path: root/tools/mm/slabinfo.c

// SPDX-License-Identifier: GPL-2.0
/*
 * Slabinfo: Tool to get reports about slabs
 *
 * (C) 2007 sgi, Christoph Lameter
 * (C) 2011 Linux Foundation, Christoph Lameter
 *
 * Compile with:
 *
 * gcc -o slabinfo slabinfo.c
 */
#include <stdio.h>
#include <stdlib.h>
#include <sys/types.h>
#include <dirent.h>
#include <strings.h>
#include <string.h>
#include <unistd.h>
#include <stdarg.h>
#include <getopt.h>
#include <regex.h>
#include <errno.h>

#define MAX_SLABS 2000
#define MAX_ALIASES 500
#define MAX_NODES 1024

struct slabinfo {
	char *name;
	int alias;
	int refs;
	int aliases, align, cache_dma, cpu_slabs, destroy_by_rcu;
	unsigned int hwcache_align, object_size, objs_per_slab;
	unsigned int sanity_checks, slab_size, store_user, trace;
	int order, poison, reclaim_account, red_zone;
	unsigned long partial, objects, slabs, objects_partial, objects_total;
	unsigned long alloc_fastpath, alloc_slowpath;
	unsigned long free_fastpath, free_slowpath;
	unsigned long free_frozen, free_add_partial, free_remove_partial;
	unsigned long alloc_from_partial, alloc_slab, free_slab, alloc_refill;
	unsigned long cpuslab_flush, deactivate_full, deactivate_empty;
	unsigned long deactivate_to_head, deactivate_to_tail;
	unsigned long deactivate_remote_frees, order_fallback;
	unsigned long cmpxchg_double_cpu_fail, cmpxchg_double_fail;
	unsigned long alloc_node_mismatch, deactivate_bypass;
	unsigned long cpu_partial_alloc, cpu_partial_free;
	int numa[MAX_NODES];
	int numa_partial[MAX_NODES];
} slabinfo[MAX_SLABS];

struct aliasinfo {
	char *name;
	char *ref;
	struct slabinfo *slab;
} aliasinfo[MAX_ALIASES];

int slabs;
int actual_slabs;
int aliases;
int alias_targets;
int highest_node;

char buffer[4096];

int show_empty;
int show_report;
int show_alias;
int show_slab;
int skip_zero = 1;
int show_numa;
int show_track;
int show_first_alias;
int validate;
int shrink;
int show_inverted;
int show_single_ref;
int show_totals;
int sort_size;
int sort_active;
int set_debug;
int show_ops;
int sort_partial;
int show_activity;
int output_lines = -1;
int sort_loss;
int extended_totals;
int show_bytes;
int unreclaim_only;

/* Debug options */
int sanity;
int redzone;
int poison;
int tracking;
int tracing;

int page_size;

regex_t pattern;

static void fatal(const char *x, ...)
{
	va_list ap;

	va_start(ap, x);
	vfprintf(stderr, x, ap);
	va_end(ap);
	exit(EXIT_FAILURE);
}

static void usage(void)
{
	printf("slabinfo 4/15/2011. (c) 2007 sgi/(c) 2011 Linux Foundation.\n\n"
		"slabinfo [-aABDefhilLnoPrsStTUvXz1] [N=K] [-dafzput] [slab-regexp]\n"
		"-a|--aliases           Show aliases\n"
		"-A|--activity          Most active slabs first\n"
		"-B|--Bytes             Show size in bytes\n"
		"-D|--display-active    Switch line format to activity\n"
		"-e|--empty             Show empty slabs\n"
		"-f|--first-alias       Show first alias\n"
		"-h|--help              Show usage information\n"
		"-i|--inverted          Inverted list\n"
		"-l|--slabs             Show slabs\n"
		"-L|--Loss              Sort by loss\n"
		"-n|--numa              Show NUMA information\n"
		"-N|--lines=K           Show the first K slabs\n"
		"-o|--ops               Show kmem_cache_ops\n"
		"-P|--partial           Sort by number of partial slabs\n"
		"-r|--report            Detailed report on single slabs\n"
		"-s|--shrink            Shrink slabs\n"
		"-S|--Size              Sort by size\n"
		"-t|--tracking          Show alloc/free information\n"
		"-T|--Totals            Show summary information\n"
		"-U|--Unreclaim         Show unreclaimable slabs only\n"
		"-v|--validate          Validate slabs\n"
		"-X|--Xtotals           Show extended summary information\n"
		"-z|--zero              Include empty slabs\n"
		"-1|--1ref              Single reference\n"

		"\n"
		"-d  | --debug          Switch off all debug options\n"
		"-da | --debug=a        Switch on all debug options (--debug=FZPU)\n"

		"\n"
		"-d[afzput] | --debug=[afzput]\n"
		"    f | F              Sanity Checks (SLAB_CONSISTENCY_CHECKS)\n"
		"    z | Z              Redzoning\n"
		"    p | P              Poisoning\n"
		"    u | U              Tracking\n"
		"    t | T              Tracing\n"

		"\nSorting options (--Loss, --Size, --Partial) are mutually exclusive\n"
	);
}

static unsigned long read_obj(const char *name)
{
	FILE *f = fopen(name, "r");

	if (!f) {
		buffer[0] = 0;
		if (errno == EACCES)
			fatal("%s, Try using superuser\n", strerror(errno));
	} else {
		if (!fgets(buffer, sizeof(buffer), f))
			buffer[0] = 0;
		fclose(f);
		if (buffer[strlen(buffer)] == '\n')
			buffer[strlen(buffer)] = 0;
	}
	return strlen(buffer);
}


/*
 * Get the contents of an attribute
 */
static unsigned long get_obj(const char *name)
{
	if (!read_obj(name))
		return 0;

	return atol(buffer);
}

static unsigned long get_obj_and_str(const char *name, char **x)
{
	unsigned long result = 0;
	char *p;

	*x = NULL;

	if (!read_obj(name)) {
		x = NULL;
		return 0;
	}
	result = strtoul(buffer, &p, 10);
	while (*p == ' ')
		p++;
	if (*p)
		*x = strdup(p);
	return result;
}

static void set_obj(struct slabinfo *s, const char *name, int n)
{
	char x[100];
	FILE *f;

	snprintf(x, 100, "%s/%s", s->name, name);
	f = fopen(x, "w");
	if (!f)
		fatal("Cannot write to %s\n", x);

	fprintf(f, "%d\n", n);
	fclose(f);
}

static unsigned long read_slab_obj(struct slabinfo *s, const char *name)
{
	char x[100];
	FILE *f;
	size_t l;

	snprintf(x, 100, "%s/%s", s->name, name);
	f = fopen(x, "r");
	if (!f) {
		buffer[0] = 0;
		l = 0;
	} else {
		l = fread(buffer, 1, sizeof(buffer), f);
		buffer[l] = 0;
		fclose(f);
	}
	return l;
}

static unsigned long read_debug_slab_obj(struct slabinfo *s, const char *name)
{
	char x[128];
	FILE *f;
	size_t l;

	snprintf(x, 128, "/sys/kernel/debug/slab/%s/%s", s->name, name);
	f = fopen(x, "r");
	if (!f) {
		buffer[0] = 0;
		l = 0;
	} else {
		l = fread(buffer, 1, sizeof(buffer), f);
		buffer[l] = 0;
		fclose(f);
	}
	return l;
}

/*
 * Put a size string together
 */
static int store_size(char *buffer, unsigned long value)
{
	unsigned long divisor = 1;
	char trailer = 0;
	int n;

	if (!show_bytes) {
		if (value > 1000000000UL) {
			divisor = 100000000UL;
			trailer = 'G';
		} else if (value > 1000000UL) {
			divisor = 100000UL;
			trailer = 'M';
		} else if (value > 1000UL) {
			divisor = 100;
			trailer = 'K';
		}
	}

	value /= divisor;
	n = sprintf(buffer, "%ld",value);
	if (trailer) {
		buffer[n] = trailer;
		n++;
		buffer[n] = 0;
	}
	if (divisor != 1) {
		memmove(buffer + n - 2, buffer + n - 3, 4);
		buffer[n-2] = '.';
		n++;
	}
	return n;
}

static void decode_numa_list(int *numa, char *t)
{
	int node;
	int nr;

	memset(numa, 0, MAX_NODES * sizeof(int));

	if (!t)
		return;

	while (*t == 'N') {
		t++;
		node = strtoul(t, &t, 10);
		if (*t == '=') {
			t++;
			nr = strtoul(t, &t, 10);
			numa[node] = nr;
			if (node > highest_node)
				highest_node = node;
		}
		while (*t == ' ')
			t++;
	}
}

static void slab_validate(struct slabinfo *s)
{
	if (strcmp(s->name, "*") == 0)
		return;

	set_obj(s, "validate", 1);
}

static void slab_shrink(struct slabinfo *s)
{
	if (strcmp(s->name, "*") == 0)
		return;

	set_obj(s, "shrink", 1);
}

int line = 0;

static void first_line(void)
{
	if (show_activity)
		printf("Name                   Objects      Alloc       Free"
			"   %%Fast Fallb O CmpX   UL\n");
	else
		printf("Name                   Objects Objsize           %s "
			"Slabs/Part/Cpu  O/S O %%Fr %%Ef Flg