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/*
* Copyright (C) 2006, Intel Corporation
* Copyright (C) 2012, Neil Horman <nhorman@tuxdriver.com>
*
* This file is part of irqbalance
*
* This program file is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program in a file named COPYING; if not, write to the
* Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301 USA
*/
#include "config.h"
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdint.h>
#include <string.h>
#include <syslog.h>
#include <ctype.h>
#include <errno.h>
#include "cpumask.h"
#include "irqbalance.h"
#ifdef AARCH64
#include <sys/types.h>
#include <regex.h>
#include <dirent.h>
#endif
#define LINESIZE 4096
static int proc_int_has_msi = 0;
static int msi_found_in_sysfs = 0;
#ifdef AARCH64
struct irq_match {
char *matchstring;
regex_t rcomp;
int (*refine_match)(char *name, struct irq_info *info);
int type;
int class;
};
static int check_platform_device(char *name, struct irq_info *info)
{
DIR *dirfd;
char path[512];
struct dirent *ent;
int rc = -ENOENT, i;
static struct pdev_irq_info {
char *d_name;
int type;
int class;
} pdev_irq_info[] = {
{"ata", IRQ_TYPE_LEGACY, IRQ_SCSI},
{"net", IRQ_TYPE_LEGACY, IRQ_ETH},
{"usb", IRQ_TYPE_LEGACY, IRQ_OTHER},
{NULL},
};
memset(path, 0, 512);
strcat(path, "/sys/devices/platform/");
strcat(path, name);
strcat(path, "/");
dirfd = opendir(path);
if (!dirfd) {
log(TO_ALL, LOG_DEBUG, "No directory %s: %s\n", path, strerror(errno));
return -ENOENT;
}
while ((ent = readdir(dirfd)) != NULL) {
log(TO_ALL, LOG_DEBUG, "Checking entry %s\n", ent->d_name);
for (i = 0; pdev_irq_info[i].d_name != NULL; i++) {
if (!strncmp(ent->d_name, pdev_irq_info[i].d_name, strlen(pdev_irq_info[i].d_name))) {
info->type = pdev_irq_info[i].type;
info->class = pdev_irq_info[i].class;
rc = 0;
goto out;
}
}
}
out:
closedir(dirfd);
log(TO_ALL, LOG_DEBUG, "IRQ %s is of type %d and class %d\n", name, info->type, info->class);
return rc;
}
static void guess_arm_irq_hints(char *name, struct irq_info *info)
{
int i, rc;
static int compiled = 0;
/* Note: Last entry is a catchall */
static struct irq_match matches[] = {
{ "eth.*" ,{NULL} ,NULL, IRQ_TYPE_LEGACY, IRQ_GBETH },
{ "[A-Z0-9]{4}[0-9a-f]{4}", {NULL} ,check_platform_device, IRQ_TYPE_LEGACY, IRQ_OTHER},
{ "PNP[0-9a-f]{4}", {NULL} ,check_platform_device, IRQ_TYPE_LEGACY, IRQ_OTHER},
{ ".*", {NULL}, NULL, IRQ_TYPE_LEGACY, IRQ_OTHER},
{NULL},
};
if (!compiled) {
for (i=0; matches[i].matchstring != NULL; i++) {
rc = regcomp(&matches[i].rcomp, matches[i].matchstring, REG_EXTENDED | REG_NOSUB);
if (rc) {
char errbuf[256];
regerror(rc, &matches[i].rcomp, errbuf, 256);
log(TO_ALL, LOG_WARNING, "WARNING: Failed to compile regex %s : %s\n",
matches[i].matchstring, errbuf);
return;
}
}
compiled = 1;
}
for (i=0; matches[i].matchstring != NULL; i++) {
if (!regexec(&matches[i].rcomp, name, 0, NULL, 0)) {
info->type = matches[i].type;
info->class = matches[i].class;
if (matches[i].refine_match)
matches[i].refine_match(name, info);
log(TO_ALL, LOG_DEBUG, "IRQ %s(%d) guessed as class %d\n", name, info->irq,info->class);
}
}
}
#endif
GList* collect_full_irq_list()
{
GList *tmp_list = NULL;
FILE *file;
char *line = NULL;
size_t size = 0;
char *irq_name, *irq_mod, *savedptr, *last_token, *p;
#ifdef AARCH64
char *tmp;
#endif
file = fopen("/proc/interrupts", "r");
if (!file)
return NULL;
/* first line is the header we don't need; nuke it */
if (getline(&line, &size, file)==0) {
free(line);
fclose(file);
return NULL;
}
while (!feof(file)) {
int number;
int is_xen_dyn = 0;
struct irq_info *info;
char *c;
char *savedline = NULL;
if (getline(&line, &size, file)==0)
break;
/* lines with letters in front are special, like NMI count. Ignore */
c = line;
while (isblank(*(c)))
c++;
if (!(*c>='0' && *c<='9'))
break;
c = strchr(line, ':');
if (!c)
continue;
savedline = strdup(line);
irq_name = strtok_r(savedline, " ", &savedptr);
if (strstr(irq_name, "xen-dyn") != NULL)
is_xen_dyn = 1;
last_token = strtok_r(NULL, " ", &savedptr);
while ((p = strtok_r(NULL, " ", &savedptr))) {
irq_name = last_token;
if (strstr(irq_name, "xen-dyn") != NULL)
is_xen_dyn = 1;
last_token = p;
}
#ifdef AARCH64
/* Of course the formatting for /proc/interrupts is different on different arches */
irq_name = last_token;
tmp = strchr(irq_name, '\n');
if (tmp)
*tmp = 0;
#endif
irq_mod = last_token;
*c = 0;
c++;
number = strtoul(line, NULL, 10);
info = calloc(sizeof(struct irq_info), 1);
if (info) {
info->irq = number;
if (strstr(irq_name, "-event") != NULL && is_xen_dyn == 1) {
info->type = IRQ_TYPE_VIRT_EVENT;
info->class = IRQ_VIRT_EVENT;
} else {
#ifdef AARCH64
guess_arm_irq_hints(irq_name, info);
#else
info->type = IRQ_TYPE_LEGACY;
info->class = IRQ_OTHER;
#endif
}
info->name = strdupa(irq_mod);
tmp_list = g_list_append(tmp_list, info);
}
free(savedline);
}
fclose(file);
free(line);
return tmp_list;
}
void parse_proc_interrupts(void)
{
FILE *file;
char *line = NULL;
size_t size = 0;
file = fopen("/proc/interrupts", "r");
if (!file)
return;
/* first line is the header we don't need; nuke it */
if (getline(&line, &size, file)==0) {
free(line);
fclose(file);
return;
}
while (!feof(file)) {
int cpunr;
int number;
uint64_t count;
char *c, *c2;
struct irq_info *info;
char savedline[1024];
if (getline(&line, &size, file)==0)
break;
if (!proc_int_has_msi)
if (strstr(line, "MSI") != NULL)
proc_int_has_msi = 1;
/* lines with letters in front are special, like NMI count. Ignore */
c = line;
while (isblank(*(c)))
c++;
if (!(*c>='0' && *c<='9'))
break;
c = strchr(line, ':');
if (!c)
continue;
strncpy(savedline, line, sizeof(savedline)-1);
*c = 0;
c++;
number = strtoul(line, NULL, 10);
info = get_irq_info(number);
if (!info) {
need_rescan = 1;
break;
}
count = 0;
cpunr = 0;
c2=NULL;
while (1) {
uint64_t C;
C = strtoull(c, &c2, 10);
if (c==c2) /* end of numbers */
break;
count += C;
c=c2;
cpunr++;
}
if (cpunr != core_count) {
need_rescan = 1;
break;
}
/* IRQ removed and reinserted, need restart or this will
* cause an overflow and IRQ won't be rebalanced again
*/
if (count < info->irq_count) {
need_rescan = 1;
break;
}
info->last_irq_count = info->irq_count;
info->irq_count = count;
/* is interrupt MSI based? */
if ((info->type == IRQ_TYPE_MSI) || (info->type == IRQ_TYPE_MSIX))
msi_found_in_sysfs = 1;
}
if ((proc_int_has_msi) && (!msi_found_in_sysfs) && (!need_rescan)) {
log(TO_ALL, LOG_WARNING, "WARNING: MSI interrupts found in /proc/interrupts\n");
log(TO_ALL, LOG_WARNING, "But none found in sysfs, you need to update your kernel\n");
log(TO_ALL, LOG_WARNING, "Until then, IRQs will be improperly classified\n");
/*
* Set msi_foun_in_sysfs, so we don't get this error constantly
*/
msi_found_in_sysfs = 1;
}
fclose(file);
free(line);
}
static void assign_load_slice(struct irq_info *info, void *data)
{
uint64_t *load_slice = data;
info->load = (info->irq_count - info->last_irq_count) * *load_slice;
/*
* Every IRQ has at least a load of 1
*/
if (!info->load)
info->load++;
}
/*
* Recursive helper to estimate the number of irqs shared between
* multiple topology objects that was handled by this particular object
*/
static uint64_t get_parent_branch_irq_count_share(struct topo_obj *d)
{
uint64_t total_irq_count = 0;
if (d->parent) {
total_irq_count = get_parent_branch_irq_count_share(d->parent);
total_irq_count /= g_list_length((d->parent)->children);
}
total_irq_count += d->irq_count;
return total_irq_count;
}
static void get_children_branch_irq_count(struct topo_obj *d, void *data)
{
uint64_t *total_irq_count = data;
if (g_list_length(d->children) > 0)
for_each_object(d->children, get_children_branch_irq_count, total_irq_count);
*total_irq_count += d->irq_count;
}
static void compute_irq_branch_load_share(struct topo_obj *d, void *data __attribute__((unused)))
{
uint64_t local_irq_counts = 0;
uint64_t load_slice;
if (g_list_length(d->interrupts) > 0) {
local_irq_counts = get_parent_branch_irq_count_share(d);
if (g_list_length(d->children) > 0)
for_each_object(d->children, get_children_branch_irq_count, &local_irq_counts);
load_slice = local_irq_counts ? (d->load / local_irq_counts) : 1;
for_each_irq(d->interrupts, assign_load_slice, &load_slice);
}
}
static void accumulate_irq_count(struct irq_info *info, void *data)
{
uint64_t *acc = data;
*acc += (info->irq_count - info->last_irq_count);
}
static void accumulate_interrupts(struct topo_obj *d, void *data __attribute__((unused)))
{
if (g_list_length(d->children) > 0) {
for_each_object(d->children, accumulate_interrupts, NULL);
}
d->irq_count = 0;
if (g_list_length(d->interrupts) > 0)
for_each_irq(d->interrupts, accumulate_irq_count, &(d->irq_count));
}
static void accumulate_load(struct topo_obj *d, void *data)
{
uint64_t *load = data;
*load += d->load;
}
static void set_load(struct topo_obj *d, void *data __attribute__((unused)))
{
if (g_list_length(d->children) > 0) {
for_each_object(d->children, set_load, NULL);
d->load = 0;
for_each_object(d->children, accumulate_load, &(d->load));
}
}
void parse_proc_stat(void)
{
FILE *file;
char *line = NULL;
size_t size = 0;
int cpunr, rc, cpucount;
struct topo_obj *cpu;
unsigned long long irq_load, softirq_load;
file = fopen("/proc/stat", "r");
if (!file) {
log(TO_ALL, LOG_WARNING, "WARNING cant open /proc/stat. balacing is broken\n");
return;
}
/* first line is the header we don't need; nuke it */
if (getline(&line, &size, file)==0) {
free(line);
log(TO_ALL, LOG_WARNING, "WARNING read /proc/stat. balancing is broken\n");
fclose(file);
return;
}
cpucount = 0;
while (!feof(file)) {
if (getline(&line, &size, file)==0)
break;
if (!strstr(line, "cpu"))
break;
cpunr = strtoul(&line[3], NULL, 10);
if (cpu_isset(cpunr, banned_cpus))
continue;
rc = sscanf(line, "%*s %*u %*u %*u %*u %*u %llu %llu", &irq_load, &softirq_load);
if (rc < 2)
break;
cpu = find_cpu_core(cpunr);
if (!cpu)
break;
cpucount++;
/*
* For each cpu add the irq and softirq load and propagate that
* all the way up the device tree
*/
if (cycle_count) {
cpu->load = (irq_load + softirq_load) - (cpu->last_load);
/*
* the [soft]irq_load values are in jiffies, with
* HZ jiffies per second. Convert the load to nanoseconds
* to get a better integer resolution of nanoseconds per
* interrupt.
*/
cpu->load *= NSEC_PER_SEC/HZ;
}
cpu->last_load = (irq_load + softirq_load);
}
fclose(file);
free(line);
if (cpucount != get_cpu_count()) {
log(TO_ALL, LOG_WARNING, "WARNING, didn't collect load info for all cpus, balancing is broken\n");
return;
}
/*
* Set the load values for all objects above cpus
*/
for_each_object(numa_nodes, set_load, NULL);
/*
* Collect local irq_count on each object
*/
for_each_object(numa_nodes, accumulate_interrupts, NULL);
/*
* Now that we have load for each cpu attribute a fair share of the load
* to each irq on that cpu
*/
for_each_object(cpus, compute_irq_branch_load_share, NULL);
for_each_object(cache_domains, compute_irq_branch_load_share, NULL);
for_each_object(packages, compute_irq_branch_load_share, NULL);
for_each_object(numa_nodes, compute_irq_branch_load_share, NULL);
}