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platform_system_core/lmkd/lmkd.c
Jim Blackler 1417cdbddb Add start time to LmkKillOccurred 
This is to measure an application's behavior with respect to being LMKed
(the longer an app lives before being LMKed, the better).

Bug: 119854389
Test: Manual
Change-Id: I4ef6433391c8758626334731d2b5de038e4468ae
Merged-In: I4ef6433391c8758626334731d2b5de038e4468ae
(cherry picked from I4ef6433391c8758626334731d2b5de038e4468ae)
2019-01-04 11:36:54 +00:00

1938 lines
54 KiB
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/*
* Copyright (C) 2013 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#define LOG_TAG "lowmemorykiller"
#include <errno.h>
#include <inttypes.h>
#include <pwd.h>
#include <sched.h>
#include <signal.h>
#include <stdbool.h>
#include <stdlib.h>
#include <string.h>
#include <sys/cdefs.h>
#include <sys/epoll.h>
#include <sys/eventfd.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/sysinfo.h>
#include <sys/types.h>
#include <time.h>
#include <unistd.h>
#include <cutils/properties.h>
#include <cutils/sockets.h>
#include <lmkd.h>
#include <log/log.h>
#include <log/log_event_list.h>
#include <log/log_time.h>
#ifdef LMKD_LOG_STATS
#include "statslog.h"
#endif
/*
* Define LMKD_TRACE_KILLS to record lmkd kills in kernel traces
* to profile and correlate with OOM kills
*/
#ifdef LMKD_TRACE_KILLS
#define ATRACE_TAG ATRACE_TAG_ALWAYS
#include <cutils/trace.h>
#define TRACE_KILL_START(pid) ATRACE_INT(__FUNCTION__, pid);
#define TRACE_KILL_END() ATRACE_INT(__FUNCTION__, 0);
#else /* LMKD_TRACE_KILLS */
#define TRACE_KILL_START(pid) ((void)(pid))
#define TRACE_KILL_END() ((void)0)
#endif /* LMKD_TRACE_KILLS */
#ifndef __unused
#define __unused __attribute__((__unused__))
#endif
#define MEMCG_SYSFS_PATH "/dev/memcg/"
#define MEMCG_MEMORY_USAGE "/dev/memcg/memory.usage_in_bytes"
#define MEMCG_MEMORYSW_USAGE "/dev/memcg/memory.memsw.usage_in_bytes"
#define ZONEINFO_PATH "/proc/zoneinfo"
#define MEMINFO_PATH "/proc/meminfo"
#define LINE_MAX 128
/* Android Logger event logtags (see event.logtags) */
#define MEMINFO_LOG_TAG 10195355
/* gid containing AID_SYSTEM required */
#define INKERNEL_MINFREE_PATH "/sys/module/lowmemorykiller/parameters/minfree"
#define INKERNEL_ADJ_PATH "/sys/module/lowmemorykiller/parameters/adj"
#define ARRAY_SIZE(x) (sizeof(x) / sizeof(*(x)))
#define EIGHT_MEGA (1 << 23)
#define TARGET_UPDATE_MIN_INTERVAL_MS 1000
#define NS_PER_MS (NS_PER_SEC / MS_PER_SEC)
/* Defined as ProcessList.SYSTEM_ADJ in ProcessList.java */
#define SYSTEM_ADJ (-900)
#define STRINGIFY(x) STRINGIFY_INTERNAL(x)
#define STRINGIFY_INTERNAL(x) #x
#define min(a, b) (((a) < (b)) ? (a) : (b))
#define FAIL_REPORT_RLIMIT_MS 1000
/* default to old in-kernel interface if no memory pressure events */
static bool use_inkernel_interface = true;
static bool has_inkernel_module;
/* memory pressure levels */
enum vmpressure_level {
VMPRESS_LEVEL_LOW = 0,
VMPRESS_LEVEL_MEDIUM,
VMPRESS_LEVEL_CRITICAL,
VMPRESS_LEVEL_COUNT
};
static const char *level_name[] = {
"low",
"medium",
"critical"
};
struct {
int64_t min_nr_free_pages; /* recorded but not used yet */
int64_t max_nr_free_pages;
} low_pressure_mem = { -1, -1 };
static int level_oomadj[VMPRESS_LEVEL_COUNT];
static int mpevfd[VMPRESS_LEVEL_COUNT] = { -1, -1, -1 };
static bool debug_process_killing;
static bool enable_pressure_upgrade;
static int64_t upgrade_pressure;
static int64_t downgrade_pressure;
static bool low_ram_device;
static bool kill_heaviest_task;
static unsigned long kill_timeout_ms;
static bool use_minfree_levels;
static bool per_app_memcg;
static int swap_free_low_percentage;
static android_log_context ctx;
/* data required to handle events */
struct event_handler_info {
int data;
void (*handler)(int data, uint32_t events);
};
/* data required to handle socket events */
struct sock_event_handler_info {
int sock;
struct event_handler_info handler_info;
};
/* max supported number of data connections */
#define MAX_DATA_CONN 2
/* socket event handler data */
static struct sock_event_handler_info ctrl_sock;
static struct sock_event_handler_info data_sock[MAX_DATA_CONN];
/* vmpressure event handler data */
static struct event_handler_info vmpressure_hinfo[VMPRESS_LEVEL_COUNT];
/* 3 memory pressure levels, 1 ctrl listen socket, 2 ctrl data socket */
#define MAX_EPOLL_EVENTS (1 + MAX_DATA_CONN + VMPRESS_LEVEL_COUNT)
static int epollfd;
static int maxevents;
/* OOM score values used by both kernel and framework */
#define OOM_SCORE_ADJ_MIN (-1000)
#define OOM_SCORE_ADJ_MAX 1000
static int lowmem_adj[MAX_TARGETS];
static int lowmem_minfree[MAX_TARGETS];
static int lowmem_targets_size;
/* Fields to parse in /proc/zoneinfo */
enum zoneinfo_field {
ZI_NR_FREE_PAGES = 0,
ZI_NR_FILE_PAGES,
ZI_NR_SHMEM,
ZI_NR_UNEVICTABLE,
ZI_WORKINGSET_REFAULT,
ZI_HIGH,
ZI_FIELD_COUNT
};
static const char* const zoneinfo_field_names[ZI_FIELD_COUNT] = {
"nr_free_pages",
"nr_file_pages",
"nr_shmem",
"nr_unevictable",
"workingset_refault",
"high",
};
union zoneinfo {
struct {
int64_t nr_free_pages;
int64_t nr_file_pages;
int64_t nr_shmem;
int64_t nr_unevictable;
int64_t workingset_refault;
int64_t high;
/* fields below are calculated rather than read from the file */
int64_t totalreserve_pages;
} field;
int64_t arr[ZI_FIELD_COUNT];
};
/* Fields to parse in /proc/meminfo */
enum meminfo_field {
MI_NR_FREE_PAGES = 0,
MI_CACHED,
MI_SWAP_CACHED,
MI_BUFFERS,
MI_SHMEM,
MI_UNEVICTABLE,
MI_TOTAL_SWAP,
MI_FREE_SWAP,
MI_ACTIVE_ANON,
MI_INACTIVE_ANON,
MI_ACTIVE_FILE,
MI_INACTIVE_FILE,
MI_SRECLAIMABLE,
MI_SUNRECLAIM,
MI_KERNEL_STACK,
MI_PAGE_TABLES,
MI_ION_HELP,
MI_ION_HELP_POOL,
MI_CMA_FREE,
MI_FIELD_COUNT
};
static const char* const meminfo_field_names[MI_FIELD_COUNT] = {
"MemFree:",
"Cached:",
"SwapCached:",
"Buffers:",
"Shmem:",
"Unevictable:",
"SwapTotal:",
"SwapFree:",
"Active(anon):",
"Inactive(anon):",
"Active(file):",
"Inactive(file):",
"SReclaimable:",
"SUnreclaim:",
"KernelStack:",
"PageTables:",
"ION_heap:",
"ION_heap_pool:",
"CmaFree:",
};
union meminfo {
struct {
int64_t nr_free_pages;
int64_t cached;
int64_t swap_cached;
int64_t buffers;
int64_t shmem;
int64_t unevictable;
int64_t total_swap;
int64_t free_swap;
int64_t active_anon;
int64_t inactive_anon;
int64_t active_file;
int64_t inactive_file;
int64_t sreclaimable;
int64_t sunreclaimable;
int64_t kernel_stack;
int64_t page_tables;
int64_t ion_heap;
int64_t ion_heap_pool;
int64_t cma_free;
/* fields below are calculated rather than read from the file */
int64_t nr_file_pages;
} field;
int64_t arr[MI_FIELD_COUNT];
};
enum field_match_result {
NO_MATCH,
PARSE_FAIL,
PARSE_SUCCESS
};
struct adjslot_list {
struct adjslot_list *next;
struct adjslot_list *prev;
};
struct proc {
struct adjslot_list asl;
int pid;
uid_t uid;
int oomadj;
struct proc *pidhash_next;
};
struct reread_data {
const char* const filename;
int fd;
};
#ifdef LMKD_LOG_STATS
static bool enable_stats_log;
static android_log_context log_ctx;
#endif
#define PIDHASH_SZ 1024
static struct proc *pidhash[PIDHASH_SZ];
#define pid_hashfn(x) ((((x) >> 8) ^ (x)) & (PIDHASH_SZ - 1))
#define ADJTOSLOT(adj) ((adj) + -OOM_SCORE_ADJ_MIN)
#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;
static bool parse_int64(const char* str, int64_t* ret) {
char* endptr;
long long val = strtoll(str, &endptr, 10);
if (str == endptr || val > INT64_MAX) {
return false;
}
*ret = (int64_t)val;
return true;
}
static enum field_match_result match_field(const char* cp, const char* ap,
const char* const field_names[],
int field_count, int64_t* field,
int *field_idx) {
int64_t val;
int i;
for (i = 0; i < field_count; i++) {
if (!strcmp(cp, field_names[i])) {
*field_idx = i;
return parse_int64(ap, field) ? PARSE_SUCCESS : PARSE_FAIL;
}
}
return NO_MATCH;
}
/*
* Read file content from the beginning up to max_len bytes or EOF
* whichever happens first.
*/
static ssize_t read_all(int fd, char *buf, size_t max_len)
{
ssize_t ret = 0;
off_t offset = 0;
while (max_len > 0) {
ssize_t r = TEMP_FAILURE_RETRY(pread(fd, buf, max_len, offset));
if (r == 0) {
break;
}
if (r == -1) {
return -1;
}
ret += r;
buf += r;
offset += r;
max_len -= r;
}
return ret;
}
/*
* Read a new or already opened file from the beginning.
* If the file has not been opened yet data->fd should be set to -1.
* To be used with files which are read often and possibly during high
* memory pressure to minimize file opening which by itself requires kernel
* memory allocation and might result in a stall on memory stressed system.
*/
static int reread_file(struct reread_data *data, char *buf, size_t buf_size) {
ssize_t size;
if (data->fd == -1) {
data->fd = open(data->filename, O_RDONLY | O_CLOEXEC);
if (data->fd == -1) {
ALOGE("%s open: %s", data->filename, strerror(errno));
return -1;
}
}
size = read_all(data->fd, buf, buf_size - 1);
if (size < 0) {
ALOGE("%s read: %s", data->filename, strerror(errno));
close(data->fd);
data->fd = -1;
return -1;
}
ALOG_ASSERT((size_t)size < buf_size - 1, "%s too large", data->filename);
buf[size] = 0;
return 0;
}
static struct proc *pid_lookup(int pid) {
struct proc *procp;
for (procp = pidhash[pid_hashfn(pid)]; procp && procp->pid != pid;
procp = procp->pidhash_next)
;
return procp;
}
static void adjslot_insert(struct adjslot_list *head, struct adjslot_list *new)
{
struct adjslot_list *next = head->next;
new->prev = head;
new->next = next;
next->prev = new;
head->next = new;
}
static void adjslot_remove(struct adjslot_list *old)
{
struct adjslot_list *prev = old->prev;
struct adjslot_list *next = old->next;
next->prev = prev;
prev->next = next;
}
static struct adjslot_list *adjslot_tail(struct adjslot_list *head) {
struct adjslot_list *asl = head->prev;
return asl == head ? NULL : asl;
}
static void proc_slot(struct proc *procp) {
int adjslot = ADJTOSLOT(procp->oomadj);
adjslot_insert(&procadjslot_list[adjslot], &procp->asl);
}
static void proc_unslot(struct proc *procp) {
adjslot_remove(&procp->asl);
}
static void proc_insert(struct proc *procp) {
int hval = pid_hashfn(procp->pid);
procp->pidhash_next = pidhash[hval];
pidhash[hval] = procp;
proc_slot(procp);
}
static int pid_remove(int pid) {
int hval = pid_hashfn(pid);
struct proc *procp;
struct proc *prevp;
for (procp = pidhash[hval], prevp = NULL; procp && procp->pid != pid;
procp = procp->pidhash_next)
prevp = procp;
if (!procp)
return -1;
if (!prevp)
pidhash[hval] = procp->pidhash_next;
else
prevp->pidhash_next = procp->pidhash_next;
proc_unslot(procp);
free(procp);
return 0;
}
/*
* Write a string to a file.
* Returns false if the file does not exist.
*/
static bool writefilestring(const char *path, const char *s,
bool err_if_missing) {
int fd = open(path, O_WRONLY | O_CLOEXEC);
ssize_t len = strlen(s);
ssize_t ret;
if (fd < 0) {
if (err_if_missing) {
ALOGE("Error opening %s; errno=%d", path, errno);
}
return false;
}
ret = TEMP_FAILURE_RETRY(write(fd, s, len));
if (ret < 0) {
ALOGE("Error writing %s; errno=%d", path, errno);
} else if (ret < len) {
ALOGE("Short write on %s; length=%zd", path, ret);
}
close(fd);
return true;
}
static inline long get_time_diff_ms(struct timespec *from,
struct timespec *to) {
return (to->tv_sec - from->tv_sec) * (long)MS_PER_SEC +
(to->tv_nsec - from->tv_nsec) / (long)NS_PER_MS;
}
static void cmd_procprio(LMKD_CTRL_PACKET packet) {
struct proc *procp;
char path[80];
char val[20];
int soft_limit_mult;
struct lmk_procprio params;
bool is_system_server;
struct passwd *pwdrec;
lmkd_pack_get_procprio(packet, &params);
if (params.oomadj < OOM_SCORE_ADJ_MIN ||
params.oomadj > OOM_SCORE_ADJ_MAX) {
ALOGE("Invalid PROCPRIO oomadj argument %d", params.oomadj);
return;
}
/* gid containing AID_READPROC required */
/* CAP_SYS_RESOURCE required */
/* CAP_DAC_OVERRIDE required */
snprintf(path, sizeof(path), "/proc/%d/oom_score_adj", params.pid);
snprintf(val, sizeof(val), "%d", params.oomadj);
if (!writefilestring(path, val, false)) {
ALOGW("Failed to open %s; errno=%d: process %d might have been killed",
path, errno, params.pid);
/* If this file does not exist the process is dead. */
return;
}
if (use_inkernel_interface) {
return;
}
if (per_app_memcg) {
if (params.oomadj >= 900) {
soft_limit_mult = 0;
} else if (params.oomadj >= 800) {
soft_limit_mult = 0;
} else if (params.oomadj >= 700) {
soft_limit_mult = 0;
} else if (params.oomadj >= 600) {
// Launcher should be perceptible, don't kill it.
params.oomadj = 200;
soft_limit_mult = 1;
} else if (params.oomadj >= 500) {
soft_limit_mult = 0;
} else if (params.oomadj >= 400) {
soft_limit_mult = 0;
} else if (params.oomadj >= 300) {
soft_limit_mult = 1;
} else if (params.oomadj >= 200) {
soft_limit_mult = 8;
} else if (params.oomadj >= 100) {
soft_limit_mult = 10;
} else if (params.oomadj >= 0) {
soft_limit_mult = 20;
} else {
// Persistent processes will have a large
// soft limit 512MB.
soft_limit_mult = 64;
}
snprintf(path, sizeof(path), MEMCG_SYSFS_PATH
"apps/uid_%d/pid_%d/memory.soft_limit_in_bytes",
params.uid, params.pid);
snprintf(val, sizeof(val), "%d", soft_limit_mult * EIGHT_MEGA);
/*
* system_server process has no memcg under /dev/memcg/apps but should be
* registered with lmkd. This is the best way so far to identify it.
*/
is_system_server = (params.oomadj == SYSTEM_ADJ &&
(pwdrec = getpwnam("system")) != NULL &&
params.uid == pwdrec->pw_uid);
writefilestring(path, val, !is_system_server);
}
procp = pid_lookup(params.pid);
if (!procp) {
procp = malloc(sizeof(struct proc));
if (!procp) {
// Oh, the irony. May need to rebuild our state.
return;
}
procp->pid = params.pid;
procp->uid = params.uid;
procp->oomadj = params.oomadj;
proc_insert(procp);
} else {
proc_unslot(procp);
procp->oomadj = params.oomadj;
proc_slot(procp);
}
}
static void cmd_procremove(LMKD_CTRL_PACKET packet) {
struct lmk_procremove params;
if (use_inkernel_interface) {
return;
}
lmkd_pack_get_procremove(packet, &params);
/*
* WARNING: After pid_remove() procp is freed and can't be used!
* Therefore placed at the end of the function.
*/
pid_remove(params.pid);
}
static void cmd_procpurge() {
int i;
struct proc *procp;
struct proc *next;
if (use_inkernel_interface) {
return;
}
for (i = 0; i <= ADJTOSLOT(OOM_SCORE_ADJ_MAX); i++) {
procadjslot_list[i].next = &procadjslot_list[i];
procadjslot_list[i].prev = &procadjslot_list[i];
}
for (i = 0; i < PIDHASH_SZ; i++) {
procp = pidhash[i];
while (procp) {
next = procp->pidhash_next;
free(procp);
procp = next;
}
}
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, &params);
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;
char minfree_str[PROPERTY_VALUE_MAX];
char *pstr = minfree_str;
char *pend = minfree_str + sizeof(minfree_str);
static struct timespec last_req_tm;
struct timespec curr_tm;
if (ntargets < 1 || ntargets > (int)ARRAY_SIZE(lowmem_adj))
return;
/*
* Ratelimit minfree updates to once per TARGET_UPDATE_MIN_INTERVAL_MS
* to prevent DoS attacks
*/
if (clock_gettime(CLOCK_MONOTONIC_COARSE, &curr_tm) != 0) {
ALOGE("Failed to get current time");
return;
}
if (get_time_diff_ms(&last_req_tm, &curr_tm) <
TARGET_UPDATE_MIN_INTERVAL_MS) {
ALOGE("Ignoring frequent updated to lmkd limits");
return;
}
last_req_tm = curr_tm;
for (i = 0; i < ntargets; i++) {
lmkd_pack_get_target(packet, i, &target);
lowmem_minfree[i] = target.minfree;
lowmem_adj[i] = target.oom_adj_score;
pstr += snprintf(pstr, pend - pstr, "%d:%d,", target.minfree,
target.oom_adj_score);
if (pstr >= pend) {
/* if no more space in the buffer then terminate the loop */
pstr = pend;
break;
}
}
lowmem_targets_size = ntargets;
/* Override the last extra comma */
pstr[-1] = '\0';
property_set("sys.lmk.minfree_levels", minfree_str);
if (has_inkernel_module) {
char minfreestr[128];
char killpriostr[128];
minfreestr[0] = '\0';
killpriostr[0] = '\0';
for (i = 0; i < lowmem_targets_size; i++) {
char val[40];
if (i) {
strlcat(minfreestr, ",", sizeof(minfreestr));
strlcat(killpriostr, ",", sizeof(killpriostr));
}
snprintf(val, sizeof(val), "%d", use_inkernel_interface ? lowmem_minfree[i] : 0);
strlcat(minfreestr, val, sizeof(minfreestr));
snprintf(val, sizeof(val), "%d", use_inkernel_interface ? lowmem_adj[i] : 0);
strlcat(killpriostr, val, sizeof(killpriostr));
}
writefilestring(INKERNEL_MINFREE_PATH, minfreestr, true);
writefilestring(INKERNEL_ADJ_PATH, killpriostr, true);
}
}
static void ctrl_data_close(int dsock_idx) {
struct epoll_event epev;
ALOGI("closing lmkd data connection");
if (epoll_ctl(epollfd, EPOLL_CTL_DEL, data_sock[dsock_idx].sock, &epev) == -1) {
// Log a warning and keep going
ALOGW("epoll_ctl for data connection socket failed; errno=%d", errno);
}
maxevents--;
close(data_sock[dsock_idx].sock);
data_sock[dsock_idx].sock = -1;
}
static int ctrl_data_read(int dsock_idx, char *buf, size_t bufsz) {
int ret = 0;
ret = TEMP_FAILURE_RETRY(read(data_sock[dsock_idx].sock, buf, bufsz));
if (ret == -1) {
ALOGE("control data socket read failed; errno=%d", errno);
} else if (ret == 0) {
ALOGE("Got EOF on control data socket");
ret = -1;
}
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)
return;
if (len < (int)sizeof(int)) {
ALOGE("Wrong control socket read length len=%d", len);
return;
}
cmd = lmkd_pack_get_cmd(packet);
nargs = len / sizeof(int) - 1;
if (nargs < 0)
goto wronglen;
switch(cmd) {
case LMK_TARGET:
targets = nargs / 2;
if (nargs & 0x1 || targets > (int)ARRAY_SIZE(lowmem_adj))
goto wronglen;
cmd_target(targets, packet);
break;
case LMK_PROCPRIO:
if (nargs != 3)
goto wronglen;
cmd_procprio(packet);
break;
case LMK_PROCREMOVE:
if (nargs != 1)
goto wronglen;
cmd_procremove(packet);
break;
case LMK_PROCPURGE:
if (nargs != 0)
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;
}
return;
wronglen:
ALOGE("Wrong control socket read length cmd=%d len=%d", cmd, len);
}
static void ctrl_data_handler(int data, uint32_t events) {
if (events & EPOLLIN) {
ctrl_command_handler(data);
}
}
static int get_free_dsock() {
for (int i = 0; i < MAX_DATA_CONN; i++) {
if (data_sock[i].sock < 0) {
return i;
}
}
return -1;
}
static void ctrl_connect_handler(int data __unused, uint32_t events __unused) {
struct epoll_event epev;
int free_dscock_idx = get_free_dsock();
if (free_dscock_idx < 0) {
/*
* Number of data connections exceeded max supported. This should not
* happen but if it does we drop all existing connections and accept
* the new one. This prevents inactive connections from monopolizing
* data socket and if we drop ActivityManager connection it will
* immediately reconnect.
*/
for (int i = 0; i < MAX_DATA_CONN; i++) {
ctrl_data_close(i);
}
free_dscock_idx = 0;
}
data_sock[free_dscock_idx].sock = accept(ctrl_sock.sock, NULL, NULL);
if (data_sock[free_dscock_idx].sock < 0) {
ALOGE("lmkd control socket accept failed; errno=%d", errno);
return;
}
ALOGI("lmkd data connection established");
/* use data to store data connection idx */
data_sock[free_dscock_idx].handler_info.data = free_dscock_idx;
data_sock[free_dscock_idx].handler_info.handler = ctrl_data_handler;
epev.events = EPOLLIN;
epev.data.ptr = (void *)&(data_sock[free_dscock_idx].handler_info);
if (epoll_ctl(epollfd, EPOLL_CTL_ADD, data_sock[free_dscock_idx].sock, &epev) == -1) {
ALOGE("epoll_ctl for data connection socket failed; errno=%d", errno);
ctrl_data_close(free_dscock_idx);
return;
}
maxevents++;
}
#ifdef LMKD_LOG_STATS
static void memory_stat_parse_line(char* line, struct memory_stat* mem_st) {
char key[LINE_MAX + 1];
int64_t value;
sscanf(line, "%" STRINGIFY(LINE_MAX) "s %" SCNd64 "", key, &value);
if (strcmp(key, "total_") < 0) {
return;
}
if (!strcmp(key, "total_pgfault"))
mem_st->pgfault = value;
else if (!strcmp(key, "total_pgmajfault"))
mem_st->pgmajfault = value;
else if (!strcmp(key, "total_rss"))
mem_st->rss_in_bytes = value;
else if (!strcmp(key, "total_cache"))
mem_st->cache_in_bytes = value;
else if (!strcmp(key, "total_swap"))
mem_st->swap_in_bytes = value;
}
static int memory_stat_from_cgroup(struct memory_stat* mem_st, int pid, uid_t uid) {
FILE *fp;
char buf[PATH_MAX];
snprintf(buf, sizeof(buf), MEMCG_PROCESS_MEMORY_STAT_PATH, uid, pid);
fp = fopen(buf, "r");
if (fp == NULL) {
ALOGE("%s open failed: %s", buf, strerror(errno));
return -1;
}
while (fgets(buf, PAGE_SIZE, fp) != NULL) {
memory_stat_parse_line(buf, mem_st);
}
fclose(fp);
return 0;
}
static int memory_stat_from_procfs(struct memory_stat* mem_st, int pid) {
char path[PATH_MAX];
char buffer[PROC_STAT_BUFFER_SIZE];
int fd, ret;
snprintf(path, sizeof(path), PROC_STAT_FILE_PATH, pid);
if ((fd = open(path, O_RDONLY | O_CLOEXEC)) < 0) {
ALOGE("%s open failed: %s", path, strerror(errno));
return -1;
}
ret = read(fd, buffer, sizeof(buffer));
if (ret < 0) {
ALOGE("%s read failed: %s", path, strerror(errno));
close(fd);
return -1;
}
close(fd);
// field 10 is pgfault
// field 12 is pgmajfault
// field 22 is starttime
// field 24 is rss_in_pages
int64_t pgfault = 0, pgmajfault = 0, starttime = 0, rss_in_pages = 0;
if (sscanf(buffer,
"%*u %*s %*s %*d %*d %*d %*d %*d %*d %" SCNd64 " %*d "
"%" SCNd64 " %*d %*u %*u %*d %*d %*d %*d %*d %*d "
"%" SCNd64 " %*d %" SCNd64 "",
&pgfault, &pgmajfault, &starttime, &rss_in_pages) != 4) {
return -1;
}
mem_st->pgfault = pgfault;
mem_st->pgmajfault = pgmajfault;
mem_st->rss_in_bytes = (rss_in_pages * PAGE_SIZE);
mem_st->process_start_time_ns = starttime * (NS_PER_SEC / sysconf(_SC_CLK_TCK));
return 0;
}
#endif
/* /prop/zoneinfo parsing routines */
static int64_t zoneinfo_parse_protection(char *cp) {
int64_t max = 0;
long long zoneval;
char *save_ptr;
for (cp = strtok_r(cp, "(), ", &save_ptr); cp;
cp = strtok_r(NULL, "), ", &save_ptr)) {
zoneval = strtoll(cp, &cp, 0);
if (zoneval > max) {
max = (zoneval > INT64_MAX) ? INT64_MAX : zoneval;
}
}
return max;
}
static bool zoneinfo_parse_line(char *line, union zoneinfo *zi) {
char *cp = line;
char *ap;
char *save_ptr;
int64_t val;
int field_idx;
cp = strtok_r(line, " ", &save_ptr);
if (!cp) {
return true;
}
if (!strcmp(cp, "protection:")) {
ap = strtok_r(NULL, ")", &save_ptr);
} else {
ap = strtok_r(NULL, " ", &save_ptr);
}
if (!ap) {
return true;
}
switch (match_field(cp, ap, zoneinfo_field_names,
ZI_FIELD_COUNT, &val, &field_idx)) {
case (PARSE_SUCCESS):
zi->arr[field_idx] += val;
break;
case (NO_MATCH):
if (!strcmp(cp, "protection:")) {
zi->field.totalreserve_pages +=
zoneinfo_parse_protection(ap);
}
break;
case (PARSE_FAIL):
default:
return false;
}
return true;
}
static int zoneinfo_parse(union zoneinfo *zi) {
static struct reread_data file_data = {
.filename = ZONEINFO_PATH,
.fd = -1,
};
char buf[PAGE_SIZE];
char *save_ptr;
char *line;
memset(zi, 0, sizeof(union zoneinfo));
if (reread_file(&file_data, buf, sizeof(buf)) < 0) {
return -1;
}
for (line = strtok_r(buf, "\n", &save_ptr); line;
line = strtok_r(NULL, "\n", &save_ptr)) {
if (!zoneinfo_parse_line(line, zi)) {
ALOGE("%s parse error", file_data.filename);
return -1;
}
}
zi->field.totalreserve_pages += zi->field.high;
return 0;
}
/* /prop/meminfo parsing routines */
static bool meminfo_parse_line(char *line, union meminfo *mi) {
char *cp = line;
char *ap;
char *save_ptr;
int64_t val;
int field_idx;
enum field_match_result match_res;
cp = strtok_r(line, " ", &save_ptr);
if (!cp) {
return false;
}
ap = strtok_r(NULL, " ", &save_ptr);
if (!ap) {
return false;
}
match_res = match_field(cp, ap, meminfo_field_names, MI_FIELD_COUNT,
&val, &field_idx);
if (match_res == PARSE_SUCCESS) {
mi->arr[field_idx] = val / page_k;
}
return (match_res != PARSE_FAIL);
}
static int meminfo_parse(union meminfo *mi) {
static struct reread_data file_data = {
.filename = MEMINFO_PATH,
.fd = -1,
};
char buf[PAGE_SIZE];
char *save_ptr;
char *line;
memset(mi, 0, sizeof(union meminfo));
if (reread_file(&file_data, buf, sizeof(buf)) < 0) {
return -1;
}
for (line = strtok_r(buf, "\n", &save_ptr); line;
line = strtok_r(NULL, "\n", &save_ptr)) {
if (!meminfo_parse_line(line, mi)) {
ALOGE("%s parse error", file_data.filename);
return -1;
}
}
mi->field.nr_file_pages = mi->field.cached + mi->field.swap_cached +
mi->field.buffers;
return 0;
}
static void meminfo_log(union meminfo *mi) {
for (int field_idx = 0; field_idx < MI_FIELD_COUNT; field_idx++) {
android_log_write_int32(ctx, (int32_t)min(mi->arr[field_idx] * page_k, INT32_MAX));
}
android_log_write_list(ctx, LOG_ID_EVENTS);
android_log_reset(ctx);
}
static int proc_get_size(int pid) {
char path[PATH_MAX];
char line[LINE_MAX];
int fd;
int rss = 0;
int total;
ssize_t ret;
/* gid containing AID_READPROC required */
snprintf(path, PATH_MAX, "/proc/%d/statm", pid);
fd = open(path, O_RDONLY | O_CLOEXEC);
if (fd == -1)
return -1;
ret = read_all(fd, line, sizeof(line) - 1);
if (ret < 0) {
close(fd);
return -1;
}
sscanf(line, "%d %d ", &total, &rss);
close(fd);
return rss;
}
static char *proc_get_name(int pid) {
char path[PATH_MAX];
static char line[LINE_MAX];
int fd;
char *cp;
ssize_t ret;
/* gid containing AID_READPROC required */
snprintf(path, PATH_MAX, "/proc/%d/cmdline", pid);
fd = open(path, O_RDONLY | O_CLOEXEC);
if (fd == -1)
return NULL;
ret = read_all(fd, line, sizeof(line) - 1);
close(fd);
if (ret < 0) {
return NULL;
}
cp = strchr(line, ' ');
if (cp)
*cp = '\0';
return line;
}
static struct proc *proc_adj_lru(int oomadj) {
return (struct proc *)adjslot_tail(&procadjslot_list[ADJTOSLOT(oomadj)]);
}
static struct proc *proc_get_heaviest(int oomadj) {
struct adjslot_list *head = &procadjslot_list[ADJTOSLOT(oomadj)];
struct adjslot_list *curr = head->next;
struct proc *maxprocp = NULL;
int maxsize = 0;
while (curr != head) {
int pid = ((struct proc *)curr)->pid;
int tasksize = proc_get_size(pid);
if (tasksize <= 0) {
struct adjslot_list *next = curr->next;
pid_remove(pid);
curr = next;
} else {
if (tasksize > maxsize) {
maxsize = tasksize;
maxprocp = (struct proc *)curr;
}
curr = curr->next;
}
}
return maxprocp;
}
static int last_killed_pid = -1;
/* Kill one process specified by procp. Returns the size of the process killed */
static int kill_one_process(struct proc* procp) {
int pid = procp->pid;
uid_t uid = procp->uid;
char *taskname;
int tasksize;
int r;
int result = -1;
#ifdef LMKD_LOG_STATS
struct memory_stat mem_st = {};
int memory_stat_parse_result = -1;
#endif
taskname = proc_get_name(pid);
if (!taskname) {
goto out;
}
tasksize = proc_get_size(pid);
if (tasksize <= 0) {
goto out;
}
#ifdef LMKD_LOG_STATS
if (enable_stats_log) {
if (per_app_memcg) {
memory_stat_parse_result = memory_stat_from_cgroup(&mem_st, pid, uid);
} else {
memory_stat_parse_result = memory_stat_from_procfs(&mem_st, pid);
}
}
#endif
TRACE_KILL_START(pid);
/* 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);
TRACE_KILL_END();
last_killed_pid = pid;
if (r) {
ALOGE("kill(%d): errno=%d", pid, errno);
goto out;
} else {
#ifdef LMKD_LOG_STATS
if (memory_stat_parse_result == 0) {
stats_write_lmk_kill_occurred(log_ctx, LMK_KILL_OCCURRED, uid, taskname,
procp->oomadj, mem_st.pgfault, mem_st.pgmajfault, mem_st.rss_in_bytes,
mem_st.cache_in_bytes, mem_st.swap_in_bytes, mem_st.process_start_time_ns);
} else if (enable_stats_log) {
stats_write_lmk_kill_occurred(log_ctx, LMK_KILL_OCCURRED, uid, taskname, procp->oomadj,
-1, -1, tasksize * BYTES_IN_KILOBYTE, -1, -1, -1);
}
#endif
result = tasksize;
}
out:
/*
* WARNING: After pid_remove() procp is freed and can't be used!
* Therefore placed at the end of the function.
*/
pid_remove(pid);
return result;
}
/*
* Find one process to kill at or above the given oom_adj level.
* Returns size of the killed process.
*/
static int find_and_kill_process(int min_score_adj) {
int i;
int killed_size = 0;
#ifdef LMKD_LOG_STATS
bool lmk_state_change_start = false;
#endif
for (i = OOM_SCORE_ADJ_MAX; i >= min_score_adj; i--) {
struct proc *procp;
while (true) {
procp = kill_heaviest_task ?
proc_get_heaviest(i) : proc_adj_lru(i);
if (!procp)
break;
killed_size = kill_one_process(procp);
if (killed_size >= 0) {
#ifdef LMKD_LOG_STATS
if (enable_stats_log && !lmk_state_change_start) {
lmk_state_change_start = true;
stats_write_lmk_state_changed(log_ctx, LMK_STATE_CHANGED,
LMK_STATE_CHANGE_START);
}
#endif
break;
}
}
if (killed_size) {
break;
}
}
#ifdef LMKD_LOG_STATS
if (enable_stats_log && lmk_state_change_start) {
stats_write_lmk_state_changed(log_ctx, LMK_STATE_CHANGED, LMK_STATE_CHANGE_STOP);
}
#endif
return killed_size;
}
static int64_t get_memory_usage(struct reread_data *file_data) {
int ret;
int64_t mem_usage;
char buf[32];
if (reread_file(file_data, buf, sizeof(buf)) < 0) {
return -1;
}
if (!parse_int64(buf, &mem_usage)) {
ALOGE("%s parse error", file_data->filename);
return -1;
}
if (mem_usage == 0) {
ALOGE("No memory!");
return -1;
}
return mem_usage;
}
void record_low_pressure_levels(union meminfo *mi) {
if (low_pressure_mem.min_nr_free_pages == -1 ||
low_pressure_mem.min_nr_free_pages > mi->field.nr_free_pages) {
if (debug_process_killing) {
ALOGI("Low pressure min memory update from %" PRId64 " to %" PRId64,
low_pressure_mem.min_nr_free_pages, mi->field.nr_free_pages);
}
low_pressure_mem.min_nr_free_pages = mi->field.nr_free_pages;
}
/*
* Free memory at low vmpressure events occasionally gets spikes,
* possibly a stale low vmpressure event with memory already
* freed up (no memory pressure should have been reported).
* Ignore large jumps in max_nr_free_pages that would mess up our stats.
*/
if (low_pressure_mem.max_nr_free_pages == -1 ||
(low_pressure_mem.max_nr_free_pages < mi->field.nr_free_pages &&
mi->field.nr_free_pages - low_pressure_mem.max_nr_free_pages <
low_pressure_mem.max_nr_free_pages * 0.1)) {
if (debug_process_killing) {
ALOGI("Low pressure max memory update from %" PRId64 " to %" PRId64,
low_pressure_mem.max_nr_free_pages, mi->field.nr_free_pages);
}
low_pressure_mem.max_nr_free_pages = mi->field.nr_free_pages;
}
}
enum vmpressure_level upgrade_level(enum vmpressure_level level) {
return (enum vmpressure_level)((level < VMPRESS_LEVEL_CRITICAL) ?
level + 1 : level);
}
enum vmpressure_level downgrade_level(enum vmpressure_level level) {
return (enum vmpressure_level)((level > VMPRESS_LEVEL_LOW) ?
level - 1 : level);
}
static bool is_kill_pending(void) {
char buf[24];
if (last_killed_pid < 0) {
return false;
}
snprintf(buf, sizeof(buf), "/proc/%d/", last_killed_pid);
if (access(buf, F_OK) == 0) {
return true;
}
// reset last killed PID because there's nothing pending
last_killed_pid = -1;
return false;
}
static void mp_event_common(int data, uint32_t events __unused) {
int ret;
unsigned long long evcount;
int64_t mem_usage, memsw_usage;
int64_t mem_pressure;
enum vmpressure_level lvl;
union meminfo mi;
union zoneinfo zi;
struct timespec curr_tm;
static struct timespec last_kill_tm;
static unsigned long kill_skip_count = 0;
enum vmpressure_level level = (enum vmpressure_level)data;
long other_free = 0, other_file = 0;
int min_score_adj;
int minfree = 0;
static struct reread_data mem_usage_file_data = {
.filename = MEMCG_MEMORY_USAGE,
.fd = -1,
};
static struct reread_data memsw_usage_file_data = {
.filename = MEMCG_MEMORYSW_USAGE,
.fd = -1,
};
/*
* Check all event counters from low to critical
* and upgrade to the highest priority one. By reading
* eventfd we also reset the event counters.
*/
for (lvl = VMPRESS_LEVEL_LOW; lvl < VMPRESS_LEVEL_COUNT; lvl++) {
if (mpevfd[lvl] != -1 &&
TEMP_FAILURE_RETRY(read(mpevfd[lvl],
&evcount, sizeof(evcount))) > 0 &&
evcount > 0 && lvl > level) {
level = lvl;
}
}
if (clock_gettime(CLOCK_MONOTONIC_COARSE, &curr_tm) != 0) {
ALOGE("Failed to get current time");
return;
}
if (kill_timeout_ms) {
// If we're within the timeout, see if there's pending reclaim work
// from the last killed process. If there is (as evidenced by
// /proc/<pid> continuing to exist), skip killing for now.
if ((get_time_diff_ms(&last_kill_tm, &curr_tm) < kill_timeout_ms) &&
(low_ram_device || is_kill_pending())) {
kill_skip_count++;
return;
}
}
if (kill_skip_count > 0) {
ALOGI("%lu memory pressure events were skipped after a kill!",
kill_skip_count);
kill_skip_count = 0;
}
if (meminfo_parse(&mi) < 0 || zoneinfo_parse(&zi) < 0) {
ALOGE("Failed to get free memory!");
return;
}
if (use_minfree_levels) {
int i;
other_free = mi.field.nr_free_pages - zi.field.totalreserve_pages;
if (mi.field.nr_file_pages > (mi.field.shmem + mi.field.unevictable + mi.field.swap_cached)) {
other_file = (mi.field.nr_file_pages - mi.field.shmem -
mi.field.unevictable - mi.field.swap_cached);
} else {
other_file = 0;
}
min_score_adj = OOM_SCORE_ADJ_MAX + 1;
for (i = 0; i < lowmem_targets_size; i++) {
minfree = lowmem_minfree[i];
if (other_free < minfree && other_file < minfree) {
min_score_adj = lowmem_adj[i];
break;
}
}
if (min_score_adj == OOM_SCORE_ADJ_MAX + 1) {
if (debug_process_killing) {
ALOGI("Ignore %s memory pressure event "
"(free memory=%ldkB, cache=%ldkB, limit=%ldkB)",
level_name[level], other_free * page_k, other_file * page_k,
(long)lowmem_minfree[lowmem_targets_size - 1] * page_k);
}
return;
}
goto do_kill;
}
if (level == VMPRESS_LEVEL_LOW) {
record_low_pressure_levels(&mi);
}
if (level_oomadj[level] > OOM_SCORE_ADJ_MAX) {
/* Do not monitor this pressure level */
return;
}
if ((mem_usage = get_memory_usage(&mem_usage_file_data)) < 0) {
goto do_kill;
}
if ((memsw_usage = get_memory_usage(&memsw_usage_file_data)) < 0) {
goto do_kill;
}
// Calculate percent for swappinness.
mem_pressure = (mem_usage * 100) / memsw_usage;
if (enable_pressure_upgrade && level != VMPRESS_LEVEL_CRITICAL) {
// We are swapping too much.
if (mem_pressure < upgrade_pressure) {
level = upgrade_level(level);
if (debug_process_killing) {
ALOGI("Event upgraded to %s", level_name[level]);
}
}
}
// If we still have enough swap space available, check if we want to
// ignore/downgrade pressure events.
if (mi.field.free_swap >=
mi.field.total_swap * swap_free_low_percentage / 100) {
// If the pressure is larger than downgrade_pressure lmk will not
// kill any process, since enough memory is available.
if (mem_pressure > downgrade_pressure) {
if (debug_process_killing) {
ALOGI("Ignore %s memory pressure", level_name[level]);
}
return;
} else if (level == VMPRESS_LEVEL_CRITICAL && mem_pressure > upgrade_pressure) {
if (debug_process_killing) {
ALOGI("Downgrade critical memory pressure");
}
// Downgrade event, since enough memory available.
level = downgrade_level(level);
}
}
do_kill:
if (low_ram_device) {
/* For Go devices kill only one task */
if (find_and_kill_process(level_oomadj[level]) == 0) {
if (debug_process_killing) {
ALOGI("Nothing to kill");
}
} else {
meminfo_log(&mi);
}
} else {
int pages_freed;
static struct timespec last_report_tm;
static unsigned long report_skip_count = 0;
if (!use_minfree_levels) {
/* If pressure level is less than critical and enough free swap then ignore */
if (level < VMPRESS_LEVEL_CRITICAL &&
mi.field.free_swap > low_pressure_mem.max_nr_free_pages) {
if (debug_process_killing) {
ALOGI("Ignoring pressure since %" PRId64
" swap pages are available ",
mi.field.free_swap);
}
return;
}
/* Free up enough memory to downgrate the memory pressure to low level */
if (mi.field.nr_free_pages >= low_pressure_mem.max_nr_free_pages) {
if (debug_process_killing) {
ALOGI("Ignoring pressure since more memory is "
"available (%" PRId64 ") than watermark (%" PRId64 ")",
mi.field.nr_free_pages, low_pressure_mem.max_nr_free_pages);
}
return;
}
min_score_adj = level_oomadj[level];
}
pages_freed = find_and_kill_process(min_score_adj);
if (pages_freed == 0) {
/* Rate limit kill reports when nothing was reclaimed */
if (get_time_diff_ms(&last_report_tm, &curr_tm) < FAIL_REPORT_RLIMIT_MS) {
report_skip_count++;
return;
}
} else {
/* If we killed anything, update the last killed timestamp. */
last_kill_tm = curr_tm;
}
/* Log meminfo whenever we kill or when report rate limit allows */
meminfo_log(&mi);
if (use_minfree_levels) {
ALOGI("Reclaimed %ldkB, cache(%ldkB) and "
"free(%" PRId64 "kB)-reserved(%" PRId64 "kB) below min(%ldkB) for oom_adj %d",
pages_freed * page_k,
other_file * page_k, mi.field.nr_free_pages * page_k,
zi.field.totalreserve_pages * page_k,
minfree * page_k, min_score_adj);
} else {
ALOGI("Reclaimed %ldkB at oom_adj %d",
pages_freed * page_k, min_score_adj);
}
if (report_skip_count > 0) {
ALOGI("Suppressed %lu failed kill reports", report_skip_count);
report_skip_count = 0;
}
last_report_tm = curr_tm;
}
}
static bool init_mp_common(enum vmpressure_level level) {
int mpfd;
int evfd;
int evctlfd;
char buf[256];
struct epoll_event epev;
int ret;
int level_idx = (int)level;
const char *levelstr = level_name[level_idx];
/* gid containing AID_SYSTEM required */
mpfd = open(MEMCG_SYSFS_PATH "memory.pressure_level", O_RDONLY | O_CLOEXEC);
if (mpfd < 0) {
ALOGI("No kernel memory.pressure_level support (errno=%d)", errno);
goto err_open_mpfd;
}
evctlfd = open(MEMCG_SYSFS_PATH "cgroup.event_control", O_WRONLY | O_CLOEXEC);
if (evctlfd < 0) {
ALOGI("No kernel memory cgroup event control (errno=%d)", errno);
goto err_open_evctlfd;
}
evfd = eventfd(0, EFD_NONBLOCK | EFD_CLOEXEC);
if (evfd < 0) {
ALOGE("eventfd failed for level %s; errno=%d", levelstr, errno);
goto err_eventfd;
}
ret = snprintf(buf, sizeof(buf), "%d %d %s", evfd, mpfd, levelstr);
if (ret >= (ssize_t)sizeof(buf)) {
ALOGE("cgroup.event_control line overflow for level %s", levelstr);
goto err;
}
ret = TEMP_FAILURE_RETRY(write(evctlfd, buf, strlen(buf) + 1));
if (ret == -1) {
ALOGE("cgroup.event_control write failed for level %s; errno=%d",
levelstr, errno);
goto err;
}
epev.events = EPOLLIN;
/* use data to store event level */
vmpressure_hinfo[level_idx].data = level_idx;
vmpressure_hinfo[level_idx].handler = mp_event_common;
epev.data.ptr = (void *)&vmpressure_hinfo[level_idx];
ret = epoll_ctl(epollfd, EPOLL_CTL_ADD, evfd, &epev);
if (ret == -1) {
ALOGE("epoll_ctl for level %s failed; errno=%d", levelstr, errno);
goto err;
}
maxevents++;
mpevfd[level] = evfd;
close(evctlfd);
return true;
err:
close(evfd);
err_eventfd:
close(evctlfd);
err_open_evctlfd:
close(mpfd);
err_open_mpfd:
return false;
}
static int init(void) {
struct epoll_event epev;
int i;
int ret;
page_k = sysconf(_SC_PAGESIZE);
if (page_k == -1)
page_k = PAGE_SIZE;
page_k /= 1024;
epollfd = epoll_create(MAX_EPOLL_EVENTS);
if (epollfd == -1) {
ALOGE("epoll_create failed (errno=%d)", errno);
return -1;
}
// mark data connections as not connected
for (int i = 0; i < MAX_DATA_CONN; i++) {
data_sock[i].sock = -1;
}
ctrl_sock.sock = android_get_control_socket("lmkd");
if (ctrl_sock.sock < 0) {
ALOGE("get lmkd control socket failed");
return -1;
}
ret = listen(ctrl_sock.sock, MAX_DATA_CONN);
if (ret < 0) {
ALOGE("lmkd control socket listen failed (errno=%d)", errno);
return -1;
}
epev.events = EPOLLIN;
ctrl_sock.handler_info.handler = ctrl_connect_handler;
epev.data.ptr = (void *)&(ctrl_sock.handler_info);
if (epoll_ctl(epollfd, EPOLL_CTL_ADD, ctrl_sock.sock, &epev) == -1) {
ALOGE("epoll_ctl for lmkd control socket failed (errno=%d)", errno);
return -1;
}
maxevents++;
has_inkernel_module = !access(INKERNEL_MINFREE_PATH, W_OK);
use_inkernel_interface = has_inkernel_module;
if (use_inkernel_interface) {
ALOGI("Using in-kernel low memory killer interface");
} else {
if (!init_mp_common(VMPRESS_LEVEL_LOW) ||
!init_mp_common(VMPRESS_LEVEL_MEDIUM) ||
!init_mp_common(VMPRESS_LEVEL_CRITICAL)) {
ALOGE("Kernel does not support memory pressure events or in-kernel low memory killer");
return -1;
}
}
for (i = 0; i <= ADJTOSLOT(OOM_SCORE_ADJ_MAX); i++) {
procadjslot_list[i].next = &procadjslot_list[i];
procadjslot_list[i].prev = &procadjslot_list[i];
}
memset(killcnt_idx, KILLCNT_INVALID_IDX, sizeof(killcnt_idx));
return 0;
}
static void mainloop(void) {
struct event_handler_info* handler_info;
struct epoll_event *evt;
while (1) {
struct epoll_event events[maxevents];
int nevents;
int i;
nevents = epoll_wait(epollfd, events, maxevents, -1);
if (nevents == -1) {
if (errno == EINTR)
continue;
ALOGE("epoll_wait failed (errno=%d)", errno);
continue;
}
/*
* First pass to see if any data socket connections were dropped.
* Dropped connection should be handled before any other events
* to deallocate data connection and correctly handle cases when
* connection gets dropped and reestablished in the same epoll cycle.
* In such cases it's essential to handle connection closures first.
*/
for (i = 0, evt = &events[0]; i < nevents; ++i, evt++) {
if ((evt->events & EPOLLHUP) && evt->data.ptr) {
ALOGI("lmkd data connection dropped");
handler_info = (struct event_handler_info*)evt->data.ptr;
ctrl_data_close(handler_info->data);
}
}
/* Second pass to handle all other events */
for (i = 0, evt = &events[0]; i < nevents; ++i, evt++) {
if (evt->events & EPOLLERR)
ALOGD("EPOLLERR on event #%d", i);
if (evt->events & EPOLLHUP) {
/* This case was handled in the first pass */
continue;
}
if (evt->data.ptr) {
handler_info = (struct event_handler_info*)evt->data.ptr;
handler_info->handler(handler_info->data, evt->events);
}
}
}
}
int main(int argc __unused, char **argv __unused) {
struct sched_param param = {
.sched_priority = 1,
};
/* By default disable low level vmpressure events */
level_oomadj[VMPRESS_LEVEL_LOW] =
property_get_int32("ro.lmk.low", OOM_SCORE_ADJ_MAX + 1);
level_oomadj[VMPRESS_LEVEL_MEDIUM] =
property_get_int32("ro.lmk.medium", 800);
level_oomadj[VMPRESS_LEVEL_CRITICAL] =
property_get_int32("ro.lmk.critical", 0);
debug_process_killing = property_get_bool("ro.lmk.debug", false);
/* By default disable upgrade/downgrade logic */
enable_pressure_upgrade =
property_get_bool("ro.lmk.critical_upgrade", false);
upgrade_pressure =
(int64_t)property_get_int32("ro.lmk.upgrade_pressure", 100);
downgrade_pressure =
(int64_t)property_get_int32("ro.lmk.downgrade_pressure", 100);
kill_heaviest_task =
property_get_bool("ro.lmk.kill_heaviest_task", false);
low_ram_device = property_get_bool("ro.config.low_ram", false);
kill_timeout_ms =
(unsigned long)property_get_int32("ro.lmk.kill_timeout_ms", 0);
use_minfree_levels =
property_get_bool("ro.lmk.use_minfree_levels", false);
per_app_memcg =
property_get_bool("ro.config.per_app_memcg", low_ram_device);
swap_free_low_percentage =
property_get_int32("ro.lmk.swap_free_low_percentage", 10);
ctx = create_android_logger(MEMINFO_LOG_TAG);
#ifdef LMKD_LOG_STATS
statslog_init(&log_ctx, &enable_stats_log);
#endif
if (!init()) {
if (!use_inkernel_interface) {
/*
* MCL_ONFAULT pins pages as they fault instead of loading
* everything immediately all at once. (Which would be bad,
* because as of this writing, we have a lot of mapped pages we
* never use.) Old kernels will see MCL_ONFAULT and fail with
* EINVAL; we ignore this failure.
*
* N.B. read the man page for mlockall. MCL_CURRENT | MCL_ONFAULT
* pins ⊆ MCL_CURRENT, converging to just MCL_CURRENT as we fault
* in pages.
*/
/* CAP_IPC_LOCK required */
if (mlockall(MCL_CURRENT | MCL_FUTURE | MCL_ONFAULT) && (errno != EINVAL)) {
ALOGW("mlockall failed %s", strerror(errno));
}
/* CAP_NICE required */
if (sched_setscheduler(0, SCHED_FIFO, &param)) {
ALOGW("set SCHED_FIFO failed %s", strerror(errno));
}
}
mainloop();
}
#ifdef LMKD_LOG_STATS
statslog_destroy(&log_ctx);
#endif
android_log_destroy(&ctx);
ALOGI("exiting");
return 0;
}
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