Messages in this thread | | | Date | Thu, 8 Sep 2011 16:21:14 +0100 | From | Stefano Stabellini <> | Subject | Re: [PATCH x86,mm] fix pgt_buf_end when memory hotplug |
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On Thu, 8 Sep 2011, Lai Jiangshan wrote: > > When I test memory hotplug, such message is always outputted when hot-adding > a memory block: > > initial kernel pagetable allocation wasted ffffffffffffffff pages
I take you are using tip/x86/mm, because that is the only branch that contains that warning.
> This message comes from init_memory_mapping(), it shows "pgt_buf_end" is > incorrect here, and I found it was caused by alloc_low_page(). > > Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> > --- > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index bbaaa00..e138e0a 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -317,7 +317,7 @@ void __init cleanup_highmap(void) > > static __ref void *alloc_low_page(unsigned long *phys) > { > - unsigned long pfn = pgt_buf_end++; > + unsigned long pfn; > void *adr; > > if (after_bootmem) { > @@ -327,6 +327,7 @@ static __ref void *alloc_low_page(unsigned long *phys) > return adr; > } > > + pfn = pgt_buf_end++; > if (pfn >= pgt_buf_top) > panic("alloc_low_page: ran out of memory");
This patch makes sense to me. It would also make sense to print the "allocation wasted" warning only if (!after_bootmem).
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