Messages in this thread | | | Subject | Re: [PATCH V8 2/2] arm64/mm: Enable memory hot remove | From | Anshuman Khandual <> | Date | Tue, 24 Sep 2019 14:11:12 +0530 |
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On 09/23/2019 04:47 PM, Matthew Wilcox wrote: > On Mon, Sep 23, 2019 at 11:13:45AM +0530, Anshuman Khandual wrote: >> +#ifdef CONFIG_MEMORY_HOTPLUG >> +static void free_hotplug_page_range(struct page *page, size_t size) >> +{ >> + WARN_ON(!page || PageReserved(page)); > > WARN_ON(!page) isn't terribly useful. You're going to crash on the very > next line when you call page_address() anyway. If this line were > > if (WARN_ON(!page || PageReserved(page))) > return; > > it would make sense, or if it were just > > WARN_ON(PageReserved(page)) > > it would also make sense.
I guess WARN_ON(PageReserved(page)) should be good enough to make sure that page being freed here was originally allocated at runtime for a previous memory hot add operation and did not some how come from the memblock reserved area. That was the original objective for this check. Will change it.
> >> + free_pages((unsigned long)page_address(page), get_order(size)); >> +} >
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