Messages in this thread |  | | Date | Fri, 05 Oct 2018 12:54:45 +0530 | From | Arun KS <> | Subject | Re: [PATCH v4] memory_hotplug: Free pages as higher order |
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On 2018-10-04 20:21, Michal Hocko wrote: > On Wed 03-10-18 19:09:39, Arun KS wrote: > [...] >> +static int online_pages_blocks(unsigned long start, unsigned long >> nr_pages) >> +{ >> + unsigned long end = start + nr_pages; >> + int order, ret, onlined_pages = 0; >> + >> + while (start < end) { >> + order = min(MAX_ORDER - 1UL, __ffs(start)); >> + >> + while (start + (1UL << order) > end) >> + order--; > > this really made me scratch my head. Wouldn't it be much simpler to do > the following? > order = min(MAX_ORDER - 1, get_order(end - start))?
Yes. Much better. Will change to,
order = min(MAX_ORDER - 1, get_order(PFN_PHYS(end) - PFN_PHYS(start)));
> >> + >> + ret = (*online_page_callback)(pfn_to_page(start), order); >> + if (!ret) >> + onlined_pages += (1UL << order); >> + else if (ret > 0) >> + onlined_pages += ret; >> + >> + start += (1UL << order); >> + } >> + return onlined_pages; >> } > [...] >> -static void __init __free_pages_boot_core(struct page *page, unsigned >> int order) >> +void __free_pages_core(struct page *page, unsigned int order) >> { >> unsigned int nr_pages = 1 << order; >> struct page *p = page; >> unsigned int loop; >> >> - prefetchw(p); >> - for (loop = 0; loop < (nr_pages - 1); loop++, p++) { >> - prefetchw(p + 1); >> + for (loop = 0; loop < nr_pages; loop++, p++) { >> __ClearPageReserved(p); >> set_page_count(p, 0); >> } >> - __ClearPageReserved(p); >> - set_page_count(p, 0); >> >> page_zone(page)->managed_pages += nr_pages; >> set_page_refcounted(page); > > I think this is wort a separate patch as it is unrelated to the patch. Sure. Will split the patch.
Regards, Arun
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