| Message ID | 20181123114528.28802-4-mgorman@techsingularity.net (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Fragmentation avoidance improvements v5 | expand |
On 11/23/18 12:45 PM, Mel Gorman wrote: > This is a preparation patch that copies the GFP flag __GFP_KSWAPD_RECLAIM > into alloc_flags. This is a preparation patch only that avoids having to > pass gfp_mask through a long callchain in a future patch. > > Note that the setting in the fast path happens in alloc_flags_nofragment() > and it may be claimed that this has nothing to do with ALLOC_NO_FRAGMENT. > That's true in this patch but is not true later so it's done now for > easier review to show where the flag needs to be recorded. > > No functional change. > > Signed-off-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: Vlastimil Babka <vbabka@suse.cz> Small bug below: > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -3278,10 +3278,15 @@ static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) > * fragmentation between the Normal and DMA32 zones. > */ > static inline unsigned int > -alloc_flags_nofragment(struct zone *zone) > +alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask) > { > + unsigned int alloc_flags = 0; > + > + if (gfp_mask & __GFP_KSWAPD_RECLAIM) > + alloc_flags |= ALLOC_KSWAPD; > + > if (zone_idx(zone) != ZONE_NORMAL) > - return 0; > + goto out; > > /* > * If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and > @@ -3290,13 +3295,14 @@ alloc_flags_nofragment(struct zone *zone) > */ > BUILD_BUG_ON(ZONE_NORMAL - ZONE_DMA32 != 1); > if (nr_online_nodes > 1 && !populated_zone(--zone)) > - return 0; > + goto out; > > - return ALLOC_NOFRAGMENT; > +out: > + return alloc_flags; > } > #else > static inline unsigned int > -alloc_flags_nofragment(struct zone *zone) > +alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask) > { > return 0; The !CONFIG_ZONE_DMA32 version should still set ALLOC_KSWAPD, right? > } > @@ -3939,6 +3945,9 @@ gfp_to_alloc_flags(gfp_t gfp_mask) > } else if (unlikely(rt_task(current)) && !in_interrupt()) > alloc_flags |= ALLOC_HARDER; > > + if (gfp_mask & __GFP_KSWAPD_RECLAIM) > + alloc_flags |= ALLOC_KSWAPD; > + > #ifdef CONFIG_CMA > if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE) > alloc_flags |= ALLOC_CMA;
diff --git a/mm/internal.h b/mm/internal.h index 544355156c92..be826ee9dc7f 100644 --- a/mm/internal.h +++ b/mm/internal.h @@ -489,6 +489,7 @@ unsigned long reclaim_clean_pages_from_list(struct zone *zone, #else #define ALLOC_NOFRAGMENT 0x0 #endif +#define ALLOC_KSWAPD 0x200 /* allow waking of kswapd */ enum ttu_flags; struct tlbflush_unmap_batch; diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 4ba84cd2977a..e44eb68744ed 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3278,10 +3278,15 @@ static bool zone_allows_reclaim(struct zone *local_zone, struct zone *zone) * fragmentation between the Normal and DMA32 zones. */ static inline unsigned int -alloc_flags_nofragment(struct zone *zone) +alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask) { + unsigned int alloc_flags = 0; + + if (gfp_mask & __GFP_KSWAPD_RECLAIM) + alloc_flags |= ALLOC_KSWAPD; + if (zone_idx(zone) != ZONE_NORMAL) - return 0; + goto out; /* * If ZONE_DMA32 exists, assume it is the one after ZONE_NORMAL and @@ -3290,13 +3295,14 @@ alloc_flags_nofragment(struct zone *zone) */ BUILD_BUG_ON(ZONE_NORMAL - ZONE_DMA32 != 1); if (nr_online_nodes > 1 && !populated_zone(--zone)) - return 0; + goto out; - return ALLOC_NOFRAGMENT; +out: + return alloc_flags; } #else static inline unsigned int -alloc_flags_nofragment(struct zone *zone) +alloc_flags_nofragment(struct zone *zone, gfp_t gfp_mask) { return 0; } @@ -3939,6 +3945,9 @@ gfp_to_alloc_flags(gfp_t gfp_mask) } else if (unlikely(rt_task(current)) && !in_interrupt()) alloc_flags |= ALLOC_HARDER; + if (gfp_mask & __GFP_KSWAPD_RECLAIM) + alloc_flags |= ALLOC_KSWAPD; + #ifdef CONFIG_CMA if (gfpflags_to_migratetype(gfp_mask) == MIGRATE_MOVABLE) alloc_flags |= ALLOC_CMA; @@ -4170,7 +4179,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, if (!ac->preferred_zoneref->zone) goto nopage; - if (gfp_mask & __GFP_KSWAPD_RECLAIM) + if (alloc_flags & ALLOC_KSWAPD) wake_all_kswapds(order, gfp_mask, ac); /* @@ -4228,7 +4237,7 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, retry: /* Ensure kswapd doesn't accidentally go to sleep as long as we loop */ - if (gfp_mask & __GFP_KSWAPD_RECLAIM) + if (alloc_flags & ALLOC_KSWAPD) wake_all_kswapds(order, gfp_mask, ac); reserve_flags = __gfp_pfmemalloc_flags(gfp_mask); @@ -4451,7 +4460,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, int preferred_nid, * Forbid the first pass from falling back to types that fragment * memory until all local zones are considered. */ - alloc_flags |= alloc_flags_nofragment(ac.preferred_zoneref->zone); + alloc_flags |= alloc_flags_nofragment(ac.preferred_zoneref->zone, gfp_mask); /* First allocation attempt */ page = get_page_from_freelist(alloc_mask, order, alloc_flags, &ac);
This is a preparation patch that copies the GFP flag __GFP_KSWAPD_RECLAIM into alloc_flags. This is a preparation patch only that avoids having to pass gfp_mask through a long callchain in a future patch. Note that the setting in the fast path happens in alloc_flags_nofragment() and it may be claimed that this has nothing to do with ALLOC_NO_FRAGMENT. That's true in this patch but is not true later so it's done now for easier review to show where the flag needs to be recorded. No functional change. Signed-off-by: Mel Gorman <mgorman@techsingularity.net> --- mm/internal.h | 1 + mm/page_alloc.c | 25 +++++++++++++++++-------- 2 files changed, 18 insertions(+), 8 deletions(-)