On 8/5/2023 7:07 PM, Kemeng Shi wrote:
We always do zone_watermark_ok check and compaction_suitable check
together to test if compaction for target order should be runned.
Factor these code out for preparation to remove repeat code.
Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>
---
mm/compaction.c | 42 +++++++++++++++++++++++++++++-------------
1 file changed, 29 insertions(+), 13 deletions(-)
diff --git a/mm/compaction.c b/mm/compaction.c
index b5a699ed526b..26787ebb0297 100644
--- a/mm/compaction.c
+++ b/mm/compaction.c
@@ -2365,6 +2365,30 @@ 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 runned
+ */
+static inline 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);
IIUC, the watermark used in patch 8 and patch 9 is different, right?
Have you measured the impact of modifying this watermark?
+ 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)
{
@@ -2390,19 +2414,11 @@ compact_zone(struct compact_control *cc, struct capture_control *capc)
cc->migratetype = gfp_migratetype(cc->gfp_mask);
if (compaction_with_allocation_order(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;
}
/*
