[PATCH v2] mm, lockdep: annotate reclaim context to zone reclaim too

[KOSAKI Motohiro]

> On Tue, Jan 12, 2010 at 2:16 PM, KOSAKI Motohiro
> <kosaki.motohiro@xxxxxxxxxxxxxx> wrote:
> >
> > Commit cf40bd16fd (lockdep: annotate reclaim context) introduced reclaim
> > context annotation. But it didn't annotate zone reclaim. This patch do it.
> >
> > Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
> > Cc: Nick Piggin <npiggin@xxxxxxx>
> > Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
> > Cc: Ingo Molnar <mingo@xxxxxxx>
> Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx>
> 
> I think your good explanation in previous thread is good for
> changelog. so I readd in here.
> If you mind this, feel free to discard.
> I don't care about it. :)

Thanks, refrected.

====================================================
Commit cf40bd16fd (lockdep: annotate reclaim context) introduced reclaim
context annotation. But it didn't annotate zone reclaim. This patch do it.

The point is,  commit cf40bd16fd annotate __alloc_pages_direct_reclaim
but zone-reclaim doesn't use __alloc_pages_direct_reclaim.

current call graph is

__alloc_pages_nodemask
   get_page_from_freelist
       zone_reclaim()
   __alloc_pages_slowpath
       __alloc_pages_direct_reclaim
           try_to_free_pages

Actually, if zone_reclaim_mode=1, VM never call
__alloc_pages_direct_reclaim in usual VM pressure.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Reviewed-by: Minchan Kim <minchan.kim@xxxxxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxx>
Cc: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxx>
---
 mm/vmscan.c |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 2bbee91..a039e78 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -2547,6 +2547,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
 	 * and RECLAIM_SWAP.
 	 */
 	p->flags |= PF_MEMALLOC | PF_SWAPWRITE;
+	lockdep_set_current_reclaim_state(gfp_mask);
 	reclaim_state.reclaimed_slab = 0;
 	p->reclaim_state = &reclaim_state;
 
@@ -2590,6 +2591,7 @@ static int __zone_reclaim(struct zone *zone, gfp_t gfp_mask, unsigned int order)
 
 	p->reclaim_state = NULL;
 	current->flags &= ~(PF_MEMALLOC | PF_SWAPWRITE);
+	lockdep_clear_current_reclaim_state();
 	return sc.nr_reclaimed >= nr_pages;
 }
 
-- 
1.6.6



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