Re: [PATCH] mm: make zone_pcp_reset independ on MEMORY_HOTREMOVE

[Michal Hocko <mhocko@suse.cz>]

On Tue 23-10-12 18:14:28, Wen Congyang wrote:
> At 10/23/2012 05:37 PM, Michal Hocko Wrote:
> > 340175b7 (mm/hotplug: free zone->pageset when a zone becomes empty)
> > introduced zone_pcp_reset and hided it inside CONFIG_MEMORY_HOTREMOVE.
> > The function is since 506e5fb7 (memory-hotplug: allocate zone's pcp
> > before onlining pages) called also called from online_pages which
> 
> This patch is still in -mm tree, and I have received a report from
> Liu Yuanhan.

Yes you are right. I will resend it and ask Andrew to fold it into the
offending patch. Thanks for catching that!

> > is called outside CONFIG_MEMORY_HOTREMOVE which causes a linkage error.
> > 
> > The function, although not used outside of MEMORY_{HOTPLUT,HOTREMOVE},
> > seems like universal enough so let's keep it at its current location
> > and only remove the HOTREMOVE guard.
> > 
> > Signed-off-by: Michal Hocko <mhocko@suse.cz>
> > Cc: David Rientjes <rientjes@google.com>
> > Cc: Jiang Liu <liuj97@gmail.com>
> > Cc: Len Brown <len.brown@intel.com>
> > Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
> > Cc: Paul Mackerras <paulus@samba.org>
> > Cc: Christoph Lameter <cl@linux.com>
> > Cc: Minchan Kim <minchan.kim@gmail.com>
> > Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
> > Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
> > Cc: Dave Hansen <dave@linux.vnet.ibm.com>
> > Cc: Mel Gorman <mel@csn.ul.ie>
> > ---
> >  mm/page_alloc.c |    2 +-
> >  1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> > index e29912e..30e359c 100644
> > --- a/mm/page_alloc.c
> > +++ b/mm/page_alloc.c
> > @@ -5981,7 +5981,6 @@ void __meminit zone_pcp_update(struct zone *zone)
> >  }
> >  #endif
> >  
> > -#ifdef CONFIG_MEMORY_HOTREMOVE
> >  void zone_pcp_reset(struct zone *zone)
> >  {
> >  	unsigned long flags;
> > @@ -6001,6 +6000,7 @@ void zone_pcp_reset(struct zone *zone)
> >  	local_irq_restore(flags);
> >  }
> >  
> > +#ifdef CONFIG_MEMORY_HOTREMOVE
> >  /*
> >   * All pages in the range must be isolated before calling this.
> >   */
> 
> This patch looks find to me.
> 
> Reviewed-by: Wen Congyang <wency@cn.fujitsu.com>
> 

-- 
Michal Hocko
SUSE Labs