mm/compaction: factor out code to test if we should run compaction for target order

We always do zone_watermark_ok check and compaction_suitable check
together to test if compaction for target order should be ran.  Factor
these code out to remove repeat code.

Link: https://lkml.kernel.org/r/20230901155141.249860-7-shikemeng@huaweicloud.com
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/compaction.c b/mm/compaction.c
index ff3426a0d9c54a7f1194f0c167d43b333de41b34..01ba298739dda5e07422ffd00798b4e494b2df15 100644 (file)
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -2378,6 +2378,30 @@ bool compaction_zonelist_suitable(struct alloc_context *ac, int order,
        return false;
 }
 
+/*
+ * Should we do compaction for target allocation order.
+ * Return COMPACT_SUCCESS if allocation for target order can be already
+ * satisfied
+ * Return COMPACT_SKIPPED if compaction for target order is likely to fail
+ * Return COMPACT_CONTINUE if compaction for target order should be ran
+ */
+static enum compact_result
+compaction_suit_allocation_order(struct zone *zone, unsigned int order,
+                                int highest_zoneidx, unsigned int alloc_flags)
+{
+       unsigned long watermark;
+
+       watermark = wmark_pages(zone, alloc_flags & ALLOC_WMARK_MASK);
+       if (zone_watermark_ok(zone, order, watermark, highest_zoneidx,
+                             alloc_flags))
+               return COMPACT_SUCCESS;
+
+       if (!compaction_suitable(zone, order, highest_zoneidx))
+               return COMPACT_SKIPPED;
+
+       return COMPACT_CONTINUE;
+}
+
 static enum compact_result
 compact_zone(struct compact_control *cc, struct capture_control *capc)
 {
@@ -2403,19 +2427,11 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
        cc->migratetype = gfp_migratetype(cc->gfp_mask);
 
        if (!is_via_compact_memory(cc->order)) {
-               unsigned long watermark;
-
-               /* Allocation can already succeed, nothing to do */
-               watermark = wmark_pages(cc->zone,
-                                       cc->alloc_flags & ALLOC_WMARK_MASK);
-               if (zone_watermark_ok(cc->zone, cc->order, watermark,
-                                     cc->highest_zoneidx, cc->alloc_flags))
-                       return COMPACT_SUCCESS;
-
-               /* Compaction is likely to fail */
-               if (!compaction_suitable(cc->zone, cc->order,
-                                        cc->highest_zoneidx))
-                       return COMPACT_SKIPPED;
+               ret = compaction_suit_allocation_order(cc->zone, cc->order,
+                                                      cc->highest_zoneidx,
+                                                      cc->alloc_flags);
+               if (ret != COMPACT_CONTINUE)
+                       return ret;
        }
 
        /*
@@ -2914,6 +2930,7 @@ static bool kcompactd_node_suitable(pg_data_t *pgdat)
        int zoneid;
        struct zone *zone;
        enum zone_type highest_zoneidx = pgdat->kcompactd_highest_zoneidx;
+       enum compact_result ret;
 
        for (zoneid = 0; zoneid <= highest_zoneidx; zoneid++) {
                zone = &pgdat->node_zones[zoneid];
@@ -2921,14 +2938,10 @@ static bool kcompactd_node_suitable(pg_data_t *pgdat)
                if (!populated_zone(zone))
                        continue;
 
-               /* Allocation can already succeed, check other zones */
-               if (zone_watermark_ok(zone, pgdat->kcompactd_max_order,
-                                     min_wmark_pages(zone),
-                                     highest_zoneidx, 0))
-                       continue;
-
-               if (compaction_suitable(zone, pgdat->kcompactd_max_order,
-                                       highest_zoneidx))
+               ret = compaction_suit_allocation_order(zone,
+                               pgdat->kcompactd_max_order,
+                               highest_zoneidx, ALLOC_WMARK_MIN);
+               if (ret == COMPACT_CONTINUE)
                        return true;
        }
 
@@ -2951,6 +2964,8 @@ static void kcompactd_do_work(pg_data_t *pgdat)
                .ignore_skip_hint = false,
                .gfp_mask = GFP_KERNEL,
        };
+       enum compact_result ret;
+
        trace_mm_compaction_kcompactd_wake(pgdat->node_id, cc.order,
                                                        cc.highest_zoneidx);
        count_compact_event(KCOMPACTD_WAKE);
@@ -2965,12 +2980,9 @@ static void kcompactd_do_work(pg_data_t *pgdat)
                if (compaction_deferred(zone, cc.order))
                        continue;
 
-               /* Allocation can already succeed, nothing to do */
-               if (zone_watermark_ok(zone, cc.order,
-                                     min_wmark_pages(zone), zoneid, 0))
-                       continue;
-
-               if (!compaction_suitable(zone, cc.order, zoneid))
+               ret = compaction_suit_allocation_order(zone,
+                               cc.order, zoneid, ALLOC_WMARK_MIN);
+               if (ret != COMPACT_CONTINUE)
                        continue;
 
                if (kthread_should_stop())