From aa58a86275158c563e37e0482d49e9927a742e19 Mon Sep 17 00:00:00 2001
From: Mark Salyzyn <salyzyn@google.com>
Date: Mon, 24 Aug 2015 13:43:27 -0700
Subject: [PATCH] logd: worst uid record watermark part deux

(cherry pick from commit 49afe0d00fdc163e5b8a1ab2f859c4688613d5b8)

Only record watermark if not known, or represents the worst UID
currently under focus. This has resulted in a halving of the average
prune time in the face of heavy spam because we get less processing
spikes.

Bug: 23327476
Bug: 23681639
Bug: 23685592
Change-Id: I19f297042b9fc2c98d902695c1c36df1bf5cd6f6
---
 logd/LogBuffer.cpp | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index db3f26c72..e732b8ebf 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -467,7 +467,11 @@ void LogBuffer::prune(log_id_t id, unsigned long pruneRows, uid_t caller_uid) {
             // unmerged drop message
             if (dropped) {
                 last.add(e);
-                mLastWorstUid[id][e->getUid()] = it;
+                if ((e->getUid() == worst)
+                        || (mLastWorstUid[id].find(e->getUid())
+                            == mLastWorstUid[id].end())) {
+                    mLastWorstUid[id][e->getUid()] = it;
+                }
                 ++it;
                 continue;
             }