> >> Thanks. Will use += > > The v8 patch > https://lore.kernel.org/lkml/1547032395-24582-1-git-send-email-arunks@codeaurora.org/T/#u > > (which you apparently sent 7 minutes after typing the above) still has > > 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); > > > Even then the code makes no sense. > > static int online_pages_range(unsigned long start_pfn, unsigned long > nr_pages, > void *arg) > { > unsigned long onlined_pages = *(unsigned long *)arg; > > if (PageReserved(pfn_to_page(start_pfn))) > onlined_pages += online_pages_blocks(start_pfn, nr_pages); > > online_mem_sections(start_pfn, start_pfn + nr_pages); > > *(unsigned long *)arg += onlined_pages; > return 0; > } > > Either the final assignment should be > > *(unsigned long *)arg = onlined_pages; > > or the initialization should be > > unsigned long onlined_pages = 0; > > > > This is becoming a tad tiresome and I'd prefer not to have to check up > on such things. Can we please get this right?
Sorry about that. Will fix it.
Regards, Arun
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