Merge tag 'android-9.0.0_r21' into lineage-16.0-android-9.0.0_r21

Android 9.0.0 release 21

* tag 'android-9.0.0_r21':
  malloc: add M_PURGE mallopt flag

Change-Id: I1352461244b62d0ed02794a64f420a2bf0fbfb80

2 files changed, 13 insertions, 0 deletions

diff --git a/libc/bionic/jemalloc_wrapper.cpp b/libc/bionic/jemalloc_wrapper.cpp
index 19081a4c5..0e82066ee 100644
--- a/libc/bionic/jemalloc_wrapper.cpp
+++ b/libc/bionic/jemalloc_wrapper.cpp
@@ -79,6 +79,18 @@ int je_mallopt(int param, int value) {
       }
     }
     return 1;
+  } else if (param == M_PURGE) {
+    unsigned narenas;
+    size_t sz = sizeof(unsigned);
+    if (je_mallctl("arenas.narenas", &narenas, &sz, nullptr, 0) != 0) {
+      return 0;
+    }
+    char buffer[100];
+    snprintf(buffer, sizeof(buffer), "arena.%u.purge", narenas);
+    if (je_mallctl(buffer, nullptr, nullptr, nullptr, 0) != 0) {
+      return 0;
+    }
+    return 1;
   }
   return 0;
 }
diff --git a/libc/include/malloc.h b/libc/include/malloc.h
index 3a678a94e..d850a3b83 100644
--- a/libc/include/malloc.h
+++ b/libc/include/malloc.h
@@ -79,6 +79,7 @@ int malloc_info(int __must_be_zero, FILE* __fp) __INTRODUCED_IN(23);
 
 /* mallopt options */
 #define M_DECAY_TIME -100
+#define M_PURGE -101
 int mallopt(int __option, int __value) __INTRODUCED_IN(26);
 
 /*