diff options
Diffstat (limited to 'collectors/slabinfo.plugin')
| -rw-r--r-- | collectors/slabinfo.plugin/Makefile.am | 14 | ||||
| l--------- | collectors/slabinfo.plugin/README.md | 1 | ||||
| -rw-r--r-- | collectors/slabinfo.plugin/integrations/linux_kernel_slab_allocator_statistics.md | 131 | ||||
| -rw-r--r-- | collectors/slabinfo.plugin/metadata.yaml | 108 | ||||
| -rw-r--r-- | collectors/slabinfo.plugin/slabinfo.c | 393 |
5 files changed, 647 insertions, 0 deletions
diff --git a/collectors/slabinfo.plugin/Makefile.am b/collectors/slabinfo.plugin/Makefile.am new file mode 100644 index 00000000..07796ea7 --- /dev/null +++ b/collectors/slabinfo.plugin/Makefile.am @@ -0,0 +1,14 @@ +# SPDX-License-Identifier: GPL-3.0-or-later + +AUTOMAKE_OPTIONS = subdir-objects +MAINTAINERCLEANFILES = $(srcdir)/Makefile.in +CLEANFILES = \ + slabinfo.plugin \ + $(NULL) + +include $(top_srcdir)/build/subst.inc +SUFFIXES = .in + +dist_noinst_DATA = \ + README.md \ + $(NULL) diff --git a/collectors/slabinfo.plugin/README.md b/collectors/slabinfo.plugin/README.md new file mode 120000 index 00000000..4d4629a7 --- /dev/null +++ b/collectors/slabinfo.plugin/README.md @@ -0,0 +1 @@ +integrations/linux_kernel_slab_allocator_statistics.md
\ No newline at end of file diff --git a/collectors/slabinfo.plugin/integrations/linux_kernel_slab_allocator_statistics.md b/collectors/slabinfo.plugin/integrations/linux_kernel_slab_allocator_statistics.md new file mode 100644 index 00000000..ce811527 --- /dev/null +++ b/collectors/slabinfo.plugin/integrations/linux_kernel_slab_allocator_statistics.md @@ -0,0 +1,131 @@ +<!--startmeta +custom_edit_url: "https://github.com/netdata/netdata/edit/master/collectors/slabinfo.plugin/README.md" +meta_yaml: "https://github.com/netdata/netdata/edit/master/collectors/slabinfo.plugin/metadata.yaml" +sidebar_label: "Linux kernel SLAB allocator statistics" +learn_status: "Published" +learn_rel_path: "Data Collection/Linux Systems/Kernel" +most_popular: False +message: "DO NOT EDIT THIS FILE DIRECTLY, IT IS GENERATED BY THE COLLECTOR'S metadata.yaml FILE" +endmeta--> + +# Linux kernel SLAB allocator statistics + + +<img src="https://netdata.cloud/img/linuxserver.svg" width="150"/> + + +Plugin: slabinfo.plugin +Module: slabinfo.plugin + +<img src="https://img.shields.io/badge/maintained%20by-Netdata-%2300ab44" /> + +## Overview + +Collects metrics on kernel SLAB cache utilization to monitor the low-level performance impact of workloads in the kernel. + + +The plugin parses `/proc/slabinfo` + +This collector is only supported on the following platforms: + +- Linux + +This collector only supports collecting metrics from a single instance of this integration. + +This integration requires read access to `/proc/slabinfo`, which is accessible only to the root user by default. Netdata uses Linux Capabilities to give the plugin access to this file. `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 sVko that it runs as root. + + +### Default Behavior + +#### Auto-Detection + +Due to the large number of metrics generated by this integration, it is disabled by default and must be manually enabled inside `/etc/netdata/netdata.conf` + + +#### Limits + +The default configuration for this integration does not impose any limits on data collection. + +#### Performance Impact + +The default configuration for this integration is not expected to impose a significant performance impact on the system. + + +## Metrics + +Metrics grouped by *scope*. + +The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels. + +SLAB cache utilization metrics for the whole system. + +### Per Linux kernel SLAB allocator statistics instance + + + +This scope has no labels. + +Metrics: + +| Metric | Dimensions | Unit | +|:------|:----------|:----| +| mem.slabmemory | a dimension per cache | B | +| mem.slabfilling | a dimension per cache | % | +| mem.slabwaste | a dimension per cache | B | + + + +## Alerts + +There are no alerts configured by default for this integration. + + +## Setup + +### Prerequisites + +#### Minimum setup + +If you installed `netdata` using a package manager, it is also necessary to install the package `netdata-plugin-slabinfo`. + + +### Configuration + +#### File + +The configuration file name for this integration is `netdata.conf`. +Configuration for this specific integration is located in the `[plugins]` section within that file. + +The file format is a modified INI syntax. The general structure is: + +```ini +[section1] + option1 = some value + option2 = some other value + +[section2] + option3 = some third value +``` +You can edit the configuration file using the `edit-config` script from the +Netdata [config directory](https://github.com/netdata/netdata/blob/master/docs/configure/nodes.md#the-netdata-config-directory). + +```bash +cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata +sudo ./edit-config netdata.conf +``` +#### Options + + + +<details><summary>The main configuration file.</summary> + +| Name | Description | Default | Required | +|:----|:-----------|:-------|:--------:| +| Enable plugin | As described above plugin is disabled by default, this option is used to enable plugin. | no | yes | + +</details> + +#### Examples +There are no configuration examples. + + diff --git a/collectors/slabinfo.plugin/metadata.yaml b/collectors/slabinfo.plugin/metadata.yaml new file mode 100644 index 00000000..f1977829 --- /dev/null +++ b/collectors/slabinfo.plugin/metadata.yaml @@ -0,0 +1,108 @@ +plugin_name: slabinfo.plugin +modules: + - meta: + plugin_name: slabinfo.plugin + module_name: slabinfo.plugin + monitored_instance: + name: Linux kernel SLAB allocator statistics + link: "https://kernel.org/" + categories: + - data-collection.linux-systems.kernel-metrics + icon_filename: 'linuxserver.svg' + related_resources: + integrations: + list: [] + info_provided_to_referring_integrations: + description: "" + keywords: + - linux kernel + - slab + - slub + - slob + - slabinfo + most_popular: false + overview: + data_collection: + metrics_description: > + Collects metrics on kernel SLAB cache utilization to monitor the low-level performance impact of workloads + in the kernel. + method_description: "The plugin parses `/proc/slabinfo`" + supported_platforms: + include: + - Linux + exclude: [] + multi_instance: false + additional_permissions: + description: > + This integration requires read access to `/proc/slabinfo`, which is accessible only to the root user by + default. Netdata uses Linux Capabilities to give the plugin access to this file. `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 sVko that it runs as root. + default_behavior: + auto_detection: + description: > + Due to the large number of metrics generated by this integration, it is disabled by default and must be + manually enabled inside `/etc/netdata/netdata.conf` + limits: + description: "" + performance_impact: + description: "" + setup: + prerequisites: + list: + - title: Minimum setup + description: "If you installed `netdata` using a package manager, it is also necessary to install the package `netdata-plugin-slabinfo`." + configuration: + file: + name: "netdata.conf" + section_name: "[plugins]" + description: "The main configuration file." + options: + description: "" + folding: + title: "The main configuration file." + enabled: true + list: + - name: Enable plugin + description: As described above plugin is disabled by default, this option is used to enable plugin. + default_value: no + required: true + examples: + folding: + enabled: true + title: "" + list: [] + troubleshooting: + problems: + list: [] + alerts: [] + metrics: + folding: + title: Metrics + enabled: false + description: "SLAB cache utilization metrics for the whole system." + availability: [] + scopes: + - name: global + description: "" + labels: [] + metrics: + - name: mem.slabmemory + description: Memory Usage + unit: "B" + chart_type: line + dimensions: + - name: a dimension per cache + - name: mem.slabfilling + description: Object Filling + unit: "%" + chart_type: line + dimensions: + - name: a dimension per cache + - name: mem.slabwaste + description: Memory waste + unit: "B" + chart_type: line + dimensions: + - name: a dimension per cache diff --git a/collectors/slabinfo.plugin/slabinfo.c b/collectors/slabinfo.plugin/slabinfo.c new file mode 100644 index 00000000..9b9119a6 --- /dev/null +++ b/collectors/slabinfo.plugin/slabinfo.c @@ -0,0 +1,393 @@ +// SPDX-License-Identifier: GPL-3.0-or-later + +#include "daemon/common.h" +#include "libnetdata/required_dummies.h" + +#define PLUGIN_SLABINFO_NAME "slabinfo.plugin" +#define PLUGIN_SLABINFO_PROCFILE "/proc/slabinfo" + +#define CHART_TYPE "mem" +#define CHART_FAMILY "slab" +#define CHART_PRIO 3000 + +// #define slabdebug(...) if (debug) { fprintf(stderr, __VA_ARGS__); } +#define slabdebug(args...) if (debug) { \ + fprintf(stderr, "slabinfo.plugin DEBUG (%04d@%-10.10s:%-15.15s)::", __LINE__, __FILE__, __FUNCTION__); \ + fprintf(stderr, ##args); \ + fprintf(stderr, "\n"); } + +int running = 1; +int debug = 0; +size_t lines_discovered = 0; +int redraw_chart = 0; + +// ---------------------------------------------------------------------------- + +// Slabinfo format : +// format 2.1 Was provided by 57ed3eda977a215f054102b460ab0eb5d8d112e6 (2.6.24-rc6) as: +// seq_puts(m, "# name <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab>"); +// seq_puts(m, " : tunables <limit> <batchcount> <sharedfactor>"); +// seq_puts(m, " : slabdata <active_slabs> <num_slabs> <sharedavail>"); +// +// With max values: +// seq_printf(m, "%-17s %6lu %6lu %6u %4u %4d", +// cache_name(s), sinfo.active_objs, sinfo.num_objs, s->size, sinfo.objects_per_slab, (1 << sinfo.cache_order)); +// seq_printf(m, " : tunables %4u %4u %4u", +// sinfo.limit, sinfo.batchcount, sinfo.shared); +// seq_printf(m, " : slabdata %6lu %6lu %6lu", +// sinfo.active_slabs, sinfo.num_slabs, sinfo.shared_avail); +// +// If CONFIG_DEBUG_SLAB is set, it will also add columns from slabinfo_show_stats (for SLAB only): +// seq_printf(m, " : globalstat %7lu %6lu %5lu %4lu %4lu %4lu %4lu %4lu %4lu", +// allocs, high, grown, reaped, errors, max_freeable, node_allocs, node_frees, overflows); +// seq_printf(m, " : cpustat %6lu %6lu %6lu %6lu", +// allochit, allocmiss, freehit, freemiss); +// +// Implementation choices: +// - Iterates through a linked list of kmem_cache. +// - Name is a char* from struct kmem_cache (mm/slab.h). +// - max name size found is 24: +// grep -roP 'kmem_cache_create\(".+"'| awk '{split($0,a,"\""); print a[2],length(a[2]); }' | sort -k2 -n +// - Using uint64 everywhere, as types fits and allows to use standard helpers + +struct slabinfo { + // procfile fields + const char *name; + uint64_t active_objs; + uint64_t num_objs; + uint64_t obj_size; + uint64_t obj_per_slab; + uint64_t pages_per_slab; + uint64_t tune_limit; + uint64_t tune_batchcnt; + uint64_t tune_shared_factor; + uint64_t data_active_slabs; + uint64_t data_num_slabs; + uint64_t data_shared_avail; + + // Calculated fields + uint64_t mem_usage; + uint64_t mem_waste; + uint8_t obj_filling; + + uint32_t hash; + struct slabinfo *next; +} *slabinfo_root = NULL, *slabinfo_next = NULL, *slabinfo_last_used = NULL; + +// The code is very inspired from "proc_net_dev.c" and "perf_plugin.c" + +// Get the existing object, or create a new one +static struct slabinfo *get_slabstruct(const char *name) { + struct slabinfo *s; + + slabdebug("--> Requested slabstruct %s", name); + + uint32_t hash = simple_hash(name); + + // Search it, from the next to the end + for (s = slabinfo_next; s; s = s->next) { + if ((hash = s->hash) && !strcmp(name, s->name)) { + slabdebug("<-- Found existing slabstruct after %s", slabinfo_last_used->name); + // Prepare the next run + slabinfo_next = s->next; + slabinfo_last_used = s; + return s; + } + } + + // Search it from the beginning to the last position we used + for (s = slabinfo_root; s != slabinfo_last_used; s = s->next) { + if (hash == s->hash && !strcmp(name, s->name)) { + slabdebug("<-- Found existing slabstruct after root %s", slabinfo_root->name); + slabinfo_next = s->next; + slabinfo_last_used = s; + return s; + } + } + + // Create a new one + s = callocz(1, sizeof(struct slabinfo)); + s->name = strdupz(name); + s->hash = hash; + + // Add it to the current position + if (slabinfo_root) { + slabdebug("<-- Creating new slabstruct after %s", slabinfo_last_used->name); + s->next = slabinfo_last_used->next; + slabinfo_last_used->next = s; + slabinfo_last_used = s; + } + else { + slabdebug("<-- Creating new slabstruct as root"); + slabinfo_root = slabinfo_last_used = s; + } + + return s; +} + + +// Read a full pass of slabinfo to update the structs +struct slabinfo *read_file_slabinfo() { + + slabdebug("-> Reading procfile %s", PLUGIN_SLABINFO_PROCFILE); + + static procfile *ff = NULL; + static long slab_pagesize = 0; + + if (unlikely(!slab_pagesize)) { + slab_pagesize = sysconf(_SC_PAGESIZE); + slabdebug(" Discovered pagesize: %ld", slab_pagesize); + } + + if(unlikely(!ff)) { + ff = procfile_reopen(ff, PLUGIN_SLABINFO_PROCFILE, " ,:" , PROCFILE_FLAG_DEFAULT); + if(unlikely(!ff)) { + collector_error("<- Cannot open file '%s", PLUGIN_SLABINFO_PROCFILE); + exit(1); + } + } + + ff = procfile_readall(ff); + if(unlikely(!ff)) { + collector_error("<- Cannot read file '%s'", PLUGIN_SLABINFO_PROCFILE); + exit(0); + } + + + // Iterate on all lines to populate / update the slabinfo struct + size_t lines = procfile_lines(ff), l; + if (unlikely(lines != lines_discovered)) { + lines_discovered = lines; + redraw_chart = 1; + } + + slabdebug(" Read %lu lines from procfile", (unsigned long)lines); + for(l = 2; l < lines; l++) { + if (unlikely(procfile_linewords(ff, l) < 14)) { + slabdebug(" Line %zu has only %zu words, skipping", l, procfile_linewords(ff,l)); + continue; + } + + char *name = procfile_lineword(ff, l, 0); + struct slabinfo *s = get_slabstruct(name); + + s->active_objs = str2uint64_t(procfile_lineword(ff, l, 1), NULL); + s->num_objs = str2uint64_t(procfile_lineword(ff, l, 2), NULL); + s->obj_size = str2uint64_t(procfile_lineword(ff, l, 3), NULL); + s->obj_per_slab = str2uint64_t(procfile_lineword(ff, l, 4), NULL); + s->pages_per_slab = str2uint64_t(procfile_lineword(ff, l, 5), NULL); + + s->tune_limit = str2uint64_t(procfile_lineword(ff, l, 7), NULL); + s->tune_batchcnt = str2uint64_t(procfile_lineword(ff, l, 8), NULL); + s->tune_shared_factor = str2uint64_t(procfile_lineword(ff, l, 9), NULL); + + s->data_active_slabs = str2uint64_t(procfile_lineword(ff, l, 11), NULL); + s->data_num_slabs = str2uint64_t(procfile_lineword(ff, l, 12), NULL); + s->data_shared_avail = str2uint64_t(procfile_lineword(ff, l, 13), NULL); + + uint32_t memperslab = s->pages_per_slab * slab_pagesize; + // Internal fragmentation: loss per slab, due to objects not being a multiple of pagesize + //uint32_t lossperslab = memperslab - s->obj_per_slab * s->obj_size; + + // Total usage = slabs * pages per slab * page size + s->mem_usage = (uint64_t)(s->data_num_slabs * memperslab); + + // Wasted memory (filling): slabs allocated but not filled: sum total slab - sum total objects + s->mem_waste = s->mem_usage - (uint64_t)(s->active_objs * s->obj_size); + //if (s->data_num_slabs > 1) + // s->mem_waste += s->data_num_slabs * lossperslab; + + + // Slab filling efficiency + if (s->num_objs > 0) + s->obj_filling = 100 * s->active_objs / s->num_objs; + else + s->obj_filling = 0; + + slabdebug(" Updated slab %s: %"PRIu64" %"PRIu64" %"PRIu64" %"PRIu64" %"PRIu64" / %"PRIu64" %"PRIu64" %"PRIu64" / %"PRIu64" %"PRIu64" %"PRIu64" / %"PRIu64" %"PRIu64" %hhu", + name, s->active_objs, s->num_objs, s->obj_size, s->obj_per_slab, s->pages_per_slab, + s->tune_limit, s->tune_batchcnt, s->tune_shared_factor, + s->data_active_slabs, s->data_num_slabs, s->data_shared_avail, + s->mem_usage, s->mem_waste, s->obj_filling); + } + + return slabinfo_root; +} + + + +unsigned int do_slab_stats(int update_every) { + + static unsigned int loops = 0; + struct slabinfo *sactive = NULL, *s = NULL; + + // Main processing loop + while (running) { + + sactive = read_file_slabinfo(); + + // Init Charts + if (unlikely(redraw_chart)) { + redraw_chart = 0; + // Memory Usage + printf("CHART %s.%s '' 'Memory Usage' 'B' '%s' '' line %d %d %s\n" + , CHART_TYPE + , "slabmemory" + , CHART_FAMILY + , CHART_PRIO + , update_every + , PLUGIN_SLABINFO_NAME + ); + for (s = sactive; s; s = s->next) { + printf("DIMENSION %s '' absolute 1 1\n", s->name); + } + + // Slab active usage (filling) + printf("CHART %s.%s '' 'Object Filling' '%%' '%s' '' line %d %d %s\n" + , CHART_TYPE + , "slabfilling" + , CHART_FAMILY + , CHART_PRIO + 1 + , update_every + , PLUGIN_SLABINFO_NAME + ); + for (s = sactive; s; s = s->next) { + printf("DIMENSION %s '' absolute 1 1\n", s->name); + } + + // Memory waste + printf("CHART %s.%s '' 'Memory waste' 'B' '%s' '' line %d %d %s\n" + , CHART_TYPE + , "slabwaste" + , CHART_FAMILY + , CHART_PRIO + 2 + , update_every + , PLUGIN_SLABINFO_NAME + ); + for (s = sactive; s; s = s->next) { + printf("DIMENSION %s '' absolute 1 1\n", s->name); + } + } + + + // + // Memory usage + // + printf("BEGIN %s.%s\n" + , CHART_TYPE + , "slabmemory" + ); + for (s = sactive; s; s = s->next) { + printf("SET %s = %"PRIu64"\n" + , s->name + , s->mem_usage + ); + } + printf("END\n"); + + // + // Slab active usage + // + printf("BEGIN %s.%s\n" + , CHART_TYPE + , "slabfilling" + ); + for (s = sactive; s; s = s->next) { + printf("SET %s = %u\n" + , s->name + , s->obj_filling + ); + } + printf("END\n"); + + // + // Memory waste + // + printf("BEGIN %s.%s\n" + , CHART_TYPE + , "slabwaste" + ); + for (s = sactive; s; s = s->next) { + printf("SET %s = %"PRIu64"\n" + , s->name + , s->mem_waste + ); + } + printf("END\n"); + + + loops++; + + sleep(update_every); + } + + return loops; +} + + + + +// ---------------------------------------------------------------------------- +// main + +void usage(void) { + fprintf(stderr, "%s\n", program_name); + exit(1); +} + +int main(int argc, char **argv) { + clocks_init(); + nd_log_initialize_for_external_plugins("slabinfo.plugin"); + + program_name = argv[0]; + program_version = "0.1"; + + int update_every = 1, i, n, freq = 0; + + for (i = 1; i < argc; i++) { + // Frequency parsing + if(isdigit(*argv[i]) && !freq) { + n = (int) str2l(argv[i]); + if (n > 0) { + if (n >= UPDATE_EVERY_MAX) { + collector_error("Invalid interval value: %s", argv[i]); + exit(1); + } + freq = n; + } + } + else if (strcmp("debug", argv[i]) == 0) { + debug = 1; + continue; + } + else { + fprintf(stderr, + "netdata slabinfo.plugin %s\n" + "This program is a data collector plugin for netdata.\n" + "\n" + "Available command line options:\n" + "\n" + " COLLECTION_FREQUENCY data collection frequency in seconds\n" + " minimum: %d\n" + "\n" + " debug enable verbose output\n" + " default: disabled\n" + "\n", + program_version, + update_every + ); + exit(1); + } + } + + if(freq >= update_every) + update_every = freq; + else if(freq) + collector_error("update frequency %d seconds is too small for slabinfo. Using %d.", freq, update_every); + + + // Call the main function. Time drift to be added + do_slab_stats(update_every); + + return 0; +} |