commit 2ac0daaf5d03619471429d733bca77f96d1cbd29
author Robert Benea <robenea@google.com> Mon Sep 11 16:53:28 2017 -0700
committer Robert Benea <robenea@google.com> Mon Sep 11 16:57:26 2017 -0700
tree 5aac7a7e360a4b7b042609994c7f7f478ffcd9d0
parent 0349514eafcc311d5865118e4eaf3d14cfdc55bc

Allow ANDROID_LOW_MEMORY_KILLER to coexist with lmkd

For Go devices fallback to memcg/memory pressure events for LMK.
Go devices will use memcg pressure events while inkernel module
is disabled.

Bug: 64852905
Test: tested on gobo
Change-Id: I267ab00be85e324331f6c91551ba013184de817e

lmkd/lmkd.c

diff --git a/lmkd/lmkd.c b/lmkd/lmkd.c
index 08eff09..e26b227 100644
--- a/lmkd/lmkd.c
+++ b/lmkd/lmkd.c
@@ -70,6 +70,7 @@
 
 /* default to old in-kernel interface if no memory pressure events */
 static int use_inkernel_interface = 1;
+static bool has_inkernel_module;
 
 /* memory pressure level medium event */
 static int mpevfd[2];
@@ -81,6 +82,7 @@
 static bool debug_process_killing;
 static bool enable_pressure_upgrade;
 static int64_t upgrade_pressure;
+static bool is_go_device;
 
 /* control socket listen and data */
 static int ctrl_lfd;
@@ -332,7 +334,7 @@
 
     lowmem_targets_size = ntargets;
 
-    if (use_inkernel_interface) {
+    if (has_inkernel_module) {
         char minfreestr[128];
         char killpriostr[128];
 
@@ -347,9 +349,9 @@
                 strlcat(killpriostr, ",", sizeof(killpriostr));
             }
 
-            snprintf(val, sizeof(val), "%d", lowmem_minfree[i]);
+            snprintf(val, sizeof(val), "%d", use_inkernel_interface ? lowmem_minfree[i] : 0);
             strlcat(minfreestr, val, sizeof(minfreestr));
-            snprintf(val, sizeof(val), "%d", lowmem_adj[i]);
+            snprintf(val, sizeof(val), "%d", use_inkernel_interface ? lowmem_adj[i] : 0);
             strlcat(killpriostr, val, sizeof(killpriostr));
         }
 
@@ -821,7 +823,8 @@
     }
     maxevents++;
 
-    use_inkernel_interface = !access(INKERNEL_MINFREE_PATH, W_OK);
+    has_inkernel_module = !access(INKERNEL_MINFREE_PATH, W_OK);
+    use_inkernel_interface = has_inkernel_module && !is_go_device;
 
     if (use_inkernel_interface) {
         ALOGI("Using in-kernel low memory killer interface");
@@ -875,6 +878,7 @@
     debug_process_killing = property_get_bool("ro.lmk.debug", false);
     enable_pressure_upgrade = property_get_bool("ro.lmk.critical_upgrade", false);
     upgrade_pressure = (int64_t)property_get_int32("ro.lmk.upgrade_pressure", 50);
+    is_go_device = property_get_bool("ro.config.low_ram", false);
 
     mlockall(MCL_FUTURE);
     sched_setscheduler(0, SCHED_FIFO, &param);