Debugfs collector (#15017)

Co-authored-by: Fotis Voutsas <fotis@netdata.cloud> Co-authored-by: Austin S. Hemmelgarn <ahferroin7@gmail.com> Co-authored-by: ilyam8 <ilya@netdata.cloud>
2025-04-10 16:17:36 +00:00 · 2023-05-15 16:06:26 +00:00 · 2023-05-15 16:06:26 +00:00 · 588096c6b6
commit 588096c6b6
parent bdc40c318a
24 changed files with 1039 additions and 4 deletions
--- a/.github/labeler.yml
+++ b/.github/labeler.yml
@ -78,6 +78,10 @@ collectors/cups:
  - collectors/cups.plugin/*
  - collectors/cups.plugin/**/*

+collectors/debugfs:
+  - collectors/debugfs.plugin/*
+  - collectors/debugfs.plugin/**/*
+
 collectors/diskspace:
  - collectors/diskspace.plugin/*
  - collectors/diskspace.plugin/**/*
--- a/.gitignore
+++ b/.gitignore
@ -74,6 +74,9 @@ collectors/ebpf.plugin/reset_netdata_trace.sh
 !ebpf.plugin/
 collectors/ebpf.plugin/includes/

+debugfs.plugin
+!debugfs.plugin/
+
 # protoc generated files
 *.pb.cc
 *.pb.h
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@ -507,6 +507,13 @@ target_include_directories(libnetdata BEFORE PUBLIC ${GENERATED_CONFIG_H_DIR})
 set(APPS_PLUGIN_FILES
        collectors/apps.plugin/apps_plugin.c)

+set(DEBUGFS_PLUGIN_FILES
+        collectors/debugfs.plugin/debugfs_plugin.c
+        collectors/debugfs.plugin/debugfs_plugin.h
+        collectors/debugfs.plugin/debugfs_extfrag.c
+        collectors/debugfs.plugin/debugfs_zswap.c
+        )
+
 set(FREEBSD_PLUGIN_FILES
        collectors/freebsd.plugin/plugin_freebsd.c
        collectors/freebsd.plugin/plugin_freebsd.h
@ -1363,6 +1370,21 @@ target_include_directories(netdatacli BEFORE PUBLIC ${GENERATED_CONFIG_H_DIR})
 target_compile_options(netdatacli PUBLIC ${NETDATA_COMMON_CFLAGS})


+# -----------------------------------------------------------------------------
+# debugfs.plugin
+
+IF(ENABLE_PLUGIN_DEBUGFS)
+    message(STATUS "debugfs.plugin: enabled")
+    add_executable(debugfs.plugin ${GENERATED_CONFIG_H} ${DEBUGFS_PLUGIN_FILES})
+    target_link_libraries (debugfs.plugin libnetdata ${NETDATA_COMMON_LIBRARIES} ${CAP_LIBRARIES})
+    target_include_directories(debugfs.plugin PUBLIC ${NETDATA_COMMON_INCLUDE_DIRS} ${CAP_INCLUDE_DIRS})
+    target_include_directories(debugfs.plugin BEFORE PUBLIC ${GENERATED_CONFIG_H_DIR})
+    target_compile_options(debugfs.plugin PUBLIC ${NETDATA_COMMON_CFLAGS} ${CAP_CFLAGS_OTHER})
+ELSE()
+    message(STATUS "debugfs.plugin: disabled")
+ENDIF()
+
+
 # -----------------------------------------------------------------------------
 # apps.plugin

--- a/Makefile.am
+++ b/Makefile.am
@ -212,6 +212,14 @@ APPS_PLUGIN_FILES = \
    $(LIBNETDATA_FILES) \
    $(NULL)

+DEBUGFS_PLUGIN_FILES = \
+    collectors/debugfs.plugin/debugfs_plugin.c \
+    collectors/debugfs.plugin/debugfs_plugin.h \
+    collectors/debugfs.plugin/debugfs_extfrag.c \
+    collectors/debugfs.plugin/debugfs_zswap.c \
+    $(LIBNETDATA_FILES) \
+    $(NULL)
+
 FREEBSD_PLUGIN_FILES = \
    collectors/freebsd.plugin/plugin_freebsd.c \
    collectors/freebsd.plugin/plugin_freebsd.h \
@ -1168,6 +1176,15 @@ if ENABLE_PLUGIN_APPS
        $(NULL)
 endif

+if ENABLE_PLUGIN_DEBUGFS
+    plugins_PROGRAMS += debugfs.plugin
+    debugfs_plugin_SOURCES = $(DEBUGFS_PLUGIN_FILES)
+    debugfs_plugin_LDADD = \
+        $(NETDATA_COMMON_LIBS) \
+        $(OPTIONAL_LIBCAP_LIBS) \
+        $(NULL)
+endif
+
 if ENABLE_PLUGIN_CGROUP_NETWORK
    plugins_PROGRAMS += cgroup-network
    cgroup_network_SOURCES = $(CGROUP_NETWORK_FILES)
--- a/collectors/Makefile.am
+++ b/collectors/Makefile.am
@ -8,6 +8,7 @@ SUBDIRS = \
    cgroups.plugin \
    charts.d.plugin \
    cups.plugin \
+    debugfs.plugin \
    diskspace.plugin \
    timex.plugin \
    ioping.plugin \
--- a/collectors/all.h
+++ b/collectors/all.h
@ -24,8 +24,17 @@
 #define NETDATA_CHART_PRIO_SYSTEM_PGPGIO                151
 #define NETDATA_CHART_PRIO_SYSTEM_RAM                   200
 #define NETDATA_CHART_PRIO_SYSTEM_SWAP                  201
+#define NETDATA_CHART_PRIO_SYSTEM_SWAP_CALLS            202
 #define NETDATA_CHART_PRIO_SYSTEM_SWAPIO                250
 #define NETDATA_CHART_PRIO_SYSTEM_ZSWAPIO               300
+#define NETDATA_CHART_PRIO_SYSTEM_ZSWAP_COMPRESS_RATIO  301
+#define NETDATA_CHART_PRIO_SYSTEM_ZSWAP_POOL_TOT_SIZE   302
+#define NETDATA_CHART_PRIO_SYSTEM_ZSWAP_STORED_PAGE     303
+#define NETDATA_CHART_PRIO_SYSTEM_ZSWAP_REJECTS         304
+#define NETDATA_CHART_PRIO_SYSTEM_ZSWAP_POOL_LIM_HIT    305
+#define NETDATA_CHART_PRIO_SYSTEM_ZSWAP_WRT_BACK_PAGES  306
+#define NETDATA_CHART_PRIO_SYSTEM_ZSWAP_SAME_FILL_PAGE  307
+#define NETDATA_CHART_PRIO_SYSTEM_ZSWAP_DUPP_ENTRY      308
 #define NETDATA_CHART_PRIO_SYSTEM_NET                   500
 #define NETDATA_CHART_PRIO_SYSTEM_IPV4                  500 // freebsd only
 #define NETDATA_CHART_PRIO_SYSTEM_IP                    501
@ -103,6 +112,7 @@
 #define NETDATA_CHART_PRIO_MEM_ZRAM_SAVINGS           1601
 #define NETDATA_CHART_PRIO_MEM_ZRAM_RATIO             1602
 #define NETDATA_CHART_PRIO_MEM_ZRAM_EFFICIENCY        1603
+#define NETDATA_CHART_PRIO_MEM_FRAGMENTATION          1700

 // Disks

--- a/collectors/apps.plugin/apps_groups.conf
+++ b/collectors/apps.plugin/apps_groups.conf
@ -89,6 +89,7 @@ ioping: ioping
 go.d.plugin: *go.d.plugin*
 slabinfo.plugin: slabinfo.plugin
 ebpf.plugin: *ebpf.plugin*
+debugfs.plugin: *debugfs.plugin*

 # agent-service-discovery
 agent_sd: agent_sd
--- a/collectors/debugfs.plugin/Makefile.am
+++ b/collectors/debugfs.plugin/Makefile.am
@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+AUTOMAKE_OPTIONS = subdir-objects
+MAINTAINERCLEANFILES = $(srcdir)/Makefile.in
+
+dist_noinst_DATA = \
+    README.md \
+    $(NULL)
+
--- a/collectors/debugfs.plugin/README.md
+++ b/collectors/debugfs.plugin/README.md
@ -0,0 +1,65 @@
+# OS provided metrics (debugfs.plugin)
+
+`debugfs.plugin` gathers metrics from the `/sys/kernel/debug` folder on Linux
+systems. [Debugfs](https://docs.kernel.org/filesystems/debugfs.html) exists as an easy way for kernel developers to
+make information available to user space.
+
+This plugin
+is [external](https://github.com/netdata/netdata/tree/master/collectors#collector-architecture-and-terminology),
+the netdata daemon spawns it as a long-running independent process.
+
+In detail, it collects metrics from:
+
+- `/sys/kernel/debug/extfrag` (Memory fragmentation index for each order and zone).
+- `/sys/kernel/debug/zswap` ([Zswap](https://www.kernel.org/doc/Documentation/vm/zswap.txt) performance statistics).
+
+## Prerequisites
+
+### Permissions
+
+> No user action required.
+
+The debugfs root directory is accessible only to the root user by default. Netdata
+uses [Linux Capabilities](https://man7.org/linux/man-pages/man7/capabilities.7.html) to give the plugin access
+to debugfs. `CAP_DAC_READ_SEARCH` is added automatically during installation. This capability allows bypassing file read
+permission checks and directory read and execute permission checks. If file capabilities are not usable, then the plugin is instead installed with the SUID bit set in permissions so that it runs as root.
+
+## Metrics
+
+| Metric                              |   Scope   |                                       Dimensions                                        |    Units     |  Labels   |
+|-------------------------------------|:---------:|:---------------------------------------------------------------------------------------:|:------------:|:---------:|
+| mem.fragmentation_index_dma         | numa node | order0, order1, order2, order3, order4, order5, order6, order7, order8, order9, order10 |    index     | numa_node |
+| mem.fragmentation_index_dma32       | numa node | order0, order1, order2, order3, order4, order5, order6, order7, order8, order9, order10 |    index     | numa_node |
+| mem.fragmentation_index_normal      | numa node | order0, order1, order2, order3, order4, order5, order6, order7, order8, order9, order10 |    index     | numa_node |
+| system.zswap_pool_compression_ratio |           |                                    compression_ratio                                    |    ratio     |           |
+| system.zswap_pool_compressed_size   |           |                                     compressed_size                                     |    bytes     |           |
+| system.zswap_pool_raw_size          |           |                                    uncompressed_size                                    |    bytes     |           |
+| system.zswap_rejections             |           |                 compress_poor, kmemcache_fail, alloc_fail, reclaim_fail                 | rejections/s |           |
+| system.zswap_pool_limit_hit         |           |                                          limit                                          |   events/s   |           |
+| system.zswap_written_back_raw_bytes |           |                                      written_back                                       |   bytes/s    |           |
+| system.zswap_same_filled_raw_size   |           |                                       same_filled                                       |    bytes     |           |
+| system.zswap_duplicate_entry        |           |                                         entries                                         |  entries/s   |           |
+
+## Troubleshooting
+
+To troubleshoot issues with the collector, run the `debugfs.plugin` in the terminal. The output
+should give you clues as to why the collector isn't working.
+
+- Navigate to the `plugins.d` directory, usually at `/usr/libexec/netdata/plugins.d/`. If that's not the case on
+  your system, open `netdata.conf` and look for the `plugins` setting under `[directories]`.
+
+  ```bash
+  cd /usr/libexec/netdata/plugins.d/
+  ```
+
+- Switch to the `netdata` user.
+
+  ```bash
+  sudo -u netdata -s
+  ```
+
+- Run the `debugfs.plugin` to debug the collector:
+
+  ```bash
+  ./debugfs.plugin
+  ```
--- a/collectors/debugfs.plugin/debugfs_extfrag.c
+++ b/collectors/debugfs.plugin/debugfs_extfrag.c
@ -0,0 +1,123 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "debugfs_plugin.h"
+
+#define NETDATA_ORDER_FRAGMENTATION 11
+
+static char *orders[NETDATA_ORDER_FRAGMENTATION] = { "order0", "order1", "order2", "order3", "order4",
+                                                    "order5", "order6", "order7", "order8", "order9",
+                                                    "order10"
+};
+
+static struct netdata_extrafrag {
+    char *node_zone;
+    uint32_t hash;
+
+    char *id;
+
+    collected_number orders[NETDATA_ORDER_FRAGMENTATION];
+
+    struct netdata_extrafrag *next;
+} *netdata_extrafrags_root = NULL;
+
+static struct netdata_extrafrag *find_or_create_extrafrag(const char *name)
+{
+    struct netdata_extrafrag *extrafrag;
+    uint32_t hash = simple_hash(name);
+
+    // search it, from beginning to the end
+    for (extrafrag = netdata_extrafrags_root ; extrafrag ; extrafrag = extrafrag->next) {
+        if (unlikely(hash == extrafrag->hash && !strcmp(name, extrafrag->node_zone))) {
+            return extrafrag;
+        }
+    }
+
+    extrafrag = callocz(1, sizeof(struct netdata_extrafrag));
+    extrafrag->node_zone = strdupz(name);
+    extrafrag->hash = hash;
+
+    if (netdata_extrafrags_root) {
+        struct netdata_extrafrag *last_node;
+        for (last_node = netdata_extrafrags_root; last_node->next ; last_node = last_node->next);
+
+        last_node->next = extrafrag;
+    } else
+        netdata_extrafrags_root = extrafrag;
+
+
+    return extrafrag;
+}
+
+static void extfrag_send_chart(char *chart_id, collected_number *values)
+{
+    int i;
+    fprintf(stdout, "BEGIN mem.fragmentation_index_%s\n", chart_id);
+    for (i = 0; i < NETDATA_ORDER_FRAGMENTATION; i++) {
+        fprintf(stdout, "SET %s = %lld\n", orders[i], values[i]);
+    }
+    fprintf(stdout, "END\n");
+    fflush(stdout);
+}
+
+int do_debugfs_extfrag(int update_every, const char *name) {
+    static procfile *ff = NULL;
+    static int chart_order = NETDATA_CHART_PRIO_MEM_FRAGMENTATION;
+
+    if (unlikely(!ff)) {
+        char filename[FILENAME_MAX + 1];
+        snprintfz(filename,
+                  FILENAME_MAX,
+                  "%s%s",
+                  netdata_configured_host_prefix,
+                  "/sys/kernel/debug/extfrag/extfrag_index");
+
+        ff = procfile_open(filename, " \t,", PROCFILE_FLAG_DEFAULT);
+        if (unlikely(!ff)) return 1;
+    }
+
+    ff = procfile_readall(ff);
+    if (unlikely(!ff)) return 1;
+
+    size_t l, i, j, lines = procfile_lines(ff);
+    for (l = 0; l < lines; l++) {
+        char chart_id[64];
+        char zone_lowercase[32];
+        if (unlikely(procfile_linewords(ff, l) < 15)) continue;
+        char *zone = procfile_lineword(ff, l, 3);
+        strncpyz(zone_lowercase, zone, 31);
+        debugfs2lower(zone_lowercase);
+
+        char *id = procfile_lineword(ff, l, 1);
+        snprintfz(chart_id, 63, "node_%s_%s", id, zone_lowercase);
+        debugfs2lower(chart_id);
+
+        struct netdata_extrafrag *extrafrag = find_or_create_extrafrag(chart_id);
+        collected_number *line_orders = extrafrag->orders;
+        for (i = 4, j = 0 ; i < 15; i++, j++) {
+            NETDATA_DOUBLE value = str2ndd(procfile_lineword(ff, l, i), NULL);
+            line_orders[j] = (collected_number) (value * 1000.0);
+        }
+
+        if (unlikely(!extrafrag->id)) {
+            extrafrag->id = extrafrag->node_zone;
+            fprintf(
+                stdout,
+                "CHART mem.fragmentation_index_%s '' 'Memory fragmentation index for each order' 'index' 'fragmentation' 'mem.fragmentation_index_%s' 'line' %d %d '' 'debugfs.plugin' '%s'\n",
+                extrafrag->node_zone,
+                zone_lowercase,
+                chart_order++, // FIXME: the same zones must have the same order
+                update_every,
+                name);
+            for (i = 0; i < NETDATA_ORDER_FRAGMENTATION; i++) {
+                fprintf(stdout, "DIMENSION '%s' '%s' absolute 1 1000 ''\n", orders[i], orders[i]);
+            }
+            fprintf(stdout,
+                    "CLABEL 'numa_node' 'node%s' 1\n"
+                    "CLABEL_COMMIT\n",
+                    id);
+        }
+        extfrag_send_chart(chart_id, line_orders);
+    }
+
+    return 0;
+}
--- a/collectors/debugfs.plugin/debugfs_plugin.c
+++ b/collectors/debugfs.plugin/debugfs_plugin.c
@ -0,0 +1,244 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "debugfs_plugin.h"
+#include "libnetdata/required_dummies.h"
+
+static char *user_config_dir = CONFIG_DIR;
+static char *stock_config_dir = LIBCONFIG_DIR;
+
+static int update_every = 1;
+
+static struct debugfs_module {
+    const char *name;
+
+    int enabled;
+
+    int (*func)(int update_every, const char *name);
+}  debugfs_modules[] = {
+    // Memory Fragmentation
+    { .name = "/sys/kernel/debug/extfrag", .enabled = CONFIG_BOOLEAN_YES,
+      .func = do_debugfs_extfrag},
+    { .name = "/sys/kernel/debug/zswap", .enabled = CONFIG_BOOLEAN_YES,
+      .func = do_debugfs_zswap},
+
+    // The terminator
+    { .name = NULL, .enabled = CONFIG_BOOLEAN_NO, .func = NULL}
+};
+
+#ifdef HAVE_CAPABILITY
+static int debugfs_check_capabilities()
+{
+    cap_t caps = cap_get_proc();
+    if (!caps) {
+        error("Cannot get current capabilities.");
+        return 0;
+    }
+
+    int ret = 1;
+    cap_flag_value_t cfv = CAP_CLEAR;
+    if (cap_get_flag(caps, CAP_DAC_READ_SEARCH, CAP_EFFECTIVE, &cfv) == -1) {
+        error("Cannot find if CAP_DAC_READ_SEARCH is effective.");
+        ret = 0;
+    } else {
+        if (cfv != CAP_SET) {
+            error("debugfs.plugin should run with CAP_DAC_READ_SEARCH.");
+            ret = 0;
+        }
+    }
+    cap_free(caps);
+
+    return ret;
+}
+#else
+static int debugfs_check_capabilities()
+{
+    return 0;
+}
+#endif
+
+// TODO: This is a function used by 3 different collector, we should do it global (next PR)
+static int debugfs_am_i_running_as_root()
+{
+    uid_t uid = getuid(), euid = geteuid();
+
+    if (uid == 0 || euid == 0) {
+        return 1;
+    }
+
+    return 0;
+}
+
+void debugfs2lower(char *name)
+{
+    while (*name) {
+        *name = tolower(*name);
+        name++;
+    }
+}
+
+// Consiidering our goal to redce binaries, I preferred to copy function, instead to force link with unecessary libs
+const char *debugfs_rrdset_type_name(RRDSET_TYPE chart_type) {
+    switch(chart_type) {
+        case RRDSET_TYPE_LINE:
+        default:
+            return RRDSET_TYPE_LINE_NAME;
+
+        case RRDSET_TYPE_AREA:
+            return RRDSET_TYPE_AREA_NAME;
+
+        case RRDSET_TYPE_STACKED:
+            return RRDSET_TYPE_STACKED_NAME;
+    }
+}
+
+const char *debugfs_rrd_algorithm_name(RRD_ALGORITHM algorithm) {
+    switch(algorithm) {
+        case RRD_ALGORITHM_ABSOLUTE:
+        default:
+            return RRD_ALGORITHM_ABSOLUTE_NAME;
+
+        case RRD_ALGORITHM_INCREMENTAL:
+            return RRD_ALGORITHM_INCREMENTAL_NAME;
+
+        case RRD_ALGORITHM_PCENT_OVER_ROW_TOTAL:
+            return RRD_ALGORITHM_PCENT_OVER_ROW_TOTAL_NAME;
+
+        case RRD_ALGORITHM_PCENT_OVER_DIFF_TOTAL:
+            return RRD_ALGORITHM_PCENT_OVER_DIFF_TOTAL_NAME;
+    }
+}
+
+int debugfs_check_sys_permission() {
+    int ret = 0;
+
+    char filename[FILENAME_MAX + 1];
+
+    snprintfz(filename, FILENAME_MAX, "%s/sys/kernel/debug/extfrag/extfrag_index", netdata_configured_host_prefix);
+
+    procfile *ff = procfile_open(filename, NULL, PROCFILE_FLAG_NO_ERROR_ON_FILE_IO);
+    if(!ff) goto dcsp_cleanup;
+
+    ff = procfile_readall(ff);
+    if(!ff) goto dcsp_cleanup;
+
+    ret = 1;
+
+dcsp_cleanup:
+    if (!ret)
+        perror("Cannot open /sys/kernel/debug/extfrag/extfrag_index file");
+    procfile_close(ff);
+    return ret;
+}
+
+static void debugfs_parse_args(int argc, char **argv)
+{
+    int i, freq = 0;
+    for(i = 1; i < argc; i++) {
+        if(!freq) {
+            int n = (int)str2l(argv[i]);
+            if(n > 0) {
+                freq = n;
+                continue;
+            }
+        }
+
+        if(strcmp("test-permissions", argv[i]) == 0 || strcmp("-t", argv[i]) == 0) {
+            if(!debugfs_check_sys_permission()) {
+                exit(2);
+            }
+            printf("OK\n");
+            exit(0);
+        }
+    }
+
+    if(freq > 0) update_every = freq;
+}
+
+int main(int argc, char **argv)
+{
+    // debug_flags = D_PROCFILE;
+    stderror = stderr;
+
+    // set the name for logging
+    program_name = "debugfs.plugin";
+
+    // disable syslog for debugfs.plugin
+    error_log_syslog = 0;
+
+    netdata_configured_host_prefix = getenv("NETDATA_HOST_PREFIX");
+    if (verify_netdata_host_prefix() == -1)
+        exit(1);
+
+    user_config_dir = getenv("NETDATA_USER_CONFIG_DIR");
+    if (user_config_dir == NULL) {
+        user_config_dir = CONFIG_DIR;
+    }
+
+    stock_config_dir = getenv("NETDATA_STOCK_CONFIG_DIR");
+    if (stock_config_dir == NULL) {
+        // info("NETDATA_CONFIG_DIR is not passed from netdata");
+        stock_config_dir = LIBCONFIG_DIR;
+    }
+
+    // FIXME: should first check if /sys/kernel/debug is mounted
+
+    // FIXME: remove debugfs_check_sys_permission() after https://github.com/netdata/netdata/issues/15048 is fixed
+    if (!debugfs_check_capabilities() && !debugfs_am_i_running_as_root() && !debugfs_check_sys_permission()) {
+        uid_t uid = getuid(), euid = geteuid();
+#ifdef HAVE_CAPABILITY
+        error(
+            "debugfs.plugin should either run as root (now running with uid %u, euid %u) or have special capabilities. "
+            "Without these, debugfs.plugin cannot access /sys/kernel/debug. "
+            "To enable capabilities run: sudo setcap cap_dac_read_search,cap_sys_ptrace+ep %s; "
+            "To enable setuid to root run: sudo chown root:netdata %s; sudo chmod 4750 %s; ",
+            uid,
+            euid,
+            argv[0],
+            argv[0],
+            argv[0]);
+#else
+        error(
+            "debugfs.plugin should either run as root (now running with uid %u, euid %u) or have special capabilities. "
+            "Without these, debugfs.plugin cannot access /sys/kernel/debug."
+            "Your system does not support capabilities. "
+            "To enable setuid to root run: sudo chown root:netdata %s; sudo chmod 4750 %s; ",
+            uid,
+            euid,
+            argv[0],
+            argv[0]);
+#endif
+        exit(1);
+    }
+
+    // if (!debugfs_check_sys_permission()) {
+    //     exit(2);
+    // }
+
+    debugfs_parse_args(argc, argv);
+
+    size_t iteration;
+    usec_t step = update_every * USEC_PER_SEC;
+    heartbeat_t hb;
+    heartbeat_init(&hb);
+
+    for (iteration = 0; iteration < 86400; iteration++) {
+        heartbeat_next(&hb, step);
+        int enabled = 0;
+
+        for (int i = 0; debugfs_modules[i].name; i++) {
+            struct debugfs_module *pm = &debugfs_modules[i];
+            if (unlikely(!pm->enabled))
+                continue;
+
+            pm->enabled = !pm->func(update_every, pm->name);
+            if (likely(pm->enabled))
+                enabled++;
+        }
+        if (!enabled) {
+            info("all modules are disabled, exiting...");
+            return 1;
+        }
+    }
+
+    return 0;
+}
--- a/collectors/debugfs.plugin/debugfs_plugin.h
+++ b/collectors/debugfs.plugin/debugfs_plugin.h
@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_DEBUGFS_PLUGIN_H
+#define NETDATA_DEBUGFS_PLUGIN_H 1
+
+#include "libnetdata/libnetdata.h"
+#include "collectors/all.h"
+#include "database/rrd.h"
+
+int do_debugfs_extfrag(int update_every, const char *name);
+int do_debugfs_zswap(int update_every, const char *name);
+void debugfs2lower(char *name);
+const char *debugfs_rrdset_type_name(RRDSET_TYPE chart_type);
+const char *debugfs_rrd_algorithm_name(RRD_ALGORITHM algorithm);
+
+#endif // NETDATA_DEBUGFS_PLUGIN_H
--- a/collectors/debugfs.plugin/debugfs_zswap.c
+++ b/collectors/debugfs.plugin/debugfs_zswap.c
@ -0,0 +1,432 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "debugfs_plugin.h"
+
+static long system_page_size = 4096;
+
+static collected_number pages_to_bytes(collected_number value)
+{
+    return value * system_page_size;
+}
+
+struct netdata_zswap_metric {
+    const char *filename;
+
+    const char *chart_id;
+    const char *title;
+    const char *units;
+    RRDSET_TYPE charttype;
+    int prio;
+    const char *dimension;
+    RRD_ALGORITHM algorithm;
+    int divisor;
+
+    int enabled;
+    int chart_created;
+
+    collected_number value;
+    collected_number (*convertv)(collected_number v);
+};
+
+static struct netdata_zswap_metric zswap_calculated_metrics[] = {
+    {.filename = "",
+     .chart_id = "pool_compression_ratio",
+     .dimension = "compression_ratio",
+     .units = "ratio",
+     .title = "Zswap compression ratio",
+     .algorithm = RRD_ALGORITHM_ABSOLUTE,
+     .charttype = RRDSET_TYPE_LINE,
+     .enabled = CONFIG_BOOLEAN_YES,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = NETDATA_CHART_PRIO_SYSTEM_ZSWAP_COMPRESS_RATIO,
+     .divisor = 100,
+     .convertv = NULL,
+     .value = -1},
+};
+
+enum netdata_zswap_calculated {
+    NETDATA_ZSWAP_COMPRESSION_RATIO_CHART,
+};
+
+enum netdata_zwap_independent {
+    NETDATA_ZSWAP_POOL_TOTAL_SIZE,
+    NETDATA_ZSWAP_STORED_PAGES,
+    NETDATA_ZSWAP_POOL_LIMIT_HIT,
+    NETDATA_ZSWAP_WRITTEN_BACK_PAGES,
+    NETDATA_ZSWAP_SAME_FILLED_PAGES,
+    NETDATA_ZSWAP_DUPLICATE_ENTRY,
+
+    // Terminator
+    NETDATA_ZSWAP_SITE_END
+};
+
+static struct netdata_zswap_metric zswap_independent_metrics[] = {
+    // https://elixir.bootlin.com/linux/latest/source/mm/zswap.c
+    {.filename = "/sys/kernel/debug/zswap/pool_total_size",
+     .chart_id = "pool_compressed_size",
+     .dimension = "compressed_size",
+     .units = "bytes",
+     .title = "Zswap compressed bytes currently stored",
+     .algorithm = RRD_ALGORITHM_ABSOLUTE,
+     .charttype = RRDSET_TYPE_AREA,
+     .enabled = CONFIG_BOOLEAN_YES,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = NETDATA_CHART_PRIO_SYSTEM_ZSWAP_POOL_TOT_SIZE,
+     .divisor = 1,
+     .convertv = NULL,
+     .value = -1},
+    {.filename = "/sys/kernel/debug/zswap/stored_pages",
+     .chart_id = "pool_raw_size",
+     .dimension = "uncompressed_size",
+     .units = "bytes",
+     .title = "Zswap uncompressed bytes currently stored",
+     .algorithm = RRD_ALGORITHM_ABSOLUTE,
+     .charttype = RRDSET_TYPE_AREA,
+     .enabled = CONFIG_BOOLEAN_YES,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = NETDATA_CHART_PRIO_SYSTEM_ZSWAP_STORED_PAGE,
+     .divisor = 1,
+     .convertv = pages_to_bytes,
+     .value = -1},
+    {.filename = "/sys/kernel/debug/zswap/pool_limit_hit",
+     .chart_id = "pool_limit_hit",
+     .dimension = "limit",
+     .units = "events/s",
+     .title = "Zswap pool limit was reached",
+     .algorithm = RRD_ALGORITHM_INCREMENTAL,
+     .charttype = RRDSET_TYPE_LINE,
+     .enabled = CONFIG_BOOLEAN_YES,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = NETDATA_CHART_PRIO_SYSTEM_ZSWAP_POOL_LIM_HIT,
+     .divisor = 1,
+     .convertv = NULL,
+     .value = -1},
+    {.filename = "/sys/kernel/debug/zswap/written_back_pages",
+     .chart_id = "written_back_raw_bytes",
+     .dimension = "written_back",
+     .units = "bytes/s",
+     .title = "Zswap uncomressed bytes written back when pool limit was reached",
+     .algorithm = RRD_ALGORITHM_INCREMENTAL,
+     .charttype = RRDSET_TYPE_AREA,
+     .enabled = CONFIG_BOOLEAN_YES,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = NETDATA_CHART_PRIO_SYSTEM_ZSWAP_WRT_BACK_PAGES,
+     .divisor = 1,
+     .convertv = pages_to_bytes,
+     .value = -1},
+    {.filename = "/sys/kernel/debug/zswap/same_filled_pages",
+     .chart_id = "same_filled_raw_size",
+     .dimension = "same_filled",
+     .units = "bytes",
+     .title = "Zswap same-value filled uncompressed bytes currently stored",
+     .algorithm = RRD_ALGORITHM_ABSOLUTE,
+     .charttype = RRDSET_TYPE_AREA,
+     .enabled = CONFIG_BOOLEAN_YES,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = NETDATA_CHART_PRIO_SYSTEM_ZSWAP_SAME_FILL_PAGE,
+     .divisor = 1,
+     .convertv = pages_to_bytes,
+     .value = -1},
+    {.filename = "/sys/kernel/debug/zswap/duplicate_entry",
+     .chart_id = "duplicate_entry",
+     .dimension = "duplicate",
+     .units = "entries/s",
+     .title = "Zswap duplicate store was encountered",
+     .algorithm = RRD_ALGORITHM_INCREMENTAL,
+     .charttype = RRDSET_TYPE_LINE,
+     .enabled = CONFIG_BOOLEAN_YES,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = NETDATA_CHART_PRIO_SYSTEM_ZSWAP_DUPP_ENTRY,
+     .divisor = 1,
+     .convertv = NULL,
+     .value = -1},
+
+    // The terminator
+    {.filename = NULL,
+     .chart_id = NULL,
+     .dimension = NULL,
+     .units = NULL,
+     .title = NULL,
+     .algorithm = RRD_ALGORITHM_ABSOLUTE,
+     .charttype = RRDSET_TYPE_LINE,
+     .enabled = CONFIG_BOOLEAN_NO,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = -1,
+     .value = -1}};
+
+enum netdata_zswap_rejected {
+    NETDATA_ZSWAP_REJECTED_CHART,
+    NETDATA_ZSWAP_REJECTED_COMPRESS_POOR,
+    NETDATA_ZSWAP_REJECTED_KMEM_FAIL,
+    NETDATA_ZSWAP_REJECTED_RALLOC_FAIL,
+    NETDATA_ZSWAP_REJECTED_RRECLAIM_FAIL,
+
+    // Terminator
+    NETDATA_ZSWAP_REJECTED_END
+};
+
+static struct netdata_zswap_metric zswap_rejected_metrics[] = {
+    {.filename = "/sys/kernel/debug/zswap/",
+     .chart_id = "rejections",
+     .dimension = NULL,
+     .units = "rejections/s",
+     .title = "Zswap rejections",
+     .algorithm = RRD_ALGORITHM_INCREMENTAL,
+     .charttype = RRDSET_TYPE_STACKED,
+     .enabled = CONFIG_BOOLEAN_YES,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = NETDATA_CHART_PRIO_SYSTEM_ZSWAP_REJECTS,
+     .divisor = 1,
+     .convertv = NULL,
+     .value = -1},
+    {.filename = "/sys/kernel/debug/zswap/reject_compress_poor",
+     .chart_id = "reject_compress_poor",
+     .dimension = "compress_poor",
+     .units = NULL,
+     .title = NULL,
+     .algorithm = RRD_ALGORITHM_INCREMENTAL,
+     .charttype = RRDSET_TYPE_STACKED,
+     .enabled = CONFIG_BOOLEAN_YES,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = NETDATA_CHART_PRIO_SYSTEM_ZSWAP_REJECTS,
+     .divisor = 1,
+     .convertv = NULL,
+     .value = -1},
+    {.filename = "/sys/kernel/debug/zswap/reject_kmemcache_fail",
+     .chart_id = "reject_kmemcache_fail",
+     .dimension = "kmemcache_fail",
+     .units = NULL,
+     .title = NULL,
+     .algorithm = RRD_ALGORITHM_INCREMENTAL,
+     .charttype = RRDSET_TYPE_STACKED,
+     .enabled = CONFIG_BOOLEAN_YES,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = NETDATA_CHART_PRIO_SYSTEM_ZSWAP_REJECTS,
+     .divisor = 1,
+     .convertv = NULL,
+     .value = -1},
+    {.filename = "/sys/kernel/debug/zswap/reject_alloc_fail",
+     .chart_id = "reject_alloc_fail",
+     .dimension = "alloc_fail",
+     .units = NULL,
+     .title = NULL,
+     .algorithm = RRD_ALGORITHM_INCREMENTAL,
+     .charttype = RRDSET_TYPE_STACKED,
+     .enabled = CONFIG_BOOLEAN_YES,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = NETDATA_CHART_PRIO_SYSTEM_ZSWAP_REJECTS,
+     .divisor = 1,
+     .convertv = NULL,
+     .value = -1},
+    {.filename = "/sys/kernel/debug/zswap/reject_reclaim_fail",
+     .chart_id = "reject_reclaim_fail",
+     .dimension = "reclaim_fail",
+     .units = NULL,
+     .title = NULL,
+     .algorithm = RRD_ALGORITHM_INCREMENTAL,
+     .charttype = RRDSET_TYPE_STACKED,
+     .enabled = CONFIG_BOOLEAN_YES,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = NETDATA_CHART_PRIO_SYSTEM_ZSWAP_REJECTS,
+     .divisor = 1,
+     .convertv = NULL,
+     .value = -1},
+
+    // The terminator
+    {.filename = NULL,
+     .chart_id = NULL,
+     .dimension = NULL,
+     .units = NULL,
+     .title = NULL,
+     .algorithm = RRD_ALGORITHM_ABSOLUTE,
+     .charttype = RRDSET_TYPE_STACKED,
+     .enabled = CONFIG_BOOLEAN_NO,
+     .chart_created = CONFIG_BOOLEAN_NO,
+     .prio = -1,
+     .value = -1}};
+
+int zswap_collect_data(struct netdata_zswap_metric *metric)
+{
+    int fd;
+    int ret = 0;
+    char buffer[512];
+
+    char filename[FILENAME_MAX + 1];
+    snprintfz(filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, metric->filename);
+    // we are not using profile_open/procfile_read, because they will generate error during runtime.
+    fd = open(filename, O_RDONLY, 0444);
+    if (fd < 0) {
+        error("Cannot open file %s", filename);
+        return -1;
+    }
+
+    ssize_t r = read(fd, buffer, 511);
+    // We expect at list 1 character
+    if (r < 2) {
+        error("Cannot parse file %s", filename);
+        ret = -1;
+        goto zswap_collect_end;
+    }
+
+    // We discard breakline
+    buffer[r - 1] = '\0';
+    metric->value = str2ll(buffer, NULL);
+
+    if (metric->convertv)
+        metric->value = metric->convertv(metric->value);
+
+zswap_collect_end:
+    close(fd);
+    return ret;
+}
+
+static void
+zswap_send_chart(struct netdata_zswap_metric *metric, int update_every, const char *name, const char *option)
+{
+    fprintf(
+        stdout,
+        "CHART system.zswap_%s '' '%s' '%s' 'zswap' '' '%s' %d %d '%s' 'debugfs.plugin' '%s'\n",
+        metric->chart_id,
+        metric->title,
+        metric->units,
+        debugfs_rrdset_type_name(metric->charttype),
+        metric->prio,
+        update_every,
+        (!option) ? "" : option,
+        name);
+}
+
+static void zswap_send_dimension(struct netdata_zswap_metric *metric)
+{
+    int div = metric->divisor > 0 ? metric->divisor : 1;
+    fprintf(
+        stdout,
+        "DIMENSION '%s' '%s' %s 1 %d ''\n",
+        metric->dimension,
+        metric->dimension,
+        debugfs_rrd_algorithm_name(metric->algorithm),
+        div);
+}
+
+static void zswap_send_begin(struct netdata_zswap_metric *metric)
+{
+    fprintf(stdout, "BEGIN system.zswap_%s\n", metric->chart_id);
+}
+
+static void zswap_send_set(struct netdata_zswap_metric *metric)
+{
+    fprintf(stdout, "SET %s = %lld\n", metric->dimension, metric->value);
+}
+
+static void zswap_send_end_and_flush()
+{
+    fprintf(stdout, "END\n");
+    fflush(stdout);
+}
+
+static void zswap_independent_chart(struct netdata_zswap_metric *metric, int update_every, const char *name)
+{
+    if (unlikely(!metric->chart_created)) {
+        metric->chart_created = CONFIG_BOOLEAN_YES;
+
+        zswap_send_chart(metric, update_every, name, NULL);
+        zswap_send_dimension(metric);
+    }
+
+    zswap_send_begin(metric);
+    zswap_send_set(metric);
+    zswap_send_end_and_flush();
+}
+
+void zswap_reject_chart(int update_every, const char *name)
+{
+    struct netdata_zswap_metric *metric = &zswap_rejected_metrics[NETDATA_ZSWAP_REJECTED_CHART];
+
+    if (unlikely(!metric->chart_created)) {
+        metric->chart_created = CONFIG_BOOLEAN_YES;
+
+        zswap_send_chart(metric, update_every, name, NULL);
+        for (int i = NETDATA_ZSWAP_REJECTED_COMPRESS_POOR; zswap_rejected_metrics[i].filename; i++) {
+            metric = &zswap_rejected_metrics[i];
+            if (likely(metric->enabled))
+                zswap_send_dimension(metric);
+        }
+    }
+
+    metric = &zswap_rejected_metrics[NETDATA_ZSWAP_REJECTED_CHART];
+    zswap_send_begin(metric);
+    for (int i = NETDATA_ZSWAP_REJECTED_COMPRESS_POOR; zswap_rejected_metrics[i].filename; i++) {
+        metric = &zswap_rejected_metrics[i];
+        if (likely(metric->enabled))
+            zswap_send_set(metric);
+    }
+    zswap_send_end_and_flush();
+}
+
+static void zswap_obsolete_charts(int update_every, const char *name)
+{
+    struct netdata_zswap_metric *metric = NULL;
+
+    for (int i = 0; zswap_independent_metrics[i].filename; i++) {
+        metric = &zswap_independent_metrics[i];
+        if (likely(metric->chart_created))
+            zswap_send_chart(metric, update_every, name, "obsolete");
+    }
+
+    metric = &zswap_rejected_metrics[NETDATA_ZSWAP_REJECTED_CHART];
+    if (likely(metric->chart_created))
+        zswap_send_chart(metric, update_every, name, "obsolete");
+
+    metric = &zswap_calculated_metrics[NETDATA_ZSWAP_COMPRESSION_RATIO_CHART];
+    if (likely(metric->chart_created))
+        zswap_send_chart(metric, update_every, name, "obsolete");
+}
+
+int do_debugfs_zswap(int update_every, const char *name)
+{
+    system_page_size = sysconf(_SC_PAGESIZE);
+    struct netdata_zswap_metric *metric = NULL;
+    int enabled = 0;
+
+    for (int i = 0; zswap_independent_metrics[i].filename; i++) {
+        metric = &zswap_independent_metrics[i];
+        if (unlikely(!metric->enabled))
+            continue;
+        if (unlikely(!(metric->enabled = !zswap_collect_data(metric))))
+            continue;
+        zswap_independent_chart(metric, update_every, name);
+        enabled++;
+    }
+
+    struct netdata_zswap_metric *metric_size = &zswap_independent_metrics[NETDATA_ZSWAP_POOL_TOTAL_SIZE];
+    struct netdata_zswap_metric *metric_raw_size = &zswap_independent_metrics[NETDATA_ZSWAP_STORED_PAGES];
+    if (metric_size->enabled && metric_raw_size->enabled) {
+        metric = &zswap_calculated_metrics[NETDATA_ZSWAP_COMPRESSION_RATIO_CHART];
+        metric->value = 0;
+        if (metric_size->value > 0)
+            metric->value =
+                (collected_number)((NETDATA_DOUBLE)metric_raw_size->value / (NETDATA_DOUBLE)metric_size->value * 100);
+        zswap_independent_chart(metric, update_every, name);
+    }
+
+    int enabled_rejected = 0;
+    for (int i = NETDATA_ZSWAP_REJECTED_COMPRESS_POOR; zswap_rejected_metrics[i].filename; i++) {
+        metric = &zswap_rejected_metrics[i];
+        if (unlikely(!metric->enabled))
+            continue;
+        if (unlikely(!(metric->enabled = !zswap_collect_data(metric))))
+            continue;
+        enabled++;
+        enabled_rejected++;
+    }
+
+    if (likely(enabled_rejected > 0))
+        zswap_reject_chart(update_every, name);
+
+    if (!enabled) {
+        zswap_obsolete_charts(update_every, name);
+        return -1;
+    }
+
+    return 0;
+}
--- a/collectors/debugfs.plugin/metrics.csv
+++ b/collectors/debugfs.plugin/metrics.csv
@ -0,0 +1,12 @@
+metric,scode,dimensions,unit,description,chart_type,labels,plugin,module
+mem.fragmentation_index_dma,node,"order0, order1, order2, order3, order4, order5, order6, order7, order8, order9, order10",index,Memory fragmentation index for each order,line,numa_node,debugfs.plugin,/sys/kernel/debug/extfrag
+mem.fragmentation_index_dma32,node,"order0, order1, order2, order3, order4, order5, order6, order7, order8, order9, order10",index,Memory fragmentation index for each order,line,numa_node,debugfs.plugin,/sys/kernel/debug/extfrag
+mem.fragmentation_index_normal,node,"order0, order1, order2, order3, order4, order5, order6, order7, order8, order9, order10",index,Memory fragmentation index for each order,line,numa_node,debugfs.plugin,/sys/kernel/debug/extfrag
+system.zswap_pool_compression_ratio,,compression_ratio,ratio,Zswap compression ratio,line,,debugfs.plugin,/sys/kernel/debug/zswap
+system.zswap_pool_compressed_size,,compressed_size,bytes,Zswap compressed bytes currently stored,area,,debugfs.plugin,/sys/kernel/debug/zswap
+system.zswap_pool_raw_size,,uncompressed_size,bytes,Zswap uncompressed bytes currently stored,area,,debugfs.plugin,/sys/kernel/debug/zswap
+system.zswap_rejections,,"compress_poor, kmemcache_fail, alloc_fail, reclaim_fail",rejections/s,Zswap rejections,stacked,,debugfs.plugin,/sys/kernel/debug/zswap
+system.zswap_pool_limit_hit,,limit,events/s,Zswap pool limit was reached,line,,debugfs.plugin,/sys/kernel/debug/zswap
+system.zswap_written_back_raw_bytes,,written_back,bytes/s,Zswap uncomressed bytes written back when pool limit was reached,area,,debugfs.plugin,/sys/kernel/debug/zswap
+system.zswap_same_filled_raw_size,,same_filled,bytes,Zswap same-value filled uncompressed bytes currently stored,area,,debugfs.plugin,/sys/kernel/debug/zswap
+system.zswap_duplicate_entry,,duplicate,entries/s,Zswap duplicate store was encountered,line,,debugfs.plugin,/sys/kernel/debug/zswap
--- a/collectors/ebpf.plugin/ebpf_swap.c
+++ b/collectors/ebpf.plugin/ebpf_swap.c
@ -752,7 +752,7 @@ static void ebpf_create_swap_charts(int update_every)
                      EBPF_COMMON_DIMENSION_CALL, NETDATA_SYSTEM_SWAP_SUBMENU,
                      NULL,
                      NETDATA_EBPF_CHART_TYPE_LINE,
-                      202,
+                      NETDATA_CHART_PRIO_SYSTEM_SWAP_CALLS,
                      ebpf_create_global_dimension,
                      swap_publish_aggregated, NETDATA_SWAP_END,
                      update_every, NETDATA_EBPF_MODULE_NAME_SWAP);
--- a/configure.ac
+++ b/configure.ac
@ -1293,6 +1293,21 @@ if test "${build_ml}" = "yes"; then
 fi


+# -----------------------------------------------------------------------------
+# debugfs.plugin
+
+if test "${build_target}" = "linux"; then
+    AC_DEFINE([ENABLE_DEBUGFS_PLUGIN], [1], [debugfs.plugin])
+    enable_plugin_debugfs="yes"
+else
+    enable_plugin_debugfs="no"
+fi
+
+AC_MSG_CHECKING([if debugfs.plugin should be enabled])
+AC_MSG_RESULT([${enable_plugin_debugfs}])
+AM_CONDITIONAL([ENABLE_PLUGIN_DEBUGFS], [test "${enable_plugin_debugfs}" = "yes"])
+
+
 # -----------------------------------------------------------------------------
 # ebpf.plugin

@ -1808,6 +1823,7 @@ AC_CONFIG_FILES([
    collectors/apps.plugin/Makefile
    collectors/cgroups.plugin/Makefile
    collectors/charts.d.plugin/Makefile
+    collectors/debugfs.plugin/Makefile
    collectors/diskspace.plugin/Makefile
    collectors/timex.plugin/Makefile
    collectors/ioping.plugin/Makefile
--- a/contrib/debian/netdata.postinst
+++ b/contrib/debian/netdata.postinst
@ -61,6 +61,7 @@ case "$1" in
    chown -R root:netdata /usr/libexec/netdata/plugins.d
    setcap cap_dac_read_search,cap_sys_ptrace+ep /usr/libexec/netdata/plugins.d/apps.plugin
    setcap cap_dac_read_search+ep /usr/libexec/netdata/plugins.d/slabinfo.plugin
+    setcap cap_dac_read_search+ep /usr/libexec/netdata/plugins.d/debugfs.plugin

    if capsh --supports=cap_perfmon 2>/dev/null; then
        setcap cap_perfmon+ep /usr/libexec/netdata/plugins.d/perf.plugin
--- a/contrib/debian/rules
+++ b/contrib/debian/rules
@ -113,6 +113,7 @@ override_dh_fixperms:
 	# given extra capabilities in the postinst script.
 	#
 	chmod 0750 $(TOP)/usr/libexec/netdata/plugins.d/apps.plugin
+	chmod 0750 $(TOP)/usr/libexec/netdata/plugins.d/debugfs.plugin
 	chmod 0750 $(TOP)/usr/libexec/netdata/plugins.d/perf.plugin
 	chmod 0750 $(TOP)/usr/libexec/netdata/plugins.d/slabinfo.plugin
 	chmod 0750 $(TOP)/usr/libexec/netdata/plugins.d/go.d.plugin
--- a/daemon/buildinfo.c
+++ b/daemon/buildinfo.c
@ -115,6 +115,12 @@
 #define FEAT_APPS_PLUGIN 0
 #endif

+#ifdef ENABLE_DEBUGFS_PLUGIN
+#define FEAT_DEBUGFS_PLUGIN 1
+#else
+#define FEAT_DEBUGFS_PLUGIN 0
+#endif
+
 #ifdef HAVE_FREEIPMI
 #define FEAT_IPMI 1
 #else
@ -291,6 +297,7 @@ void print_build_info(void) {
    printf("    apps:                    %s\n", FEAT_YES_NO(FEAT_APPS_PLUGIN));
    printf("    cgroup Network Tracking: %s\n", FEAT_YES_NO(FEAT_CGROUP_NET));
    printf("    CUPS:                    %s\n", FEAT_YES_NO(FEAT_CUPS));
+    printf("    debugfs:                 %s\n", FEAT_YES_NO(FEAT_DEBUGFS_PLUGIN));
    printf("    EBPF:                    %s\n", FEAT_YES_NO(FEAT_EBPF));
    printf("    IPMI:                    %s\n", FEAT_YES_NO(FEAT_IPMI));
    printf("    NFACCT:                  %s\n", FEAT_YES_NO(FEAT_NFACCT));
@ -349,6 +356,7 @@ void print_build_info_json(void) {
    printf("    \"apps\": %s,\n",             FEAT_JSON_BOOL(FEAT_APPS_PLUGIN));
    printf("    \"cgroup-net\": %s,\n",       FEAT_JSON_BOOL(FEAT_CGROUP_NET));
    printf("    \"cups\": %s,\n",             FEAT_JSON_BOOL(FEAT_CUPS));
+    printf("    \"debugfs\": %s,\n",          FEAT_JSON_BOOL(FEAT_DEBUGFS_PLUGIN));
    printf("    \"ebpf\": %s,\n",             FEAT_JSON_BOOL(FEAT_EBPF));
    printf("    \"ipmi\": %s,\n",             FEAT_JSON_BOOL(FEAT_IPMI));
    printf("    \"nfacct\": %s,\n",           FEAT_JSON_BOOL(FEAT_NFACCT));
@ -424,6 +432,9 @@ void analytics_build_info(BUFFER *b) {
 #ifdef ENABLE_APPS_PLUGIN
    add_to_bi(b, "apps");
 #endif
+#ifdef ENABLE_DEBUGFS_PLUGIN
+    add_to_bi(b, "debugfs");
+#endif
 #ifdef HAVE_SETNS
    add_to_bi(b, "cgroup Network Tracking");
 #endif
--- a/netdata-installer.sh
+++ b/netdata-installer.sh
@ -1229,6 +1229,23 @@ if [ "$(id -u)" -eq 0 ]; then
    fi
  fi

+  if [ -f "${NETDATA_PREFIX}/usr/libexec/netdata/plugins.d/debugfs.plugin" ]; then
+    run chown "root:${NETDATA_GROUP}" "${NETDATA_PREFIX}/usr/libexec/netdata/plugins.d/debugfs.plugin"
+    capabilities=0
+    if ! iscontainer && command -v setcap 1> /dev/null 2>&1; then
+      run chmod 0750 "${NETDATA_PREFIX}/usr/libexec/netdata/plugins.d/debugfs.plugin"
+      if run setcap cap_dac_read_search+ep "${NETDATA_PREFIX}/usr/libexec/netdata/plugins.d/debugfs.plugin"; then
+        # if we managed to setcap, but we fail to execute debugfs.plugin setuid to root
+        "${NETDATA_PREFIX}/usr/libexec/netdata/plugins.d/debugfs.plugin" -t > /dev/null 2>&1 && capabilities=1 || capabilities=0
+      fi
+    fi
+
+    if [ $capabilities -eq 0 ]; then
+      # fix debugfs.plugin to be setuid to root
+      run chmod 4750 "${NETDATA_PREFIX}/usr/libexec/netdata/plugins.d/debugfs.plugin"
+    fi
+  fi
+
  if [ -f "${NETDATA_PREFIX}/usr/libexec/netdata/plugins.d/freeipmi.plugin" ]; then
    run chown "root:${NETDATA_GROUP}" "${NETDATA_PREFIX}/usr/libexec/netdata/plugins.d/freeipmi.plugin"
    run chmod 4750 "${NETDATA_PREFIX}/usr/libexec/netdata/plugins.d/freeipmi.plugin"
--- a/netdata.spec.in
+++ b/netdata.spec.in
@ -280,6 +280,10 @@ install -m 4750 -p freeipmi.plugin "${RPM_BUILD_ROOT}%{_libexecdir}/%{name}/plug
 # Install apps.plugin
 install -m 4750 -p apps.plugin "${RPM_BUILD_ROOT}%{_libexecdir}/%{name}/plugins.d/apps.plugin"

+# ###########################################################
+# Install debugfs.plugin
+install -m 0750 -p debugfs.plugin "${RPM_BUILD_ROOT}%{_libexecdir}/%{name}/plugins.d/debugfs.plugin"
+
 # ###########################################################
 # Install perf.plugin
 install -m 4750 -p perf.plugin "${RPM_BUILD_ROOT}%{_libexecdir}/%{name}/plugins.d/perf.plugin"
@ -501,7 +505,10 @@ rm -rf "${RPM_BUILD_ROOT}"
 # %caps(cap_perfmon=ep) %attr(0750,root,netdata) %{_libexecdir}/%{name}/plugins.d/perf.plugin
 %caps(cap_sys_admin=ep) %attr(0750,root,netdata) %{_libexecdir}/%{name}/plugins.d/perf.plugin

-# perf plugin
+# debugfs plugin
+%caps(cap_dac_read_search=ep) %attr(0750,root,netdata) %{_libexecdir}/%{name}/plugins.d/debugfs.plugin
+
+# slabinfo plugin
 %caps(cap_dac_read_search=ep) %attr(0750,root,netdata) %{_libexecdir}/%{name}/plugins.d/slabinfo.plugin

 # go.d.plugin (the capability required for wireguard module)
--- a/packaging/docker/Dockerfile
+++ b/packaging/docker/Dockerfile
@ -104,7 +104,8 @@ RUN chown -R root:root \
    chmod 0755 /usr/libexec/netdata/plugins.d/*.plugin && \
    chmod 4755 \
        /usr/libexec/netdata/plugins.d/cgroup-network \
-        /usr/libexec/netdata/plugins.d/apps.plugin && \
+        /usr/libexec/netdata/plugins.d/apps.plugin \
+        /usr/libexec/netdata/plugins.d/debugfs.plugin && \
    if [ -f /usr/libexec/netdata/plugins.d/freeipmi.plugin ]; then \
        chmod 4755 /usr/libexec/netdata/plugins.d/freeipmi.plugin; \
    fi && \
--- a/packaging/makeself/install-or-update.sh
+++ b/packaging/makeself/install-or-update.sh
@ -171,6 +171,7 @@ progress "changing plugins ownership and permissions"
 if command -v setcap >/dev/null 2>&1; then
    run setcap "cap_dac_read_search,cap_sys_ptrace=ep" "usr/libexec/netdata/plugins.d/apps.plugin"
    run setcap "cap_dac_read_search=ep" "usr/libexec/netdata/plugins.d/slabinfo.plugin"
+    run setcap "cap_dac_read_search=ep" "usr/libexec/netdata/plugins.d/debugfs.plugin"

    if command -v capsh >/dev/null 2>&1 && capsh --supports=cap_perfmon 2>/dev/null ; then
        run setcap "cap_perfmon=ep" "usr/libexec/netdata/plugins.d/perf.plugin"
@ -180,7 +181,7 @@ if command -v setcap >/dev/null 2>&1; then

    run setcap "cap_net_admin,cap_net_raw=eip" "usr/libexec/netdata/plugins.d/go.d.plugin"
 else
-  for x in apps.plugin perf.plugin slabinfo.plugin; do
+  for x in apps.plugin perf.plugin slabinfo.plugin debugfs.plugin; do
    f="usr/libexec/netdata/plugins.d/${x}"
    run chown root:${NETDATA_GROUP} "${f}"
    run chmod 4750 "${f}"
--- a/web/gui/dashboard_info.js
+++ b/web/gui/dashboard_info.js
@ -883,6 +883,19 @@ netdataDashboard.submenu = {
        'When the kernel or an application requests some memory, the buddy allocator provides a page that matches closest the request.'
    },

+    'mem.fragmentation': {
+        info: 'These charts show whether the kernel will compact memory or direct reclaim to satisfy a high-order allocation. '+
+            'The extfrag/extfrag_index file in debugfs shows what the fragmentation index for each order is in each zone in the system.' +
+            'Values tending towards 0 imply allocations would fail due to lack of memory, values towards 1000 imply failures are due to ' +
+            'fragmentation and -1 implies that the allocation will succeed as long as watermarks are met.'
+    },
+
+    'system.zswap': {
+        info : 'Zswap is a backend for frontswap that takes pages that are in the process of being swapped out and attempts to compress and store them in a ' +
+            'RAM-based memory pool.  This can result in a significant I/O reduction on the swap device and, in the case where decompressing from RAM is faster ' +
+            'than reading from the swap device, can also improve workload performance.'
+    },
+
    'ip.ecn': {
        info: '<a href="https://en.wikipedia.org/wiki/Explicit_Congestion_Notification" target="_blank">Explicit Congestion Notification (ECN)</a> '+
        'is an extension to the IP and to the TCP that allows end-to-end notification of network congestion without dropping packets. '+
@ -1522,6 +1535,14 @@ netdataDashboard.context = {
        info: '<a href="https://en.wikipedia.org/wiki/Entropy_(computing)" target="_blank">Entropy</a>, is a pool of random numbers (<a href="https://en.wikipedia.org/wiki//dev/random" target="_blank">/dev/random</a>) that is mainly used in cryptography. If the pool of entropy gets empty, processes requiring random numbers may run a lot slower (it depends on the interface each program uses), waiting for the pool to be replenished. Ideally a system with high entropy demands should have a hardware device for that purpose (TPM is one such device). There are also several software-only options you may install, like <code>haveged</code>, although these are generally useful only in servers.'
    },

+    'system.zswap_rejections': {
+        info: '<p>Zswap rejected pages per access.</p>' +
+            '<p><b>CompressPoor</b> - compressed page was too big for the allocator to store. ' +
+            '<b>KmemcacheFail</b> - number of entry metadata that could not be allocated. ' +
+            '<b>AllocFail</b> - allocator could not get memory. ' +
+            '<b>ReclaimFail</b> - memory cannot be reclaimed (pool limit was reached).</p>'
+    },
+
    'system.clock_sync_state': {
        info:'<p>The system clock synchronization state as provided by the <a href="https://man7.org/linux/man-pages/man2/adjtimex.2.html" target="_blank">ntp_adjtime()</a> system call. '+
        'An unsynchronized clock may be the result of synchronization issues by the NTP daemon or a hardware clock fault. '+