Messages in this thread | | | Date | Thu, 30 Oct 2008 09:09:58 +0900 | From | KAMEZAWA Hiroyuki <> | Subject | Re: [PATCH] memory hotplug: fix page_zone() calculation in test_pages_isolated() |
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On Wed, 29 Oct 2008 15:25:30 +0100 Gerald Schaefer <gerald.schaefer@de.ibm.com> wrote:
> From: Gerald Schaefer <gerald.schaefer@de.ibm.com> > > My last bugfix here (adding zone->lock) introduced a new problem: Using > page_zone(pfn_to_page(pfn)) to get the zone after the for() loop is wrong. > pfn will then be >= end_pfn, which may be in a different zone or not > present at all. This may lead to an addressing exception in page_zone() > or spin_lock_irqsave(). > > Now I use __first_valid_page() again after the loop to find a valid page > for page_zone(). > > Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> > Thanks.
Reviewed-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
> --- > mm/page_isolation.c | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) > > Index: linux-2.6/mm/page_isolation.c > =================================================================== > --- linux-2.6.orig/mm/page_isolation.c > +++ linux-2.6/mm/page_isolation.c > @@ -130,10 +130,11 @@ int test_pages_isolated(unsigned long st > if (page && get_pageblock_migratetype(page) != MIGRATE_ISOLATE) > break; > } > - if (pfn < end_pfn) > + page = __first_valid_page(start_pfn, end_pfn - start_pfn); > + if ((pfn < end_pfn) || !page) > return -EBUSY; > /* Check all pages are free or Marked as ISOLATED */ > - zone = page_zone(pfn_to_page(pfn)); > + zone = page_zone(page); > spin_lock_irqsave(&zone->lock, flags); > ret = __test_page_isolated_in_pageblock(start_pfn, end_pfn); > spin_unlock_irqrestore(&zone->lock, flags); > >
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