lmkd: Add command to get number of kills
Intrduce LMK_GETKILLCNT command for ActivityManager to get the number of
kills from lmkd.
Bug: 117126077
Test: used lmkd_unit_test to verify correct reporting
Change-Id: I09c720a7176b4df95efc544177cd2694f8d791be
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
diff --git a/lmkd/include/lmkd.h b/lmkd/include/lmkd.h
index e8f51da..e72d159 100644
--- a/lmkd/include/lmkd.h
+++ b/lmkd/include/lmkd.h
@@ -31,6 +31,7 @@
LMK_PROCPRIO, /* Register a process and set its oom_adj_score */
LMK_PROCREMOVE, /* Unregister a process */
LMK_PROCPURGE, /* Purge all registered processes */
+ LMK_GETKILLCNT, /* Get number of kills */
};
/*
@@ -152,6 +153,44 @@
return sizeof(int);
}
+/* LMK_GETKILLCNT packet payload */
+struct lmk_getkillcnt {
+ int min_oomadj;
+ int max_oomadj;
+};
+
+/*
+ * For LMK_GETKILLCNT packet get its payload.
+ * Warning: no checks performed, caller should ensure valid parameters.
+ */
+inline void lmkd_pack_get_getkillcnt(LMKD_CTRL_PACKET packet,
+ struct lmk_getkillcnt *params) {
+ params->min_oomadj = ntohl(packet[1]);
+ params->max_oomadj = ntohl(packet[2]);
+}
+
+/*
+ * Prepare LMK_GETKILLCNT packet and return packet size in bytes.
+ * Warning: no checks performed, caller should ensure valid parameters.
+ */
+inline size_t lmkd_pack_set_getkillcnt(LMKD_CTRL_PACKET packet,
+ struct lmk_getkillcnt *params) {
+ packet[0] = htonl(LMK_GETKILLCNT);
+ packet[1] = htonl(params->min_oomadj);
+ packet[2] = htonl(params->max_oomadj);
+ return 3 * sizeof(int);
+}
+
+/*
+ * Prepare LMK_GETKILLCNT reply packet and return packet size in bytes.
+ * Warning: no checks performed, caller should ensure valid parameters.
+ */
+inline size_t lmkd_pack_set_getkillcnt_repl(LMKD_CTRL_PACKET packet, int kill_cnt) {
+ packet[0] = htonl(LMK_GETKILLCNT);
+ packet[1] = htonl(kill_cnt);
+ return 2 * sizeof(int);
+}
+
__END_DECLS
#endif /* _LMKD_H_ */
diff --git a/lmkd/lmkd.c b/lmkd/lmkd.c
index 0a469e8..e3c4ccc 100644
--- a/lmkd/lmkd.c
+++ b/lmkd/lmkd.c
@@ -313,7 +313,20 @@
#define pid_hashfn(x) ((((x) >> 8) ^ (x)) & (PIDHASH_SZ - 1))
#define ADJTOSLOT(adj) ((adj) + -OOM_SCORE_ADJ_MIN)
-static struct adjslot_list procadjslot_list[ADJTOSLOT(OOM_SCORE_ADJ_MAX) + 1];
+#define ADJTOSLOT_COUNT (ADJTOSLOT(OOM_SCORE_ADJ_MAX) + 1)
+static struct adjslot_list procadjslot_list[ADJTOSLOT_COUNT];
+
+#define MAX_DISTINCT_OOM_ADJ 32
+#define KILLCNT_INVALID_IDX 0xFF
+/*
+ * Because killcnt array is sparse a two-level indirection is used
+ * to keep the size small. killcnt_idx stores index of the element in
+ * killcnt array. Index KILLCNT_INVALID_IDX indicates an unused slot.
+ */
+static uint8_t killcnt_idx[ADJTOSLOT_COUNT];
+static uint16_t killcnt[MAX_DISTINCT_OOM_ADJ];
+static int killcnt_free_idx = 0;
+static uint32_t killcnt_total = 0;
/* PAGE_SIZE / 1024 */
static long page_k;
@@ -644,6 +657,67 @@
memset(&pidhash[0], 0, sizeof(pidhash));
}
+static void inc_killcnt(int oomadj) {
+ int slot = ADJTOSLOT(oomadj);
+ uint8_t idx = killcnt_idx[slot];
+
+ if (idx == KILLCNT_INVALID_IDX) {
+ /* index is not assigned for this oomadj */
+ if (killcnt_free_idx < MAX_DISTINCT_OOM_ADJ) {
+ killcnt_idx[slot] = killcnt_free_idx;
+ killcnt[killcnt_free_idx] = 1;
+ killcnt_free_idx++;
+ } else {
+ ALOGW("Number of distinct oomadj levels exceeds %d",
+ MAX_DISTINCT_OOM_ADJ);
+ }
+ } else {
+ /*
+ * wraparound is highly unlikely and is detectable using total
+ * counter because it has to be equal to the sum of all counters
+ */
+ killcnt[idx]++;
+ }
+ /* increment total kill counter */
+ killcnt_total++;
+}
+
+static int get_killcnt(int min_oomadj, int max_oomadj) {
+ int slot;
+ int count = 0;
+
+ if (min_oomadj > max_oomadj)
+ return 0;
+
+ /* special case to get total kill count */
+ if (min_oomadj > OOM_SCORE_ADJ_MAX)
+ return killcnt_total;
+
+ while (min_oomadj <= max_oomadj &&
+ (slot = ADJTOSLOT(min_oomadj)) < ADJTOSLOT_COUNT) {
+ uint8_t idx = killcnt_idx[slot];
+ if (idx != KILLCNT_INVALID_IDX) {
+ count += killcnt[idx];
+ }
+ min_oomadj++;
+ }
+
+ return count;
+}
+
+static int cmd_getkillcnt(LMKD_CTRL_PACKET packet) {
+ struct lmk_getkillcnt params;
+
+ if (use_inkernel_interface) {
+ /* kernel driver does not expose this information */
+ return 0;
+ }
+
+ lmkd_pack_get_getkillcnt(packet, ¶ms);
+
+ return get_killcnt(params.min_oomadj, params.max_oomadj);
+}
+
static void cmd_target(int ntargets, LMKD_CTRL_PACKET packet) {
int i;
struct lmk_target target;
@@ -748,12 +822,28 @@
return ret;
}
+static int ctrl_data_write(int dsock_idx, char *buf, size_t bufsz) {
+ int ret = 0;
+
+ ret = TEMP_FAILURE_RETRY(write(data_sock[dsock_idx].sock, buf, bufsz));
+
+ if (ret == -1) {
+ ALOGE("control data socket write failed; errno=%d", errno);
+ } else if (ret == 0) {
+ ALOGE("Got EOF on control data socket");
+ ret = -1;
+ }
+
+ return ret;
+}
+
static void ctrl_command_handler(int dsock_idx) {
LMKD_CTRL_PACKET packet;
int len;
enum lmk_cmd cmd;
int nargs;
int targets;
+ int kill_cnt;
len = ctrl_data_read(dsock_idx, (char *)packet, CTRL_PACKET_MAX_SIZE);
if (len <= 0)
@@ -791,6 +881,14 @@
goto wronglen;
cmd_procpurge();
break;
+ case LMK_GETKILLCNT:
+ if (nargs != 2)
+ goto wronglen;
+ kill_cnt = cmd_getkillcnt(packet);
+ len = lmkd_pack_set_getkillcnt_repl(packet, kill_cnt);
+ if (ctrl_data_write(dsock_idx, (char *)packet, len) != len)
+ return;
+ break;
default:
ALOGE("Received unknown command code %d", cmd);
return;
@@ -1200,6 +1298,7 @@
/* CAP_KILL required */
r = kill(pid, SIGKILL);
+ inc_killcnt(procp->oomadj);
ALOGI("Kill '%s' (%d), uid %d, oom_adj %d to free %ldkB",
taskname, pid, uid, procp->oomadj, tasksize * page_k);
@@ -1700,6 +1799,8 @@
procadjslot_list[i].prev = &procadjslot_list[i];
}
+ memset(killcnt_idx, KILLCNT_INVALID_IDX, sizeof(killcnt_idx));
+
return 0;
}