src/collectors/ebpf.plugin/ebpf_cachestat.c
// SPDX-License-Identifier: GPL-3.0-or-later
#include "ebpf.h"
#include "ebpf_cachestat.h"
static char *cachestat_counter_dimension_name[NETDATA_CACHESTAT_END] = { "ratio", "dirty", "hit",
"miss" };
static netdata_syscall_stat_t cachestat_counter_aggregated_data[NETDATA_CACHESTAT_END];
static netdata_publish_syscall_t cachestat_counter_publish_aggregated[NETDATA_CACHESTAT_END];
netdata_cachestat_pid_t *cachestat_vector = NULL;
static netdata_idx_t cachestat_hash_values[NETDATA_CACHESTAT_END];
static netdata_idx_t *cachestat_values = NULL;
ebpf_local_maps_t cachestat_maps[] = {{.name = "cstat_global", .internal_input = NETDATA_CACHESTAT_END,
.user_input = 0, .type = NETDATA_EBPF_MAP_STATIC,
.map_fd = ND_EBPF_MAP_FD_NOT_INITIALIZED,
#ifdef LIBBPF_MAJOR_VERSION
.map_type = BPF_MAP_TYPE_PERCPU_ARRAY
#endif
},
{.name = "cstat_pid", .internal_input = ND_EBPF_DEFAULT_PID_SIZE,
.user_input = 0,
.type = NETDATA_EBPF_MAP_RESIZABLE | NETDATA_EBPF_MAP_PID,
.map_fd = ND_EBPF_MAP_FD_NOT_INITIALIZED,
#ifdef LIBBPF_MAJOR_VERSION
.map_type = BPF_MAP_TYPE_PERCPU_HASH
#endif
},
{.name = "cstat_ctrl", .internal_input = NETDATA_CONTROLLER_END,
.user_input = 0,
.type = NETDATA_EBPF_MAP_CONTROLLER,
.map_fd = ND_EBPF_MAP_FD_NOT_INITIALIZED,
#ifdef LIBBPF_MAJOR_VERSION
.map_type = BPF_MAP_TYPE_PERCPU_ARRAY
#endif
},
{.name = NULL, .internal_input = 0, .user_input = 0,
.type = NETDATA_EBPF_MAP_CONTROLLER,
.map_fd = ND_EBPF_MAP_FD_NOT_INITIALIZED,
#ifdef LIBBPF_MAJOR_VERSION
#endif
}};
struct config cachestat_config = { .first_section = NULL,
.last_section = NULL,
.mutex = NETDATA_MUTEX_INITIALIZER,
.index = { .avl_tree = { .root = NULL, .compar = appconfig_section_compare },
.rwlock = AVL_LOCK_INITIALIZER } };
netdata_ebpf_targets_t cachestat_targets[] = { {.name = "add_to_page_cache_lru", .mode = EBPF_LOAD_TRAMPOLINE},
{.name = "mark_page_accessed", .mode = EBPF_LOAD_TRAMPOLINE},
{.name = NULL, .mode = EBPF_LOAD_TRAMPOLINE},
{.name = "mark_buffer_dirty", .mode = EBPF_LOAD_TRAMPOLINE},
{.name = NULL, .mode = EBPF_LOAD_TRAMPOLINE}};
static char *account_page[NETDATA_CACHESTAT_ACCOUNT_DIRTY_END] ={ "account_page_dirtied",
"__set_page_dirty", "__folio_mark_dirty" };
struct netdata_static_thread ebpf_read_cachestat = {
.name = "EBPF_READ_CACHESTAT",
.config_section = NULL,
.config_name = NULL,
.env_name = NULL,
.enabled = 1,
.thread = NULL,
.init_routine = NULL,
.start_routine = NULL
};
#ifdef LIBBPF_MAJOR_VERSION
/**
* Disable probe
*
* Disable all probes to use exclusively another method.
*
* @param obj is the main structure for bpf objects
*/
static void ebpf_cachestat_disable_probe(struct cachestat_bpf *obj)
{
bpf_program__set_autoload(obj->progs.netdata_add_to_page_cache_lru_kprobe, false);
bpf_program__set_autoload(obj->progs.netdata_mark_page_accessed_kprobe, false);
bpf_program__set_autoload(obj->progs.netdata_folio_mark_dirty_kprobe, false);
bpf_program__set_autoload(obj->progs.netdata_set_page_dirty_kprobe, false);
bpf_program__set_autoload(obj->progs.netdata_account_page_dirtied_kprobe, false);
bpf_program__set_autoload(obj->progs.netdata_mark_buffer_dirty_kprobe, false);
}
/*
* Disable specific probe
*
* Disable probes according the kernel version
*
* @param obj is the main structure for bpf objects
*/
static void ebpf_cachestat_disable_specific_probe(struct cachestat_bpf *obj)
{
if (!strcmp(cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name,
account_page[NETDATA_CACHESTAT_FOLIO_DIRTY])) {
bpf_program__set_autoload(obj->progs.netdata_account_page_dirtied_kprobe, false);
bpf_program__set_autoload(obj->progs.netdata_set_page_dirty_kprobe, false);
} else if (!strcmp(cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name,
account_page[NETDATA_CACHESTAT_SET_PAGE_DIRTY])) {
bpf_program__set_autoload(obj->progs.netdata_folio_mark_dirty_kprobe, false);
bpf_program__set_autoload(obj->progs.netdata_account_page_dirtied_kprobe, false);
} else {
bpf_program__set_autoload(obj->progs.netdata_folio_mark_dirty_kprobe, false);
bpf_program__set_autoload(obj->progs.netdata_set_page_dirty_kprobe, false);
}
}
/*
* Disable trampoline
*
* Disable all trampoline to use exclusively another method.
*
* @param obj is the main structure for bpf objects.
*/
static void ebpf_cachestat_disable_trampoline(struct cachestat_bpf *obj)
{
bpf_program__set_autoload(obj->progs.netdata_add_to_page_cache_lru_fentry, false);
bpf_program__set_autoload(obj->progs.netdata_mark_page_accessed_fentry, false);
bpf_program__set_autoload(obj->progs.netdata_folio_mark_dirty_fentry, false);
bpf_program__set_autoload(obj->progs.netdata_set_page_dirty_fentry, false);
bpf_program__set_autoload(obj->progs.netdata_account_page_dirtied_fentry, false);
bpf_program__set_autoload(obj->progs.netdata_mark_buffer_dirty_fentry, false);
}
/*
* Disable specific trampoline
*
* Disable trampoline according to kernel version.
*
* @param obj is the main structure for bpf objects.
*/
static void ebpf_cachestat_disable_specific_trampoline(struct cachestat_bpf *obj)
{
if (!strcmp(cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name,
account_page[NETDATA_CACHESTAT_FOLIO_DIRTY])) {
bpf_program__set_autoload(obj->progs.netdata_account_page_dirtied_fentry, false);
bpf_program__set_autoload(obj->progs.netdata_set_page_dirty_fentry, false);
} else if (!strcmp(cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name,
account_page[NETDATA_CACHESTAT_SET_PAGE_DIRTY])) {
bpf_program__set_autoload(obj->progs.netdata_folio_mark_dirty_fentry, false);
bpf_program__set_autoload(obj->progs.netdata_account_page_dirtied_fentry, false);
} else {
bpf_program__set_autoload(obj->progs.netdata_folio_mark_dirty_fentry, false);
bpf_program__set_autoload(obj->progs.netdata_set_page_dirty_fentry, false);
}
}
/**
* Set trampoline target
*
* Set the targets we will monitor.
*
* @param obj is the main structure for bpf objects.
*/
static inline void netdata_set_trampoline_target(struct cachestat_bpf *obj)
{
bpf_program__set_attach_target(obj->progs.netdata_add_to_page_cache_lru_fentry, 0,
cachestat_targets[NETDATA_KEY_CALLS_ADD_TO_PAGE_CACHE_LRU].name);
bpf_program__set_attach_target(obj->progs.netdata_mark_page_accessed_fentry, 0,
cachestat_targets[NETDATA_KEY_CALLS_MARK_PAGE_ACCESSED].name);
if (!strcmp(cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name,
account_page[NETDATA_CACHESTAT_FOLIO_DIRTY])) {
bpf_program__set_attach_target(obj->progs.netdata_folio_mark_dirty_fentry, 0,
cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name);
} else if (!strcmp(cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name,
account_page[NETDATA_CACHESTAT_SET_PAGE_DIRTY])) {
bpf_program__set_attach_target(obj->progs.netdata_set_page_dirty_fentry, 0,
cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name);
} else {
bpf_program__set_attach_target(obj->progs.netdata_account_page_dirtied_fentry, 0,
cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name);
}
bpf_program__set_attach_target(obj->progs.netdata_mark_buffer_dirty_fentry, 0,
cachestat_targets[NETDATA_KEY_CALLS_MARK_BUFFER_DIRTY].name);
}
/**
* Mount Attach Probe
*
* Attach probes to target
*
* @param obj is the main structure for bpf objects.
*
* @return It returns 0 on success and -1 otherwise.
*/
static int ebpf_cachestat_attach_probe(struct cachestat_bpf *obj)
{
obj->links.netdata_add_to_page_cache_lru_kprobe = bpf_program__attach_kprobe(obj->progs.netdata_add_to_page_cache_lru_kprobe,
false,
cachestat_targets[NETDATA_KEY_CALLS_ADD_TO_PAGE_CACHE_LRU].name);
long ret = libbpf_get_error(obj->links.netdata_add_to_page_cache_lru_kprobe);
if (ret)
return -1;
obj->links.netdata_mark_page_accessed_kprobe = bpf_program__attach_kprobe(obj->progs.netdata_mark_page_accessed_kprobe,
false,
cachestat_targets[NETDATA_KEY_CALLS_MARK_PAGE_ACCESSED].name);
ret = libbpf_get_error(obj->links.netdata_mark_page_accessed_kprobe);
if (ret)
return -1;
if (!strcmp(cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name,
account_page[NETDATA_CACHESTAT_FOLIO_DIRTY])) {
obj->links.netdata_folio_mark_dirty_kprobe = bpf_program__attach_kprobe(obj->progs.netdata_folio_mark_dirty_kprobe,
false,
cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name);
ret = libbpf_get_error(obj->links.netdata_folio_mark_dirty_kprobe);
} else if (!strcmp(cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name,
account_page[NETDATA_CACHESTAT_SET_PAGE_DIRTY])) {
obj->links.netdata_set_page_dirty_kprobe = bpf_program__attach_kprobe(obj->progs.netdata_set_page_dirty_kprobe,
false,
cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name);
ret = libbpf_get_error(obj->links.netdata_set_page_dirty_kprobe);
} else {
obj->links.netdata_account_page_dirtied_kprobe = bpf_program__attach_kprobe(obj->progs.netdata_account_page_dirtied_kprobe,
false,
cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name);
ret = libbpf_get_error(obj->links.netdata_account_page_dirtied_kprobe);
}
if (ret)
return -1;
obj->links.netdata_mark_buffer_dirty_kprobe = bpf_program__attach_kprobe(obj->progs.netdata_mark_buffer_dirty_kprobe,
false,
cachestat_targets[NETDATA_KEY_CALLS_MARK_BUFFER_DIRTY].name);
ret = libbpf_get_error(obj->links.netdata_mark_buffer_dirty_kprobe);
if (ret)
return -1;
return 0;
}
/**
* Adjust Map Size
*
* Resize maps according input from users.
*
* @param obj is the main structure for bpf objects.
* @param em structure with configuration
*/
static void ebpf_cachestat_adjust_map(struct cachestat_bpf *obj, ebpf_module_t *em)
{
ebpf_update_map_size(obj->maps.cstat_pid, &cachestat_maps[NETDATA_CACHESTAT_PID_STATS],
em, bpf_map__name(obj->maps.cstat_pid));
ebpf_update_map_type(obj->maps.cstat_global, &cachestat_maps[NETDATA_CACHESTAT_GLOBAL_STATS]);
ebpf_update_map_type(obj->maps.cstat_pid, &cachestat_maps[NETDATA_CACHESTAT_PID_STATS]);
ebpf_update_map_type(obj->maps.cstat_ctrl, &cachestat_maps[NETDATA_CACHESTAT_CTRL]);
}
/**
* Set hash tables
*
* Set the values for maps according the value given by kernel.
*
* @param obj is the main structure for bpf objects.
*/
static void ebpf_cachestat_set_hash_tables(struct cachestat_bpf *obj)
{
cachestat_maps[NETDATA_CACHESTAT_GLOBAL_STATS].map_fd = bpf_map__fd(obj->maps.cstat_global);
cachestat_maps[NETDATA_CACHESTAT_PID_STATS].map_fd = bpf_map__fd(obj->maps.cstat_pid);
cachestat_maps[NETDATA_CACHESTAT_CTRL].map_fd = bpf_map__fd(obj->maps.cstat_ctrl);
}
/**
* Load and attach
*
* Load and attach the eBPF code in kernel.
*
* @param obj is the main structure for bpf objects.
* @param em structure with configuration
*
* @return it returns 0 on success and -1 otherwise
*/
static inline int ebpf_cachestat_load_and_attach(struct cachestat_bpf *obj, ebpf_module_t *em)
{
netdata_ebpf_targets_t *mt = em->targets;
netdata_ebpf_program_loaded_t test = mt[NETDATA_KEY_CALLS_ADD_TO_PAGE_CACHE_LRU].mode;
if (test == EBPF_LOAD_TRAMPOLINE) {
ebpf_cachestat_disable_probe(obj);
ebpf_cachestat_disable_specific_trampoline(obj);
netdata_set_trampoline_target(obj);
} else {
ebpf_cachestat_disable_trampoline(obj);
ebpf_cachestat_disable_specific_probe(obj);
}
ebpf_cachestat_adjust_map(obj, em);
int ret = cachestat_bpf__load(obj);
if (ret) {
return ret;
}
ret = (test == EBPF_LOAD_TRAMPOLINE) ? cachestat_bpf__attach(obj) : ebpf_cachestat_attach_probe(obj);
if (!ret) {
ebpf_cachestat_set_hash_tables(obj);
ebpf_update_controller(cachestat_maps[NETDATA_CACHESTAT_CTRL].map_fd, em);
}
return ret;
}
#endif
/*****************************************************************
*
* FUNCTIONS TO CLOSE THE THREAD
*
*****************************************************************/
static void ebpf_obsolete_specific_cachestat_charts(char *type, int update_every);
/**
* Obsolete services
*
* Obsolete all service charts created
*
* @param em a pointer to `struct ebpf_module`
*/
static void ebpf_obsolete_cachestat_services(ebpf_module_t *em, char *id)
{
ebpf_write_chart_obsolete(NETDATA_SERVICE_FAMILY,
id,
NETDATA_CACHESTAT_HIT_RATIO_CHART,
"Hit ratio",
EBPF_COMMON_DIMENSION_PERCENTAGE,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE,
NETDATA_SYSTEMD_CACHESTAT_HIT_RATIO_CONTEXT,
21100,
em->update_every);
ebpf_write_chart_obsolete(NETDATA_SERVICE_FAMILY,
id,
NETDATA_CACHESTAT_DIRTY_CHART,
"Number of dirty pages",
EBPF_CACHESTAT_DIMENSION_PAGE,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE,
NETDATA_SYSTEMD_CACHESTAT_MODIFIED_CACHE_CONTEXT,
21101,
em->update_every);
ebpf_write_chart_obsolete(NETDATA_SERVICE_FAMILY,
id,
NETDATA_CACHESTAT_HIT_CHART,
"Number of accessed files",
EBPF_CACHESTAT_DIMENSION_HITS,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE,
NETDATA_SYSTEMD_CACHESTAT_HIT_FILE_CONTEXT,
21102,
em->update_every);
ebpf_write_chart_obsolete(NETDATA_SERVICE_FAMILY,
id,
NETDATA_CACHESTAT_MISSES_CHART,
"Files out of page cache",
EBPF_CACHESTAT_DIMENSION_MISSES,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE,
NETDATA_SYSTEMD_CACHESTAT_MISS_FILES_CONTEXT,
21103,
em->update_every);
}
/**
* Obsolete cgroup chart
*
* Send obsolete for all charts created before to close.
*
* @param em a pointer to `struct ebpf_module`
*/
static inline void ebpf_obsolete_cachestat_cgroup_charts(ebpf_module_t *em) {
pthread_mutex_lock(&mutex_cgroup_shm);
ebpf_cgroup_target_t *ect;
for (ect = ebpf_cgroup_pids; ect ; ect = ect->next) {
if (ect->systemd) {
ebpf_obsolete_cachestat_services(em, ect->name);
continue;
}
ebpf_obsolete_specific_cachestat_charts(ect->name, em->update_every);
}
pthread_mutex_unlock(&mutex_cgroup_shm);
}
/**
* Obsolete global
*
* Obsolete global charts created by thread.
*
* @param em a pointer to `struct ebpf_module`
*/
static void ebpf_obsolete_cachestat_global(ebpf_module_t *em)
{
ebpf_write_chart_obsolete(NETDATA_EBPF_MEMORY_GROUP,
NETDATA_CACHESTAT_HIT_RATIO_CHART,
"",
"Hit ratio",
EBPF_COMMON_DIMENSION_PERCENTAGE,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE,
NULL,
21100,
em->update_every);
ebpf_write_chart_obsolete(NETDATA_EBPF_MEMORY_GROUP,
NETDATA_CACHESTAT_DIRTY_CHART,
"",
"Number of dirty pages",
EBPF_CACHESTAT_DIMENSION_PAGE,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE,
NULL,
21101,
em->update_every);
ebpf_write_chart_obsolete(NETDATA_EBPF_MEMORY_GROUP,
NETDATA_CACHESTAT_HIT_CHART,
"",
"Number of accessed files",
EBPF_CACHESTAT_DIMENSION_HITS,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE,
NULL,
21102,
em->update_every);
ebpf_write_chart_obsolete(NETDATA_EBPF_MEMORY_GROUP,
NETDATA_CACHESTAT_MISSES_CHART,
"",
"Files out of page cache",
EBPF_CACHESTAT_DIMENSION_MISSES,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE,
NULL,
21103,
em->update_every);
}
/**
* Obsolette apps charts
*
* Obsolete apps charts.
*
* @param em a pointer to the structure with the default values.
*/
void ebpf_obsolete_cachestat_apps_charts(struct ebpf_module *em)
{
struct ebpf_target *w;
int update_every = em->update_every;
pthread_mutex_lock(&collect_data_mutex);
for (w = apps_groups_root_target; w; w = w->next) {
if (unlikely(!(w->charts_created & (1<<EBPF_MODULE_CACHESTAT_IDX))))
continue;
ebpf_write_chart_obsolete(NETDATA_APP_FAMILY,
w->clean_name,
"_ebpf_cachestat_hit_ratio",
"Hit ratio",
EBPF_COMMON_DIMENSION_PERCENTAGE,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE,
"app.ebpf_cachestat_hit_ratio",
20260,
update_every);
ebpf_write_chart_obsolete(NETDATA_APP_FAMILY,
w->clean_name,
"_ebpf_cachestat_dirty_pages",
"Number of dirty pages",
EBPF_CACHESTAT_DIMENSION_PAGE,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_STACKED,
"app.ebpf_cachestat_dirty_pages",
20261,
update_every);
ebpf_write_chart_obsolete(NETDATA_APP_FAMILY,
w->clean_name,
"_ebpf_cachestat_access",
"Number of accessed files",
EBPF_CACHESTAT_DIMENSION_HITS,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_STACKED,
"app.ebpf_cachestat_access",
20262,
update_every);
ebpf_write_chart_obsolete(NETDATA_APP_FAMILY,
w->clean_name,
"_ebpf_cachestat_misses",
"Files out of page cache",
EBPF_CACHESTAT_DIMENSION_MISSES,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_STACKED,
"app.ebpf_cachestat_misses",
20263,
update_every);
w->charts_created &= ~(1<<EBPF_MODULE_CACHESTAT_IDX);
}
pthread_mutex_unlock(&collect_data_mutex);
}
/**
* Cachestat exit.
*
* Cancel child and exit.
*
* @param ptr thread data.
*/
static void ebpf_cachestat_exit(void *pptr)
{
ebpf_module_t *em = CLEANUP_FUNCTION_GET_PTR(pptr);
if(!em) return;
if (ebpf_read_cachestat.thread)
nd_thread_signal_cancel(ebpf_read_cachestat.thread);
if (em->enabled == NETDATA_THREAD_EBPF_FUNCTION_RUNNING) {
pthread_mutex_lock(&lock);
if (em->cgroup_charts) {
ebpf_obsolete_cachestat_cgroup_charts(em);
fflush(stdout);
}
if (em->apps_charts & NETDATA_EBPF_APPS_FLAG_CHART_CREATED) {
ebpf_obsolete_cachestat_apps_charts(em);
}
ebpf_obsolete_cachestat_global(em);
fflush(stdout);
pthread_mutex_unlock(&lock);
}
ebpf_update_kernel_memory_with_vector(&plugin_statistics, em->maps, EBPF_ACTION_STAT_REMOVE);
#ifdef LIBBPF_MAJOR_VERSION
if (cachestat_bpf_obj) {
cachestat_bpf__destroy(cachestat_bpf_obj);
cachestat_bpf_obj = NULL;
}
#endif
if (em->objects) {
ebpf_unload_legacy_code(em->objects, em->probe_links);
em->objects = NULL;
em->probe_links = NULL;
}
pthread_mutex_lock(&ebpf_exit_cleanup);
em->enabled = NETDATA_THREAD_EBPF_STOPPED;
ebpf_update_stats(&plugin_statistics, em);
pthread_mutex_unlock(&ebpf_exit_cleanup);
}
/*****************************************************************
*
* COMMON FUNCTIONS
*
*****************************************************************/
/**
* Update publish
*
* Update publish values before to write dimension.
*
* @param out structure that will receive data.
* @param mpa calls for mark_page_accessed during the last second.
* @param mbd calls for mark_buffer_dirty during the last second.
* @param apcl calls for add_to_page_cache_lru during the last second.
* @param apd calls for account_page_dirtied during the last second.
*/
void cachestat_update_publish(netdata_publish_cachestat_t *out, uint64_t mpa, uint64_t mbd,
uint64_t apcl, uint64_t apd)
{
// Adapted algorithm from https://github.com/iovisor/bcc/blob/master/tools/cachestat.py#L126-L138
NETDATA_DOUBLE total = (NETDATA_DOUBLE) (((long long)mpa) - ((long long)mbd));
if (total < 0)
total = 0;
NETDATA_DOUBLE misses = (NETDATA_DOUBLE) ( ((long long) apcl) - ((long long) apd) );
if (misses < 0)
misses = 0;
// If hits are < 0, then its possible misses are overestimate due to possibly page cache read ahead adding
// more pages than needed. In this case just assume misses as total and reset hits.
NETDATA_DOUBLE hits = total - misses;
if (hits < 0 ) {
misses = total;
hits = 0;
}
NETDATA_DOUBLE ratio = (total > 0) ? hits/total : 1;
out->ratio = (long long )(ratio*100);
out->hit = (long long)hits;
out->miss = (long long)misses;
}
/**
* Save previous values
*
* Save values used this time.
*
* @param publish
*/
static void save_previous_values(netdata_publish_cachestat_t *publish) {
publish->prev.mark_page_accessed = cachestat_hash_values[NETDATA_KEY_CALLS_MARK_PAGE_ACCESSED];
publish->prev.account_page_dirtied = cachestat_hash_values[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED];
publish->prev.add_to_page_cache_lru = cachestat_hash_values[NETDATA_KEY_CALLS_ADD_TO_PAGE_CACHE_LRU];
publish->prev.mark_buffer_dirty = cachestat_hash_values[NETDATA_KEY_CALLS_MARK_BUFFER_DIRTY];
}
/**
* Calculate statistics
*
* @param publish the structure where we will store the data.
*/
static void calculate_stats(netdata_publish_cachestat_t *publish) {
if (!publish->prev.mark_page_accessed) {
save_previous_values(publish);
return;
}
uint64_t mpa = cachestat_hash_values[NETDATA_KEY_CALLS_MARK_PAGE_ACCESSED] - publish->prev.mark_page_accessed;
uint64_t mbd = cachestat_hash_values[NETDATA_KEY_CALLS_MARK_BUFFER_DIRTY] - publish->prev.mark_buffer_dirty;
uint64_t apcl = cachestat_hash_values[NETDATA_KEY_CALLS_ADD_TO_PAGE_CACHE_LRU] - publish->prev.add_to_page_cache_lru;
uint64_t apd = cachestat_hash_values[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED] - publish->prev.account_page_dirtied;
save_previous_values(publish);
// We are changing the original algorithm to have a smooth ratio.
cachestat_update_publish(publish, mpa, mbd, apcl, apd);
}
/*****************************************************************
*
* APPS
*
*****************************************************************/
/**
* Apps Accumulator
*
* Sum all values read from kernel and store in the first address.
*
* @param out the vector with read values.
* @param maps_per_core do I need to read all cores?
*/
static void cachestat_apps_accumulator(netdata_cachestat_pid_t *out, int maps_per_core)
{
int i, end = (maps_per_core) ? ebpf_nprocs : 1;
netdata_cachestat_pid_t *total = &out[0];
uint64_t ct = total->ct;
for (i = 1; i < end; i++) {
netdata_cachestat_pid_t *w = &out[i];
total->account_page_dirtied += w->account_page_dirtied;
total->add_to_page_cache_lru += w->add_to_page_cache_lru;
total->mark_buffer_dirty += w->mark_buffer_dirty;
total->mark_page_accessed += w->mark_page_accessed;
if (w->ct > ct)
ct = w->ct;
}
total->ct = ct;
}
/**
* Save Pid values
*
* Save the current values inside the structure
*
* @param out vector used to plot charts
* @param in vector with values read from hash tables.
*/
static inline void cachestat_save_pid_values(netdata_publish_cachestat_t *out, netdata_cachestat_pid_t *in)
{
out->ct = in->ct;
if (!out->current.mark_page_accessed) {
memcpy(&out->current, &in[0], sizeof(netdata_cachestat_pid_t));
return;
}
memcpy(&out->prev, &out->current, sizeof(netdata_cachestat_pid_t));
memcpy(&out->current, &in[0], sizeof(netdata_cachestat_pid_t));
}
/**
* Read APPS table
*
* Read the apps table and store data inside the structure.
*
* @param maps_per_core do I need to read all cores?
*/
static void ebpf_read_cachestat_apps_table(int maps_per_core, int max_period)
{
netdata_cachestat_pid_t *cv = cachestat_vector;
int fd = cachestat_maps[NETDATA_CACHESTAT_PID_STATS].map_fd;
size_t length = sizeof(netdata_cachestat_pid_t);
if (maps_per_core)
length *= ebpf_nprocs;
uint32_t key = 0, next_key = 0;
while (bpf_map_get_next_key(fd, &key, &next_key) == 0) {
if (bpf_map_lookup_elem(fd, &key, cv)) {
goto end_cachestat_loop;
}
cachestat_apps_accumulator(cv, maps_per_core);
ebpf_pid_stat_t *local_pid = ebpf_get_pid_entry(key, cv->tgid);
if (!local_pid)
goto end_cachestat_loop;
netdata_publish_cachestat_t *publish = &local_pid->cachestat;
if (!publish->ct || publish->ct != cv->ct){
cachestat_save_pid_values(publish, cv);
local_pid->not_updated = 0;
} else if (++local_pid->not_updated >= max_period) {
bpf_map_delete_elem(fd, &key);
local_pid->not_updated = 0;
}
end_cachestat_loop:
// We are cleaning to avoid passing data read from one process to other.
memset(cv, 0, length);
key = next_key;
}
}
/**
* Update cgroup
*
* Update cgroup data based in
*
* @param maps_per_core do I need to read all cores?
*/
static void ebpf_update_cachestat_cgroup()
{
ebpf_cgroup_target_t *ect;
pthread_mutex_lock(&mutex_cgroup_shm);
for (ect = ebpf_cgroup_pids; ect; ect = ect->next) {
struct pid_on_target2 *pids;
for (pids = ect->pids; pids; pids = pids->next) {
int pid = pids->pid;
netdata_cachestat_pid_t *out = &pids->cachestat;
ebpf_pid_stat_t *local_pid = ebpf_get_pid_entry(pid, 0);
if (local_pid) {
netdata_publish_cachestat_t *in = &local_pid->cachestat;
memcpy(out, &in->current, sizeof(netdata_cachestat_pid_t));
}
}
}
pthread_mutex_unlock(&mutex_cgroup_shm);
}
/**
* Cachestat sum PIDs
*
* Sum values for all PIDs associated to a group
*
* @param publish output structure.
* @param root structure with listed IPs
*/
void ebpf_cachestat_sum_pids(netdata_publish_cachestat_t *publish, struct ebpf_pid_on_target *root)
{
memcpy(&publish->prev, &publish->current,sizeof(publish->current));
memset(&publish->current, 0, sizeof(publish->current));
netdata_cachestat_pid_t *dst = &publish->current;
while (root) {
int32_t pid = root->pid;
ebpf_pid_stat_t *local_pid = ebpf_get_pid_entry(pid, 0);
if (local_pid) {
netdata_publish_cachestat_t *w = &local_pid->cachestat;
netdata_cachestat_pid_t *src = &w->current;
dst->account_page_dirtied += src->account_page_dirtied;
dst->add_to_page_cache_lru += src->add_to_page_cache_lru;
dst->mark_buffer_dirty += src->mark_buffer_dirty;
dst->mark_page_accessed += src->mark_page_accessed;
}
root = root->next;
}
}
/**
* Resume apps data
*/
void ebpf_resume_apps_data()
{
struct ebpf_target *w;
for (w = apps_groups_root_target; w; w = w->next) {
if (unlikely(!(w->charts_created & (1 << EBPF_MODULE_CACHESTAT_IDX))))
continue;
ebpf_cachestat_sum_pids(&w->cachestat, w->root_pid);
}
}
/**
* Cachestat thread
*
* Thread used to generate cachestat charts.
*
* @param ptr a pointer to `struct ebpf_module`
*
* @return It always return NULL
*/
void *ebpf_read_cachestat_thread(void *ptr)
{
heartbeat_t hb;
heartbeat_init(&hb);
ebpf_module_t *em = (ebpf_module_t *)ptr;
int maps_per_core = em->maps_per_core;
int update_every = em->update_every;
int max_period = update_every * EBPF_CLEANUP_FACTOR;
int counter = update_every - 1;
uint32_t lifetime = em->lifetime;
uint32_t running_time = 0;
usec_t period = update_every * USEC_PER_SEC;
while (!ebpf_plugin_stop() && running_time < lifetime) {
(void)heartbeat_next(&hb, period);
if (ebpf_plugin_stop() || ++counter != update_every)
continue;
pthread_mutex_lock(&collect_data_mutex);
ebpf_read_cachestat_apps_table(maps_per_core, max_period);
ebpf_resume_apps_data();
pthread_mutex_unlock(&collect_data_mutex);
counter = 0;
pthread_mutex_lock(&ebpf_exit_cleanup);
if (running_time && !em->running_time)
running_time = update_every;
else
running_time += update_every;
em->running_time = running_time;
pthread_mutex_unlock(&ebpf_exit_cleanup);
}
return NULL;
}
/**
* Create apps charts
*
* Call ebpf_create_chart to create the charts on apps submenu.
*
* @param em a pointer to the structure with the default values.
*/
void ebpf_cachestat_create_apps_charts(struct ebpf_module *em, void *ptr)
{
struct ebpf_target *root = ptr;
struct ebpf_target *w;
int update_every = em->update_every;
for (w = root; w; w = w->next) {
if (unlikely(!w->exposed))
continue;
ebpf_write_chart_cmd(NETDATA_APP_FAMILY,
w->clean_name,
"_ebpf_cachestat_hit_ratio",
"Hit ratio",
EBPF_COMMON_DIMENSION_PERCENTAGE,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE,
"app.ebpf_cachestat_hit_ratio",
20260,
update_every,
NETDATA_EBPF_MODULE_NAME_CACHESTAT);
ebpf_create_chart_labels("app_group", w->name, RRDLABEL_SRC_AUTO);
ebpf_commit_label();
fprintf(stdout, "DIMENSION ratio '' %s 1 1\n", ebpf_algorithms[NETDATA_EBPF_ABSOLUTE_IDX]);
ebpf_write_chart_cmd(NETDATA_APP_FAMILY,
w->clean_name,
"_ebpf_cachestat_dirty_pages",
"Number of dirty pages",
EBPF_CACHESTAT_DIMENSION_PAGE,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE,
"app.ebpf_cachestat_dirty_pages",
20261,
update_every,
NETDATA_EBPF_MODULE_NAME_CACHESTAT);
ebpf_create_chart_labels("app_group", w->name, RRDLABEL_SRC_AUTO);
ebpf_commit_label();
fprintf(stdout, "DIMENSION pages '' %s 1 1\n", ebpf_algorithms[NETDATA_EBPF_INCREMENTAL_IDX]);
ebpf_write_chart_cmd(NETDATA_APP_FAMILY,
w->clean_name,
"_ebpf_cachestat_access",
"Number of accessed files",
EBPF_CACHESTAT_DIMENSION_HITS,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_STACKED,
"app.ebpf_cachestat_access",
20262,
update_every,
NETDATA_EBPF_MODULE_NAME_CACHESTAT);
ebpf_create_chart_labels("app_group", w->name, RRDLABEL_SRC_AUTO);
ebpf_commit_label();
fprintf(stdout, "DIMENSION hits '' %s 1 1\n", ebpf_algorithms[NETDATA_EBPF_ABSOLUTE_IDX]);
ebpf_write_chart_cmd(NETDATA_APP_FAMILY,
w->clean_name,
"_ebpf_cachestat_misses",
"Files out of page cache",
EBPF_CACHESTAT_DIMENSION_MISSES,
NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_STACKED,
"app.ebpf_cachestat_misses",
20263,
update_every,
NETDATA_EBPF_MODULE_NAME_CACHESTAT);
ebpf_create_chart_labels("app_group", w->name, RRDLABEL_SRC_AUTO);
ebpf_commit_label();
fprintf(stdout, "DIMENSION misses '' %s 1 1\n", ebpf_algorithms[NETDATA_EBPF_ABSOLUTE_IDX]);
w->charts_created |= 1<<EBPF_MODULE_CACHESTAT_IDX;
}
em->apps_charts |= NETDATA_EBPF_APPS_FLAG_CHART_CREATED;
}
/*****************************************************************
*
* MAIN LOOP
*
*****************************************************************/
/**
* Read global counter
*
* Read the table with number of calls for all functions
*
* @param stats vector used to read data from control table.
* @param maps_per_core do I need to read all cores?
*/
static void ebpf_cachestat_read_global_tables(netdata_idx_t *stats, int maps_per_core)
{
ebpf_read_global_table_stats(cachestat_hash_values,
cachestat_values,
cachestat_maps[NETDATA_CACHESTAT_GLOBAL_STATS].map_fd,
maps_per_core,
NETDATA_KEY_CALLS_ADD_TO_PAGE_CACHE_LRU,
NETDATA_CACHESTAT_END);
ebpf_read_global_table_stats(stats,
cachestat_values,
cachestat_maps[NETDATA_CACHESTAT_CTRL].map_fd,
maps_per_core,
NETDATA_CONTROLLER_PID_TABLE_ADD,
NETDATA_CONTROLLER_END);
}
/**
* Send global
*
* Send global charts to Netdata
*/
static void cachestat_send_global(netdata_publish_cachestat_t *publish)
{
calculate_stats(publish);
netdata_publish_syscall_t *ptr = cachestat_counter_publish_aggregated;
ebpf_one_dimension_write_charts(
NETDATA_EBPF_MEMORY_GROUP, NETDATA_CACHESTAT_HIT_RATIO_CHART, ptr[NETDATA_CACHESTAT_IDX_RATIO].dimension,
publish->ratio);
ebpf_one_dimension_write_charts(
NETDATA_EBPF_MEMORY_GROUP, NETDATA_CACHESTAT_DIRTY_CHART, ptr[NETDATA_CACHESTAT_IDX_DIRTY].dimension,
(long long)cachestat_hash_values[NETDATA_KEY_CALLS_MARK_BUFFER_DIRTY]);
ebpf_one_dimension_write_charts(
NETDATA_EBPF_MEMORY_GROUP, NETDATA_CACHESTAT_HIT_CHART, ptr[NETDATA_CACHESTAT_IDX_HIT].dimension, publish->hit);
ebpf_one_dimension_write_charts(
NETDATA_EBPF_MEMORY_GROUP, NETDATA_CACHESTAT_MISSES_CHART, ptr[NETDATA_CACHESTAT_IDX_MISS].dimension,
publish->miss);
}
/**
* Send data to Netdata calling auxiliary functions.
*
* @param root the target list.
*/
void ebpf_cache_send_apps_data(struct ebpf_target *root)
{
struct ebpf_target *w;
collected_number value;
pthread_mutex_lock(&collect_data_mutex);
for (w = root; w; w = w->next) {
if (unlikely(!(w->charts_created & (1<<EBPF_MODULE_CACHESTAT_IDX))))
continue;
netdata_cachestat_pid_t *current = &w->cachestat.current;
netdata_cachestat_pid_t *prev = &w->cachestat.prev;
uint64_t mpa = current->mark_page_accessed - prev->mark_page_accessed;
uint64_t mbd = current->mark_buffer_dirty - prev->mark_buffer_dirty;
w->cachestat.dirty = (long long)mbd;
uint64_t apcl = current->add_to_page_cache_lru - prev->add_to_page_cache_lru;
uint64_t apd = current->account_page_dirtied - prev->account_page_dirtied;
cachestat_update_publish(&w->cachestat, mpa, mbd, apcl, apd);
value = (collected_number) w->cachestat.ratio;
ebpf_write_begin_chart(NETDATA_APP_FAMILY, w->clean_name, "_ebpf_cachestat_hit_ratio");
write_chart_dimension("ratio", value);
ebpf_write_end_chart();
value = (collected_number) w->cachestat.dirty;
ebpf_write_begin_chart(NETDATA_APP_FAMILY, w->clean_name, "_ebpf_cachestat_dirty_pages");
write_chart_dimension("pages", value);
ebpf_write_end_chart();
value = (collected_number) w->cachestat.hit;
ebpf_write_begin_chart(NETDATA_APP_FAMILY, w->clean_name, "_ebpf_cachestat_access");
write_chart_dimension("hits", value);
ebpf_write_end_chart();
value = (collected_number) w->cachestat.miss;
ebpf_write_begin_chart(NETDATA_APP_FAMILY, w->clean_name, "_ebpf_cachestat_misses");
write_chart_dimension("misses", value);
ebpf_write_end_chart();
}
pthread_mutex_unlock(&collect_data_mutex);
}
/**
* Cachestat sum PIDs
*
* Sum values for all PIDs associated to a group
*
* @param publish output structure.
* @param root structure with listed IPs
*/
void ebpf_cachestat_sum_cgroup_pids(netdata_publish_cachestat_t *publish, struct pid_on_target2 *root)
{
memcpy(&publish->prev, &publish->current,sizeof(publish->current));
memset(&publish->current, 0, sizeof(publish->current));
netdata_cachestat_pid_t *dst = &publish->current;
while (root) {
netdata_cachestat_pid_t *src = &root->cachestat;
dst->account_page_dirtied += src->account_page_dirtied;
dst->add_to_page_cache_lru += src->add_to_page_cache_lru;
dst->mark_buffer_dirty += src->mark_buffer_dirty;
dst->mark_page_accessed += src->mark_page_accessed;
root = root->next;
}
}
/**
* Calc chart values
*
* Do necessary math to plot charts.
*/
void ebpf_cachestat_calc_chart_values()
{
ebpf_cgroup_target_t *ect;
for (ect = ebpf_cgroup_pids; ect ; ect = ect->next) {
ebpf_cachestat_sum_cgroup_pids(&ect->publish_cachestat, ect->pids);
netdata_cachestat_pid_t *current = &ect->publish_cachestat.current;
netdata_cachestat_pid_t *prev = &ect->publish_cachestat.prev;
uint64_t mpa = current->mark_page_accessed - prev->mark_page_accessed;
uint64_t mbd = current->mark_buffer_dirty - prev->mark_buffer_dirty;
ect->publish_cachestat.dirty = (long long)mbd;
uint64_t apcl = current->add_to_page_cache_lru - prev->add_to_page_cache_lru;
uint64_t apd = current->account_page_dirtied - prev->account_page_dirtied;
cachestat_update_publish(&ect->publish_cachestat, mpa, mbd, apcl, apd);
}
}
/**
* Create Systemd cachestat Charts
*
* Create charts when systemd is enabled
*
* @param update_every value to overwrite the update frequency set by the server.
**/
static void ebpf_create_systemd_cachestat_charts(int update_every)
{
static ebpf_systemd_args_t data_hit_ratio = {
.title = "Hit ratio",
.units = EBPF_COMMON_DIMENSION_PERCENTAGE,
.family = NETDATA_CACHESTAT_SUBMENU,
.charttype = NETDATA_EBPF_CHART_TYPE_LINE,
.order = 21100,
.algorithm = EBPF_CHART_ALGORITHM_ABSOLUTE,
.context = NETDATA_SYSTEMD_CACHESTAT_HIT_RATIO_CONTEXT,
.module = NETDATA_EBPF_MODULE_NAME_CACHESTAT,
.update_every = 0,
.suffix = NETDATA_CACHESTAT_HIT_RATIO_CHART,
.dimension = "percentage"
};
static ebpf_systemd_args_t data_dirty = {
.title = "Number of dirty pages",
.units = EBPF_CACHESTAT_DIMENSION_PAGE,
.family = NETDATA_CACHESTAT_SUBMENU,
.charttype = NETDATA_EBPF_CHART_TYPE_LINE,
.order = 21101,
.algorithm = EBPF_CHART_ALGORITHM_ABSOLUTE,
.context = NETDATA_SYSTEMD_CACHESTAT_MODIFIED_CACHE_CONTEXT,
.module = NETDATA_EBPF_MODULE_NAME_CACHESTAT,
.update_every = 0,
.suffix = NETDATA_CACHESTAT_DIRTY_CHART,
.dimension = "pages"
};
static ebpf_systemd_args_t data_hit = {
.title = "Number of accessed pages",
.units = EBPF_CACHESTAT_DIMENSION_HITS,
.family = NETDATA_CACHESTAT_SUBMENU,
.charttype = NETDATA_EBPF_CHART_TYPE_LINE,
.order = 21102,
.algorithm = EBPF_CHART_ALGORITHM_ABSOLUTE,
.context = NETDATA_SYSTEMD_CACHESTAT_HIT_FILE_CONTEXT,
.module = NETDATA_EBPF_MODULE_NAME_CACHESTAT,
.update_every = 0,
.suffix = NETDATA_CACHESTAT_HIT_CHART,
.dimension = "hits"
};
static ebpf_systemd_args_t data_miss = {
.title = "Files out of page cache",
.units = EBPF_CACHESTAT_DIMENSION_MISSES,
.family = NETDATA_CACHESTAT_SUBMENU,
.charttype = NETDATA_EBPF_CHART_TYPE_LINE,
.order = 21103,
.algorithm = EBPF_CHART_ALGORITHM_ABSOLUTE,
.context = NETDATA_SYSTEMD_CACHESTAT_MISS_FILES_CONTEXT,
.module = NETDATA_EBPF_MODULE_NAME_CACHESTAT,
.update_every = 0,
.suffix = NETDATA_CACHESTAT_MISSES_CHART,
.dimension = "misses"
};
if (!data_miss.update_every)
data_hit_ratio.update_every = data_dirty.update_every =
data_hit.update_every = data_miss.update_every = update_every;
ebpf_cgroup_target_t *w;
for (w = ebpf_cgroup_pids; w; w = w->next) {
if (unlikely(!w->systemd || w->flags & NETDATA_EBPF_SERVICES_HAS_CACHESTAT_CHART))
continue;
data_hit_ratio.id = data_dirty.id = data_hit.id = data_miss.id = w->name;
ebpf_create_charts_on_systemd(&data_hit_ratio);
ebpf_create_charts_on_systemd(&data_dirty);
ebpf_create_charts_on_systemd(&data_hit);
ebpf_create_charts_on_systemd(&data_miss);
w->flags |= NETDATA_EBPF_SERVICES_HAS_CACHESTAT_CHART;
}
}
/**
* Send Cache Stat charts
*
* Send collected data to Netdata.
*/
static void ebpf_send_systemd_cachestat_charts()
{
ebpf_cgroup_target_t *ect;
for (ect = ebpf_cgroup_pids; ect; ect = ect->next) {
if (unlikely(!(ect->flags & NETDATA_EBPF_SERVICES_HAS_CACHESTAT_CHART)) ) {
continue;
}
ebpf_write_begin_chart(NETDATA_SERVICE_FAMILY, ect->name, NETDATA_CACHESTAT_HIT_RATIO_CHART);
write_chart_dimension("percentage", (long long)ect->publish_cachestat.ratio);
ebpf_write_end_chart();
ebpf_write_begin_chart(NETDATA_SERVICE_FAMILY, ect->name, NETDATA_CACHESTAT_DIRTY_CHART);
write_chart_dimension("pages", (long long)ect->publish_cachestat.dirty);
ebpf_write_end_chart();
ebpf_write_begin_chart(NETDATA_SERVICE_FAMILY, ect->name, NETDATA_CACHESTAT_HIT_CHART);
write_chart_dimension("hits", (long long)ect->publish_cachestat.hit);
ebpf_write_end_chart();
ebpf_write_begin_chart(NETDATA_SERVICE_FAMILY, ect->name, NETDATA_CACHESTAT_MISSES_CHART);
write_chart_dimension("misses", (long long)ect->publish_cachestat.miss);
ebpf_write_end_chart();
}
}
/**
* Send Directory Cache charts
*
* Send collected data to Netdata.
*/
static void ebpf_send_specific_cachestat_data(char *type, netdata_publish_cachestat_t *npc)
{
ebpf_write_begin_chart(type, NETDATA_CACHESTAT_HIT_RATIO_CHART, "");
write_chart_dimension(cachestat_counter_publish_aggregated[NETDATA_CACHESTAT_IDX_RATIO].name, (long long)npc->ratio);
ebpf_write_end_chart();
ebpf_write_begin_chart(type, NETDATA_CACHESTAT_DIRTY_CHART, "");
write_chart_dimension(cachestat_counter_publish_aggregated[NETDATA_CACHESTAT_IDX_DIRTY].name, (long long)npc->dirty);
ebpf_write_end_chart();
ebpf_write_begin_chart(type, NETDATA_CACHESTAT_HIT_CHART, "");
write_chart_dimension(cachestat_counter_publish_aggregated[NETDATA_CACHESTAT_IDX_HIT].name, (long long)npc->hit);
ebpf_write_end_chart();
ebpf_write_begin_chart(type, NETDATA_CACHESTAT_MISSES_CHART, "");
write_chart_dimension(cachestat_counter_publish_aggregated[NETDATA_CACHESTAT_IDX_MISS].name, (long long)npc->miss);
ebpf_write_end_chart();
}
/**
* Create specific cache Stat charts
*
* Create charts for cgroup/application.
*
* @param type the chart type.
* @param update_every value to overwrite the update frequency set by the server.
*/
static void ebpf_create_specific_cachestat_charts(char *type, int update_every)
{
char *label = (!strncmp(type, "cgroup_", 7)) ? &type[7] : type;
ebpf_create_chart(type, NETDATA_CACHESTAT_HIT_RATIO_CHART,
"Hit ratio",
EBPF_COMMON_DIMENSION_PERCENTAGE, NETDATA_CACHESTAT_SUBMENU,
NETDATA_CGROUP_CACHESTAT_HIT_RATIO_CONTEXT,
NETDATA_EBPF_CHART_TYPE_LINE, NETDATA_CHART_PRIO_CGROUPS_CONTAINERS + 5200,
ebpf_create_global_dimension,
cachestat_counter_publish_aggregated, 1, update_every, NETDATA_EBPF_MODULE_NAME_CACHESTAT);
ebpf_create_chart_labels("cgroup_name", label, RRDLABEL_SRC_AUTO);
ebpf_commit_label();
ebpf_create_chart(type, NETDATA_CACHESTAT_DIRTY_CHART,
"Number of dirty pages",
EBPF_CACHESTAT_DIMENSION_PAGE, NETDATA_CACHESTAT_SUBMENU,
NETDATA_CGROUP_CACHESTAT_MODIFIED_CACHE_CONTEXT,
NETDATA_EBPF_CHART_TYPE_LINE, NETDATA_CHART_PRIO_CGROUPS_CONTAINERS + 5201,
ebpf_create_global_dimension,
&cachestat_counter_publish_aggregated[NETDATA_CACHESTAT_IDX_DIRTY], 1,
update_every, NETDATA_EBPF_MODULE_NAME_CACHESTAT);
ebpf_create_chart_labels("cgroup_name", label, RRDLABEL_SRC_AUTO);
ebpf_commit_label();
ebpf_create_chart(type, NETDATA_CACHESTAT_HIT_CHART,
"Number of accessed files",
EBPF_CACHESTAT_DIMENSION_HITS, NETDATA_CACHESTAT_SUBMENU,
NETDATA_CGROUP_CACHESTAT_HIT_FILES_CONTEXT,
NETDATA_EBPF_CHART_TYPE_LINE, NETDATA_CHART_PRIO_CGROUPS_CONTAINERS + 5202,
ebpf_create_global_dimension,
&cachestat_counter_publish_aggregated[NETDATA_CACHESTAT_IDX_HIT], 1,
update_every, NETDATA_EBPF_MODULE_NAME_CACHESTAT);
ebpf_create_chart_labels("cgroup_name", label, RRDLABEL_SRC_AUTO);
ebpf_commit_label();
ebpf_create_chart(type, NETDATA_CACHESTAT_MISSES_CHART,
"Files out of page cache",
EBPF_CACHESTAT_DIMENSION_MISSES, NETDATA_CACHESTAT_SUBMENU,
NETDATA_CGROUP_CACHESTAT_MISS_FILES_CONTEXT,
NETDATA_EBPF_CHART_TYPE_LINE, NETDATA_CHART_PRIO_CGROUPS_CONTAINERS + 5203,
ebpf_create_global_dimension,
&cachestat_counter_publish_aggregated[NETDATA_CACHESTAT_IDX_MISS], 1,
update_every, NETDATA_EBPF_MODULE_NAME_CACHESTAT);
ebpf_create_chart_labels("cgroup_name", label, RRDLABEL_SRC_AUTO);
ebpf_commit_label();
}
/**
* Obsolete specific cache stat charts
*
* Obsolete charts for cgroup/application.
*
* @param type the chart type.
* @param update_every value to overwrite the update frequency set by the server.
*/
static void ebpf_obsolete_specific_cachestat_charts(char *type, int update_every)
{
ebpf_write_chart_obsolete(type, NETDATA_CACHESTAT_HIT_RATIO_CHART,
"",
"Hit ratio",
EBPF_COMMON_DIMENSION_PERCENTAGE, NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE, NETDATA_CGROUP_CACHESTAT_HIT_RATIO_CONTEXT,
NETDATA_CHART_PRIO_CGROUPS_CONTAINERS + 5200, update_every);
ebpf_write_chart_obsolete(type, NETDATA_CACHESTAT_DIRTY_CHART,
"",
"Number of dirty pages",
EBPF_CACHESTAT_DIMENSION_PAGE, NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE, NETDATA_CGROUP_CACHESTAT_MODIFIED_CACHE_CONTEXT,
NETDATA_CHART_PRIO_CGROUPS_CONTAINERS + 5201, update_every);
ebpf_write_chart_obsolete(type, NETDATA_CACHESTAT_HIT_CHART,
"",
"Number of accessed files",
EBPF_CACHESTAT_DIMENSION_HITS, NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE, NETDATA_CGROUP_CACHESTAT_HIT_FILES_CONTEXT,
NETDATA_CHART_PRIO_CGROUPS_CONTAINERS + 5202, update_every);
ebpf_write_chart_obsolete(type, NETDATA_CACHESTAT_MISSES_CHART,
"",
"Files out of page cache",
EBPF_CACHESTAT_DIMENSION_MISSES, NETDATA_CACHESTAT_SUBMENU,
NETDATA_EBPF_CHART_TYPE_LINE, NETDATA_CGROUP_CACHESTAT_MISS_FILES_CONTEXT,
NETDATA_CHART_PRIO_CGROUPS_CONTAINERS + 5203, update_every);
}
/**
* Send data to Netdata calling auxiliary functions.
*
* @param update_every value to overwrite the update frequency set by the server.
*/
void ebpf_cachestat_send_cgroup_data(int update_every)
{
pthread_mutex_lock(&mutex_cgroup_shm);
ebpf_cgroup_target_t *ect;
ebpf_cachestat_calc_chart_values();
if (shm_ebpf_cgroup.header->systemd_enabled) {
if (send_cgroup_chart) {
ebpf_create_systemd_cachestat_charts(update_every);
}
ebpf_send_systemd_cachestat_charts();
}
for (ect = ebpf_cgroup_pids; ect ; ect = ect->next) {
if (ect->systemd)
continue;
if (!(ect->flags & NETDATA_EBPF_CGROUP_HAS_CACHESTAT_CHART) && ect->updated) {
ebpf_create_specific_cachestat_charts(ect->name, update_every);
ect->flags |= NETDATA_EBPF_CGROUP_HAS_CACHESTAT_CHART;
}
if (ect->flags & NETDATA_EBPF_CGROUP_HAS_CACHESTAT_CHART) {
if (ect->updated) {
ebpf_send_specific_cachestat_data(ect->name, &ect->publish_cachestat);
} else {
ebpf_obsolete_specific_cachestat_charts(ect->name, update_every);
ect->flags &= ~NETDATA_EBPF_CGROUP_HAS_CACHESTAT_CHART;
}
}
}
pthread_mutex_unlock(&mutex_cgroup_shm);
}
/**
* Main loop for this collector.
*/
static void cachestat_collector(ebpf_module_t *em)
{
netdata_publish_cachestat_t publish;
memset(&publish, 0, sizeof(publish));
int cgroups = em->cgroup_charts;
int update_every = em->update_every;
int maps_per_core = em->maps_per_core;
heartbeat_t hb;
heartbeat_init(&hb);
int counter = update_every - 1;
//This will be cancelled by its parent
uint32_t running_time = 0;
uint32_t lifetime = em->lifetime;
netdata_idx_t *stats = em->hash_table_stats;
memset(stats, 0, sizeof(em->hash_table_stats));
while (!ebpf_plugin_stop() && running_time < lifetime) {
(void)heartbeat_next(&hb, USEC_PER_SEC);
if (ebpf_plugin_stop() || ++counter != update_every)
continue;
counter = 0;
netdata_apps_integration_flags_t apps = em->apps_charts;
ebpf_cachestat_read_global_tables(stats, maps_per_core);
if (cgroups && shm_ebpf_cgroup.header)
ebpf_update_cachestat_cgroup();
pthread_mutex_lock(&lock);
cachestat_send_global(&publish);
if (apps & NETDATA_EBPF_APPS_FLAG_CHART_CREATED)
ebpf_cache_send_apps_data(apps_groups_root_target);
if (cgroups && shm_ebpf_cgroup.header)
ebpf_cachestat_send_cgroup_data(update_every);
pthread_mutex_unlock(&lock);
pthread_mutex_lock(&ebpf_exit_cleanup);
if (running_time && !em->running_time)
running_time = update_every;
else
running_time += update_every;
em->running_time = running_time;
pthread_mutex_unlock(&ebpf_exit_cleanup);
}
}
/*****************************************************************
*
* INITIALIZE THREAD
*
*****************************************************************/
/**
* Create global charts
*
* Call ebpf_create_chart to create the charts for the collector.
*
* @param em a pointer to `struct ebpf_module`
*/
static void ebpf_create_memory_charts(ebpf_module_t *em)
{
ebpf_create_chart(NETDATA_EBPF_MEMORY_GROUP, NETDATA_CACHESTAT_HIT_RATIO_CHART,
"Hit ratio",
EBPF_COMMON_DIMENSION_PERCENTAGE, NETDATA_CACHESTAT_SUBMENU,
NULL,
NETDATA_EBPF_CHART_TYPE_LINE,
21100,
ebpf_create_global_dimension,
cachestat_counter_publish_aggregated, 1, em->update_every, NETDATA_EBPF_MODULE_NAME_CACHESTAT);
ebpf_create_chart(NETDATA_EBPF_MEMORY_GROUP, NETDATA_CACHESTAT_DIRTY_CHART,
"Number of dirty pages",
EBPF_CACHESTAT_DIMENSION_PAGE, NETDATA_CACHESTAT_SUBMENU,
NULL,
NETDATA_EBPF_CHART_TYPE_LINE,
21101,
ebpf_create_global_dimension,
&cachestat_counter_publish_aggregated[NETDATA_CACHESTAT_IDX_DIRTY], 1,
em->update_every, NETDATA_EBPF_MODULE_NAME_CACHESTAT);
ebpf_create_chart(NETDATA_EBPF_MEMORY_GROUP, NETDATA_CACHESTAT_HIT_CHART,
"Number of accessed files",
EBPF_CACHESTAT_DIMENSION_HITS, NETDATA_CACHESTAT_SUBMENU,
NULL,
NETDATA_EBPF_CHART_TYPE_LINE,
21102,
ebpf_create_global_dimension,
&cachestat_counter_publish_aggregated[NETDATA_CACHESTAT_IDX_HIT], 1,
em->update_every, NETDATA_EBPF_MODULE_NAME_CACHESTAT);
ebpf_create_chart(NETDATA_EBPF_MEMORY_GROUP, NETDATA_CACHESTAT_MISSES_CHART,
"Files out of page cache",
EBPF_CACHESTAT_DIMENSION_MISSES, NETDATA_CACHESTAT_SUBMENU,
NULL,
NETDATA_EBPF_CHART_TYPE_LINE,
21103,
ebpf_create_global_dimension,
&cachestat_counter_publish_aggregated[NETDATA_CACHESTAT_IDX_MISS], 1,
em->update_every, NETDATA_EBPF_MODULE_NAME_CACHESTAT);
fflush(stdout);
}
/**
* Allocate vectors used with this thread.
*
* We are not testing the return, because callocz does this and shutdown the software
* case it was not possible to allocate.
*/
static void ebpf_cachestat_allocate_global_vectors()
{
cachestat_vector = callocz((size_t)ebpf_nprocs, sizeof(netdata_cachestat_pid_t));
cachestat_values = callocz((size_t)ebpf_nprocs, sizeof(netdata_idx_t));
memset(cachestat_hash_values, 0, NETDATA_CACHESTAT_END * sizeof(netdata_idx_t));
memset(cachestat_counter_aggregated_data, 0, NETDATA_CACHESTAT_END * sizeof(netdata_syscall_stat_t));
memset(cachestat_counter_publish_aggregated, 0, NETDATA_CACHESTAT_END * sizeof(netdata_publish_syscall_t));
}
/*****************************************************************
*
* MAIN THREAD
*
*****************************************************************/
/**
* Update Internal value
*
* Update values used during runtime.
*
* @return It returns 0 when one of the functions is present and -1 otherwise.
*/
static int ebpf_cachestat_set_internal_value()
{
ebpf_addresses_t address = {.function = NULL, .hash = 0, .addr = 0};
int i;
for (i = 0; i < NETDATA_CACHESTAT_ACCOUNT_DIRTY_END ; i++) {
address.function = account_page[i];
ebpf_load_addresses(&address, -1);
if (address.addr)
break;
}
if (!address.addr) {
netdata_log_error("%s cachestat.", NETDATA_EBPF_DEFAULT_FNT_NOT_FOUND);
return -1;
}
cachestat_targets[NETDATA_KEY_CALLS_ACCOUNT_PAGE_DIRTIED].name = address.function;
return 0;
}
/*
* Load BPF
*
* Load BPF files.
*
* @param em the structure with configuration
*/
static int ebpf_cachestat_load_bpf(ebpf_module_t *em)
{
#ifdef LIBBPF_MAJOR_VERSION
ebpf_define_map_type(cachestat_maps, em->maps_per_core, running_on_kernel);
#endif
int ret = 0;
ebpf_adjust_apps_cgroup(em, em->targets[NETDATA_KEY_CALLS_ADD_TO_PAGE_CACHE_LRU].mode);
if (em->load & EBPF_LOAD_LEGACY) {
em->probe_links = ebpf_load_program(ebpf_plugin_dir, em, running_on_kernel, isrh, &em->objects);
if (!em->probe_links) {
ret = -1;
}
}
#ifdef LIBBPF_MAJOR_VERSION
else {
cachestat_bpf_obj = cachestat_bpf__open();
if (!cachestat_bpf_obj)
ret = -1;
else
ret = ebpf_cachestat_load_and_attach(cachestat_bpf_obj, em);
}
#endif
if (ret)
netdata_log_error("%s %s", EBPF_DEFAULT_ERROR_MSG, em->info.thread_name);
return ret;
}
/**
* Cachestat thread
*
* Thread used to make cachestat thread
*
* @param ptr a pointer to `struct ebpf_module`
*
* @return It always return NULL
*/
void *ebpf_cachestat_thread(void *ptr)
{
ebpf_module_t *em = (ebpf_module_t *)ptr;
CLEANUP_FUNCTION_REGISTER(ebpf_cachestat_exit) cleanup_ptr = em;
em->maps = cachestat_maps;
ebpf_update_pid_table(&cachestat_maps[NETDATA_CACHESTAT_PID_STATS], em);
if (ebpf_cachestat_set_internal_value()) {
goto endcachestat;
}
#ifdef LIBBPF_MAJOR_VERSION
ebpf_adjust_thread_load(em, default_btf);
#endif
if (ebpf_cachestat_load_bpf(em)) {
goto endcachestat;
}
ebpf_cachestat_allocate_global_vectors();
int algorithms[NETDATA_CACHESTAT_END] = {
NETDATA_EBPF_ABSOLUTE_IDX, NETDATA_EBPF_INCREMENTAL_IDX, NETDATA_EBPF_ABSOLUTE_IDX, NETDATA_EBPF_ABSOLUTE_IDX
};
ebpf_global_labels(cachestat_counter_aggregated_data, cachestat_counter_publish_aggregated,
cachestat_counter_dimension_name, cachestat_counter_dimension_name,
algorithms, NETDATA_CACHESTAT_END);
pthread_mutex_lock(&lock);
ebpf_update_stats(&plugin_statistics, em);
ebpf_update_kernel_memory_with_vector(&plugin_statistics, em->maps, EBPF_ACTION_STAT_ADD);
ebpf_create_memory_charts(em);
pthread_mutex_unlock(&lock);
ebpf_read_cachestat.thread = nd_thread_create(
ebpf_read_cachestat.name,
NETDATA_THREAD_OPTION_DEFAULT,
ebpf_read_cachestat_thread,
em);
cachestat_collector(em);
endcachestat:
ebpf_update_disabled_plugin_stats(em);
return NULL;
}