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Commit 0f100518 authored by Suren Baghdasaryan's avatar Suren Baghdasaryan
Browse files

lmkd: Introduce liblmkd_utils for communicating with lmkd process 



A number of tools and tests require communication with lmkd.
In order to avoid code duplication liblmkd_utils implements
functions commonly used when interacting with lmkd process.
Isolate communication protocol details into lmkd.h

Bug: 63631020

Change-Id: Id840983d55b7db60013d52dee0c3187943811822
Signed-off-by: default avatarSuren Baghdasaryan <surenb@google.com>
parent bd73476d

lmkd/Android.bp

+15 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ cc_binary { 
        "liblog",

        "libcutils",

    ],

    local_include_dirs: ["include"],

    cflags: ["-Werror"],



    init_rc: ["lmkd.rc"],
@@ -30,3 +31,17 @@ cc_library_shared { 
        "liblog",

    ],

}



cc_library_static {

    name: "liblmkd_utils",

    srcs: ["liblmkd_utils.c"],

    shared_libs: [

        "libcutils",

    ],

    export_include_dirs: ["include"],

    cppflags: [

        "-g",

        "-Wall",

        "-Werror",

    ]

}

lmkd/include/liblmkd_utils.h

0 → 100644
+54 −0
Original line number Diff line number Diff line 
/*

 *  Copyright 2018 Google, Inc

 *

 *  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.

 */



#ifndef _LIBLMKD_UTILS_H_

#define _LIBLMKD_UTILS_H_



#include <sys/cdefs.h>

#include <sys/types.h>



#include <lmkd.h>



__BEGIN_DECLS



/*

 * Connects to lmkd process and returns socket handle.

 * On success returns socket handle.

 * On error, -1 is returned, and errno is set appropriately.

 */

int lmkd_connect();



/*

 * Registers a process with lmkd and sets its oomadj score.

 * On success returns 0.

 * On error, -1 is returned.

 * In the case of error errno is set appropriately.

 */

int lmkd_register_proc(int sock, struct lmk_procprio *params);



/*

 * Creates memcg directory for given process.

 * On success returns 0.

 * -1 is returned if path creation failed.

 * -2 is returned if tasks file open operation failed.

 * -3 is returned if tasks file write operation failed.

 * In the case of error errno is set appropriately.

 */

int create_memcg(uid_t uid, pid_t pid);



__END_DECLS



#endif /* _LIBLMKD_UTILS_H_ */

lmkd/include/lmkd.h

0 → 100644
+147 −0
Original line number Diff line number Diff line 
/*

 *  Copyright 2018 Google, Inc

 *

 *  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.

 */



#ifndef _LMKD_H_

#define _LMKD_H_



#include <arpa/inet.h>

#include <sys/cdefs.h>

#include <sys/types.h>



__BEGIN_DECLS



/*

 * Supported LMKD commands

 */

enum lmk_cmd {

    LMK_TARGET = 0,  /* Associate minfree with oom_adj_score */

    LMK_PROCPRIO,    /* Register a process and set its oom_adj_score */

    LMK_PROCREMOVE,  /* Unregister a process */

};



/*

 * Max number of targets in LMK_TARGET command.

 */

#define MAX_TARGETS 6



/*

 * Max packet length in bytes.

 * Longest packet is LMK_TARGET followed by MAX_TARGETS

 * of minfree and oom_adj_score values

 */

#define CTRL_PACKET_MAX_SIZE (sizeof(int) * (MAX_TARGETS * 2 + 1))



/* LMKD packet - first int is lmk_cmd followed by payload */

typedef int LMKD_CTRL_PACKET[CTRL_PACKET_MAX_SIZE / sizeof(int)];



/* Get LMKD packet command */

inline enum lmk_cmd lmkd_pack_get_cmd(LMKD_CTRL_PACKET pack) {

    return (enum lmk_cmd)ntohl(pack[0]);

}



/* LMK_TARGET packet payload */

struct lmk_target {

    int minfree;

    int oom_adj_score;

};



/*

 * For LMK_TARGET packet get target_idx-th payload.

 * Warning: no checks performed, caller should ensure valid parameters.

 */

inline void lmkd_pack_get_target(LMKD_CTRL_PACKET packet,

                                 int target_idx, struct lmk_target *target) {

    target->minfree = ntohl(packet[target_idx * 2 + 1]);

    target->oom_adj_score = ntohl(packet[target_idx * 2 + 2]);

}



/*

 * Prepare LMK_TARGET packet and return packet size in bytes.

 * Warning: no checks performed, caller should ensure valid parameters.

 */

inline size_t lmkd_pack_set_target(LMKD_CTRL_PACKET packet,

                                   struct lmk_target *targets,

                                   size_t target_cnt) {

    int idx = 0;

    packet[idx++] = htonl(LMK_TARGET);

    while (target_cnt) {

        packet[idx++] = htonl(targets->minfree);

        packet[idx++] = htonl(targets->oom_adj_score);

        targets++;

        target_cnt--;

    }

    return idx * sizeof(int);

}



/* LMK_PROCPRIO packet payload */

struct lmk_procprio {

    pid_t pid;

    uid_t uid;

    int oomadj;

};



/*

 * For LMK_PROCPRIO packet get its payload.

 * Warning: no checks performed, caller should ensure valid parameters.

 */

inline void lmkd_pack_get_procprio(LMKD_CTRL_PACKET packet,

                                   struct lmk_procprio *params) {

    params->pid = (pid_t)ntohl(packet[1]);

    params->uid = (uid_t)ntohl(packet[2]);

    params->oomadj = ntohl(packet[3]);

}



/*

 * Prepare LMK_PROCPRIO packet and return packet size in bytes.

 * Warning: no checks performed, caller should ensure valid parameters.

 */

inline size_t lmkd_pack_set_procprio(LMKD_CTRL_PACKET packet,

                                   struct lmk_procprio *params) {

    packet[0] = htonl(LMK_PROCPRIO);

    packet[1] = htonl(params->pid);

    packet[2] = htonl(params->uid);

    packet[3] = htonl(params->oomadj);

    return 4 * sizeof(int);

}



/* LMK_PROCREMOVE packet payload */

struct lmk_procremove {

    pid_t pid;

};



/*

 * For LMK_PROCREMOVE packet get its payload.

 * Warning: no checks performed, caller should ensure valid parameters.

 */

inline void lmkd_pack_get_procremove(LMKD_CTRL_PACKET packet,

                                   struct lmk_procremove *params) {

    params->pid = (pid_t)ntohl(packet[1]);

}



/*

 * Prepare LMK_PROCREMOVE packet and return packet size in bytes.

 * Warning: no checks performed, caller should ensure valid parameters.

 */

inline size_t lmkd_pack_set_procremove(LMKD_CTRL_PACKET packet,

                                   struct lmk_procprio *params) {

    packet[0] = htonl(LMK_PROCREMOVE);

    packet[1] = htonl(params->pid);

    return 2 * sizeof(int);

}



__END_DECLS



#endif /* _LMKD_H_ */

lmkd/liblmkd_utils.c

0 → 100644
+76 −0
Original line number Diff line number Diff line 
/*

 *  Copyright 2018 Google, Inc

 *

 *  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.

 */



#include <errno.h>

#include <fcntl.h>

#include <sys/cdefs.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <stdio.h>

#include <unistd.h>



#include <liblmkd_utils.h>

#include <cutils/sockets.h>



int lmkd_connect() {

    return socket_local_client("lmkd",

                               ANDROID_SOCKET_NAMESPACE_RESERVED,

                               SOCK_SEQPACKET);

}



int lmkd_register_proc(int sock, struct lmk_procprio *params) {

    LMKD_CTRL_PACKET packet;

    size_t size;

    int ret;



    size = lmkd_pack_set_procprio(packet, params);

    ret = TEMP_FAILURE_RETRY(write(sock, packet, size));



    return (ret < 0) ? -1 : 0;

}



int create_memcg(uid_t uid, pid_t pid) {

    char buf[256];

    int tasks_file;

    int written;



    snprintf(buf, sizeof(buf), "/dev/memcg/apps/uid_%u", uid);

    if (mkdir(buf, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) < 0 &&

        errno != EEXIST) {

        return -1;

    }



    snprintf(buf, sizeof(buf), "/dev/memcg/apps/uid_%u/pid_%u", uid, pid);

    if (mkdir(buf, S_IRWXU | S_IRWXG | S_IROTH | S_IXOTH) < 0 &&

        errno != EEXIST) {

        return -1;

    }



    snprintf(buf, sizeof(buf), "/dev/memcg/apps/uid_%u/pid_%u/tasks", uid, pid);

    tasks_file = open(buf, O_WRONLY);

    if (tasks_file < 0) {

        return -2;

    }

    written = snprintf(buf, sizeof(buf), "%u", pid);

    if (__predict_false(written >= (int)sizeof(buf))) {

        written = sizeof(buf) - 1;

    }

    written = TEMP_FAILURE_RETRY(write(tasks_file, buf, written));

    close(tasks_file);



    return (written < 0) ? -3 : 0;

}

lmkd/lmkd.c

+51 −49
Original line number Diff line number Diff line
@@ -16,7 +16,6 @@ 


#define LOG_TAG "lowmemorykiller"



#include <arpa/inet.h>

#include <errno.h>

#include <inttypes.h>

#include <sched.h>
@@ -34,6 +33,7 @@ 


#include <cutils/properties.h>

#include <cutils/sockets.h>

#include <lmkd.h>

#include <log/log.h>



/*
@@ -71,19 +71,6 @@ 
#define ARRAY_SIZE(x)   (sizeof(x) / sizeof(*(x)))

#define EIGHT_MEGA (1 << 23)



enum lmk_cmd {

    LMK_TARGET,

    LMK_PROCPRIO,

    LMK_PROCREMOVE,

};



#define MAX_TARGETS 6

/*

 * longest is LMK_TARGET followed by MAX_TARGETS each minfree and minkillprio

 * values

 */

#define CTRL_PACKET_MAX (sizeof(int) * (MAX_TARGETS * 2 + 1))



/* default to old in-kernel interface if no memory pressure events */

static int use_inkernel_interface = 1;

static bool has_inkernel_module;
@@ -300,45 +287,49 @@ static void writefilestring(const char *path, char *s) { 
    close(fd);

}



static void cmd_procprio(int pid, int uid, int oomadj) {

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;



    lmkd_pack_get_procprio(packet, &params);



    if (oomadj < OOM_SCORE_ADJ_MIN || oomadj > OOM_SCORE_ADJ_MAX) {

        ALOGE("Invalid PROCPRIO oomadj argument %d", oomadj);

    if (params.oomadj < OOM_SCORE_ADJ_MIN ||

        params.oomadj > OOM_SCORE_ADJ_MAX) {

        ALOGE("Invalid PROCPRIO oomadj argument %d", params.oomadj);

        return;

    }



    snprintf(path, sizeof(path), "/proc/%d/oom_score_adj", pid);

    snprintf(val, sizeof(val), "%d", oomadj);

    snprintf(path, sizeof(path), "/proc/%d/oom_score_adj", params.pid);

    snprintf(val, sizeof(val), "%d", params.oomadj);

    writefilestring(path, val);



    if (use_inkernel_interface)

        return;



    if (oomadj >= 900) {

    if (params.oomadj >= 900) {

        soft_limit_mult = 0;

    } else if (oomadj >= 800) {

    } else if (params.oomadj >= 800) {

        soft_limit_mult = 0;

    } else if (oomadj >= 700) {

    } else if (params.oomadj >= 700) {

        soft_limit_mult = 0;

    } else if (oomadj >= 600) {

    } else if (params.oomadj >= 600) {

        // Launcher should be perceptible, don't kill it.

        oomadj = 200;

        params.oomadj = 200;

        soft_limit_mult = 1;

    } else if (oomadj >= 500) {

    } else if (params.oomadj >= 500) {

        soft_limit_mult = 0;

    } else if (oomadj >= 400) {

    } else if (params.oomadj >= 400) {

        soft_limit_mult = 0;

    } else if (oomadj >= 300) {

    } else if (params.oomadj >= 300) {

        soft_limit_mult = 1;

    } else if (oomadj >= 200) {

    } else if (params.oomadj >= 200) {

        soft_limit_mult = 2;

    } else if (oomadj >= 100) {

    } else if (params.oomadj >= 100) {

        soft_limit_mult = 10;

    } else if (oomadj >=   0) {

    } else if (params.oomadj >=   0) {

        soft_limit_mult = 20;

    } else {

        // Persistent processes will have a large
@@ -346,11 +337,13 @@ static void cmd_procprio(int pid, int uid, int oomadj) { 
        soft_limit_mult = 64;

    }



    snprintf(path, sizeof(path), "/dev/memcg/apps/uid_%d/pid_%d/memory.soft_limit_in_bytes", uid, pid);

    snprintf(path, sizeof(path),

             "/dev/memcg/apps/uid_%d/pid_%d/memory.soft_limit_in_bytes",

             params.uid, params.pid);

    snprintf(val, sizeof(val), "%d", soft_limit_mult * EIGHT_MEGA);

    writefilestring(path, val);



    procp = pid_lookup(pid);

    procp = pid_lookup(params.pid);

    if (!procp) {

            procp = malloc(sizeof(struct proc));

            if (!procp) {
@@ -358,33 +351,38 @@ static void cmd_procprio(int pid, int uid, int oomadj) { 
                return;

            }



            procp->pid = pid;

            procp->uid = uid;

            procp->oomadj = oomadj;

            procp->pid = params.pid;

            procp->uid = params.uid;

            procp->oomadj = params.oomadj;

            proc_insert(procp);

    } else {

        proc_unslot(procp);

        procp->oomadj = oomadj;

        procp->oomadj = params.oomadj;

        proc_slot(procp);

    }

}



static void cmd_procremove(int pid) {

static void cmd_procremove(LMKD_CTRL_PACKET packet) {

    struct lmk_procremove params;



    if (use_inkernel_interface)

        return;



    pid_remove(pid);

    lmkd_pack_get_procremove(packet, &params);

    pid_remove(params.pid);

}



static void cmd_target(int ntargets, int *params) {

static void cmd_target(int ntargets, LMKD_CTRL_PACKET packet) {

    int i;

    struct lmk_target target;



    if (ntargets > (int)ARRAY_SIZE(lowmem_adj))

        return;



    for (i = 0; i < ntargets; i++) {

        lowmem_minfree[i] = ntohl(*params++);

        lowmem_adj[i] = ntohl(*params++);

        lmkd_pack_get_target(packet, i, &target);

        lowmem_minfree[i] = target.minfree;

        lowmem_adj[i] = target.oom_adj_score;

    }



    lowmem_targets_size = ntargets;
@@ -445,38 +443,42 @@ static int ctrl_data_read(int dsock_idx, char *buf, size_t bufsz) { 
}



static void ctrl_command_handler(int dsock_idx) {

    int ibuf[CTRL_PACKET_MAX / sizeof(int)];

    LMKD_CTRL_PACKET packet;

    int len;

    int cmd = -1;

    enum lmk_cmd cmd;

    int nargs;

    int targets;



    len = ctrl_data_read(dsock_idx, (char *)ibuf, CTRL_PACKET_MAX);

    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;



    cmd = ntohl(ibuf[0]);



    switch(cmd) {

    case LMK_TARGET:

        targets = nargs / 2;

        if (nargs & 0x1 || targets > (int)ARRAY_SIZE(lowmem_adj))

            goto wronglen;

        cmd_target(targets, &ibuf[1]);

        cmd_target(targets, packet);

        break;

    case LMK_PROCPRIO:

        if (nargs != 3)

            goto wronglen;

        cmd_procprio(ntohl(ibuf[1]), ntohl(ibuf[2]), ntohl(ibuf[3]));

        cmd_procprio(packet);

        break;

    case LMK_PROCREMOVE:

        if (nargs != 1)

            goto wronglen;

        cmd_procremove(ntohl(ibuf[1]));

        cmd_procremove(packet);

        break;

    default:

        ALOGE("Received unknown command code %d", cmd);