logd: correct for number of elements in prune
Chatty logs would distort the average log size by elevating the
elements, but not the size. Add statistical collection for the
number of elements that report chatty, and subtract that from
the number of elements to improve the pruning estimate. Pick
minElements as 1% rather than 10% of the total with this more
accurate number of elements, to a minumum of 4.
Bug: 24511000
Change-Id: I3f36558138aa0b2a50e4fac6440c3a8505d95276
diff --git a/logd/LogBuffer.cpp b/logd/LogBuffer.cpp
index 1b68386..1de8e64 100644
--- a/logd/LogBuffer.cpp
+++ b/logd/LogBuffer.cpp
@@ -225,8 +225,11 @@
unsigned long maxSize = log_buffer_size(id);
if (sizes > maxSize) {
size_t sizeOver = sizes - ((maxSize * 9) / 10);
- size_t elements = stats.elements(id);
- size_t minElements = elements / 10;
+ size_t elements = stats.realElements(id);
+ size_t minElements = elements / 100;
+ if (minElements < minPrune) {
+ minElements = minPrune;
+ }
unsigned long pruneRows = elements * sizeOver / sizes;
if (pruneRows < minElements) {
pruneRows = minElements;