Fix db_crashtest.py for prefixpercent and enable_compaction_filter (#…

…12627)

Summary:
After #12624 seeing db_stress failures due to db_crashtest.py calling it with --prefixpercent=5 --enable_compaction_filter=1

Pull Request resolved: #12627

Test Plan: watch crash test

Reviewed By: ajkr

Differential Revision: D57121592

Pulled By: pdillinger

fbshipit-source-id: 55727355a7662e67efcd22d7e353153e78e24f59

tools/db_crashtest.py

@@ -834,9 +834,10 @@ def finalize_and_sanitize(src_params):
         # verification.
         dest_params["acquire_snapshot_one_in"] = 0
         dest_params["compact_range_one_in"] = 0
-        # Give the iterator ops away to reads.
-        dest_params["readpercent"] += dest_params.get("iterpercent", 10)
+        # Redistribute to maintain 100% total
+        dest_params["readpercent"] += dest_params.get("iterpercent", 10) + dest_params.get("prefixpercent", 20)
         dest_params["iterpercent"] = 0
+        dest_params["prefixpercent"] = 0
         dest_params["check_multiget_consistency"] = 0
         dest_params["check_multiget_entity_consistency"] = 0
     if dest_params.get("disable_wal") == 1: