lmkd: Implement kill timeout
New ro.lmk.kill_timeout_ms property defines timeout in ms after a
successful kill cycle for more kills to be considered. This is
necessary because memory pressure after a kill does not go down
instantly and system needs time to reflect new memory state. This
timeout prevents extra kills in the period immediately after a
kill cycle. By default it is set to 0 which disables this feature.
Bug: 63631020
Test: alloc-stress
Change-Id: Ia847118c8c4a659a7fc38cd5cd0042acb514ae28
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
diff --git a/lmkd/lmkd.c b/lmkd/lmkd.c
index ece4dff..77285cb 100644
--- a/lmkd/lmkd.c
+++ b/lmkd/lmkd.c
@@ -120,6 +120,7 @@
static int64_t downgrade_pressure;
static bool is_go_device;
static bool kill_heaviest_task;
+static unsigned long kill_timeout_ms;
/* control socket listen and data */
static int ctrl_lfd;
@@ -795,6 +796,12 @@
level - 1 : level);
}
+static inline unsigned long get_time_diff_ms(struct timeval *from,
+ struct timeval *to) {
+ return (to->tv_sec - from->tv_sec) * 1000 +
+ (to->tv_usec - from->tv_usec) / 1000;
+}
+
static void mp_event_common(enum vmpressure_level level) {
int ret;
unsigned long long evcount;
@@ -802,6 +809,8 @@
int64_t mem_pressure;
enum vmpressure_level lvl;
struct mem_size free_mem;
+ static struct timeval last_report_tm;
+ static unsigned long skip_count = 0;
/*
* Check all event counters from low to critical
@@ -816,6 +825,23 @@
}
}
+ if (kill_timeout_ms) {
+ struct timeval curr_tm;
+ gettimeofday(&curr_tm, NULL);
+ if (get_time_diff_ms(&last_report_tm, &curr_tm) < kill_timeout_ms) {
+ skip_count++;
+ return;
+ }
+ }
+
+ if (skip_count > 0) {
+ if (debug_process_killing) {
+ ALOGI("%lu memory pressure events were skipped after a kill!",
+ skip_count);
+ }
+ skip_count = 0;
+ }
+
if (get_free_memory(&free_mem) == 0) {
if (level == VMPRESS_LEVEL_LOW) {
record_low_pressure_levels(&free_mem);
@@ -894,6 +920,8 @@
ALOGI("Unable to free enough memory (pages freed=%d)",
pages_freed);
}
+ } else {
+ gettimeofday(&last_report_tm, NULL);
}
}
}
@@ -1081,6 +1109,8 @@
kill_heaviest_task =
property_get_bool("ro.lmk.kill_heaviest_task", true);
is_go_device = property_get_bool("ro.config.low_ram", false);
+ kill_timeout_ms =
+ (unsigned long)property_get_int32("ro.lmk.kill_timeout_ms", 0);
if (mlockall(MCL_CURRENT | MCL_FUTURE))
ALOGW("mlockall failed: errno=%d", errno);