Messages in this thread | | | Date | Fri, 21 Aug 2009 11:03:09 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [Patch 8/8] kexec: allow to shrink reserved memory |
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On Fri, 21 Aug 2009 09:59:27 +0800 Amerigo Wang <xiyou.wangcong@gmail.com> wrote:
> On Fri, Aug 21, 2009 at 09:34:52AM +0900, KAMEZAWA Hiroyuki wrote: > >On Thu, 20 Aug 2009 17:15:56 +0800 > >Amerigo Wang <amwang@redhat.com> wrote: > > > >> > The, problem is whether memmap is there or not. That's all. > >> > plz see init sequence and check there are memmap. > >> > If memory-for-crash is obtained via bootmem, > >> > Don't you try to free memory hole ? > >> > > >> > >> Hi, > >> > >> It looks like that mem_map has 'struct page' for the reserved memory, I > >> checked my "early_node_map[] active PFN ranges" output, the reserved > >> memory area for crash kernel is right in one range. Am I missing > >> something here? > >> > >> I don't know why that oops comes out, maybe because of no PTE for thoese > >> pages? > >> > >Hmm ? Could you show me the code you use ? > > (Sorry that I reply to you with my gmail, my work email can't send out > this message, probably because one of the destinations is broken... > I am the same person, don't be confused. :-) > > Sure. Below is it: > > + for (addr = end + 1; addr < crashk_res.end; addr += PAGE_SIZE) { > + printk(KERN_DEBUG "PFN is valid? %d\n", pfn_valid(addr>>PAGE_SHIFT)); > + ClearPageReserved(virt_to_page(addr)); > + init_page_count(virt_to_page(addr)); > + free_page(addr); > + totalram_pages++; > + } > > > pfn_valid() returns 1, and oops happens at ClearPageReserved(). > ('addr' is right between crashk_res.start and crashk_res.end)
Confused, if pfn_valid(addr >> PAGE_SHIFT) == true
you should do ClearPageReserved(pfn_to_page(addr >> PAGE_SHIFT));
because addr is physical address, not virtual. I guess crashk_res.end is physical address....
Thanks, -Kame
> > Thank you! >
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