mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-29 23:53:32 +00:00
298fb37298
Additional prefix helps clarify that these source files implement path selectors. Required updating Makefile to still build modules _without_ the "dm-ps" prefix to preserve dm-multipath's ability to autoload path selector modules. While at it, cleaned up some DM whitespace in Makefile. Signed-off-by: Mike Snitzer <snitzer@redhat.com>
272 lines
5.2 KiB
C
272 lines
5.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
|
|
/*
|
|
* Copyright (C) 2020 Oracle Corporation
|
|
*
|
|
* Module Author: Mike Christie
|
|
*/
|
|
#include "dm-path-selector.h"
|
|
|
|
#include <linux/device-mapper.h>
|
|
#include <linux/module.h>
|
|
|
|
#define DM_MSG_PREFIX "multipath io-affinity"
|
|
|
|
struct path_info {
|
|
struct dm_path *path;
|
|
cpumask_var_t cpumask;
|
|
refcount_t refcount;
|
|
bool failed;
|
|
};
|
|
|
|
struct selector {
|
|
struct path_info **path_map;
|
|
cpumask_var_t path_mask;
|
|
atomic_t map_misses;
|
|
};
|
|
|
|
static void ioa_free_path(struct selector *s, unsigned int cpu)
|
|
{
|
|
struct path_info *pi = s->path_map[cpu];
|
|
|
|
if (!pi)
|
|
return;
|
|
|
|
if (refcount_dec_and_test(&pi->refcount)) {
|
|
cpumask_clear_cpu(cpu, s->path_mask);
|
|
free_cpumask_var(pi->cpumask);
|
|
kfree(pi);
|
|
|
|
s->path_map[cpu] = NULL;
|
|
}
|
|
}
|
|
|
|
static int ioa_add_path(struct path_selector *ps, struct dm_path *path,
|
|
int argc, char **argv, char **error)
|
|
{
|
|
struct selector *s = ps->context;
|
|
struct path_info *pi = NULL;
|
|
unsigned int cpu;
|
|
int ret;
|
|
|
|
if (argc != 1) {
|
|
*error = "io-affinity ps: invalid number of arguments";
|
|
return -EINVAL;
|
|
}
|
|
|
|
pi = kzalloc(sizeof(*pi), GFP_KERNEL);
|
|
if (!pi) {
|
|
*error = "io-affinity ps: Error allocating path context";
|
|
return -ENOMEM;
|
|
}
|
|
|
|
pi->path = path;
|
|
path->pscontext = pi;
|
|
refcount_set(&pi->refcount, 1);
|
|
|
|
if (!zalloc_cpumask_var(&pi->cpumask, GFP_KERNEL)) {
|
|
*error = "io-affinity ps: Error allocating cpumask context";
|
|
ret = -ENOMEM;
|
|
goto free_pi;
|
|
}
|
|
|
|
ret = cpumask_parse(argv[0], pi->cpumask);
|
|
if (ret) {
|
|
*error = "io-affinity ps: invalid cpumask";
|
|
ret = -EINVAL;
|
|
goto free_mask;
|
|
}
|
|
|
|
for_each_cpu(cpu, pi->cpumask) {
|
|
if (cpu >= nr_cpu_ids) {
|
|
DMWARN_LIMIT("Ignoring mapping for CPU %u. Max CPU is %u",
|
|
cpu, nr_cpu_ids);
|
|
break;
|
|
}
|
|
|
|
if (s->path_map[cpu]) {
|
|
DMWARN("CPU mapping for %u exists. Ignoring.", cpu);
|
|
continue;
|
|
}
|
|
|
|
cpumask_set_cpu(cpu, s->path_mask);
|
|
s->path_map[cpu] = pi;
|
|
refcount_inc(&pi->refcount);
|
|
continue;
|
|
}
|
|
|
|
if (refcount_dec_and_test(&pi->refcount)) {
|
|
*error = "io-affinity ps: No new/valid CPU mapping found";
|
|
ret = -EINVAL;
|
|
goto free_mask;
|
|
}
|
|
|
|
return 0;
|
|
|
|
free_mask:
|
|
free_cpumask_var(pi->cpumask);
|
|
free_pi:
|
|
kfree(pi);
|
|
return ret;
|
|
}
|
|
|
|
static int ioa_create(struct path_selector *ps, unsigned argc, char **argv)
|
|
{
|
|
struct selector *s;
|
|
|
|
s = kmalloc(sizeof(*s), GFP_KERNEL);
|
|
if (!s)
|
|
return -ENOMEM;
|
|
|
|
s->path_map = kzalloc(nr_cpu_ids * sizeof(struct path_info *),
|
|
GFP_KERNEL);
|
|
if (!s->path_map)
|
|
goto free_selector;
|
|
|
|
if (!zalloc_cpumask_var(&s->path_mask, GFP_KERNEL))
|
|
goto free_map;
|
|
|
|
atomic_set(&s->map_misses, 0);
|
|
ps->context = s;
|
|
return 0;
|
|
|
|
free_map:
|
|
kfree(s->path_map);
|
|
free_selector:
|
|
kfree(s);
|
|
return -ENOMEM;
|
|
}
|
|
|
|
static void ioa_destroy(struct path_selector *ps)
|
|
{
|
|
struct selector *s = ps->context;
|
|
unsigned cpu;
|
|
|
|
for_each_cpu(cpu, s->path_mask)
|
|
ioa_free_path(s, cpu);
|
|
|
|
free_cpumask_var(s->path_mask);
|
|
kfree(s->path_map);
|
|
kfree(s);
|
|
|
|
ps->context = NULL;
|
|
}
|
|
|
|
static int ioa_status(struct path_selector *ps, struct dm_path *path,
|
|
status_type_t type, char *result, unsigned int maxlen)
|
|
{
|
|
struct selector *s = ps->context;
|
|
struct path_info *pi;
|
|
int sz = 0;
|
|
|
|
if (!path) {
|
|
DMEMIT("0 ");
|
|
return sz;
|
|
}
|
|
|
|
switch(type) {
|
|
case STATUSTYPE_INFO:
|
|
DMEMIT("%d ", atomic_read(&s->map_misses));
|
|
break;
|
|
case STATUSTYPE_TABLE:
|
|
pi = path->pscontext;
|
|
DMEMIT("%*pb ", cpumask_pr_args(pi->cpumask));
|
|
break;
|
|
}
|
|
|
|
return sz;
|
|
}
|
|
|
|
static void ioa_fail_path(struct path_selector *ps, struct dm_path *p)
|
|
{
|
|
struct path_info *pi = p->pscontext;
|
|
|
|
pi->failed = true;
|
|
}
|
|
|
|
static int ioa_reinstate_path(struct path_selector *ps, struct dm_path *p)
|
|
{
|
|
struct path_info *pi = p->pscontext;
|
|
|
|
pi->failed = false;
|
|
return 0;
|
|
}
|
|
|
|
static struct dm_path *ioa_select_path(struct path_selector *ps,
|
|
size_t nr_bytes)
|
|
{
|
|
unsigned int cpu, node;
|
|
struct selector *s = ps->context;
|
|
const struct cpumask *cpumask;
|
|
struct path_info *pi;
|
|
int i;
|
|
|
|
cpu = get_cpu();
|
|
|
|
pi = s->path_map[cpu];
|
|
if (pi && !pi->failed)
|
|
goto done;
|
|
|
|
/*
|
|
* Perf is not optimal, but we at least try the local node then just
|
|
* try not to fail.
|
|
*/
|
|
if (!pi)
|
|
atomic_inc(&s->map_misses);
|
|
|
|
node = cpu_to_node(cpu);
|
|
cpumask = cpumask_of_node(node);
|
|
for_each_cpu(i, cpumask) {
|
|
pi = s->path_map[i];
|
|
if (pi && !pi->failed)
|
|
goto done;
|
|
}
|
|
|
|
for_each_cpu(i, s->path_mask) {
|
|
pi = s->path_map[i];
|
|
if (pi && !pi->failed)
|
|
goto done;
|
|
}
|
|
pi = NULL;
|
|
|
|
done:
|
|
put_cpu();
|
|
return pi ? pi->path : NULL;
|
|
}
|
|
|
|
static struct path_selector_type ioa_ps = {
|
|
.name = "io-affinity",
|
|
.module = THIS_MODULE,
|
|
.table_args = 1,
|
|
.info_args = 1,
|
|
.create = ioa_create,
|
|
.destroy = ioa_destroy,
|
|
.status = ioa_status,
|
|
.add_path = ioa_add_path,
|
|
.fail_path = ioa_fail_path,
|
|
.reinstate_path = ioa_reinstate_path,
|
|
.select_path = ioa_select_path,
|
|
};
|
|
|
|
static int __init dm_ioa_init(void)
|
|
{
|
|
int ret = dm_register_path_selector(&ioa_ps);
|
|
|
|
if (ret < 0)
|
|
DMERR("register failed %d", ret);
|
|
return ret;
|
|
}
|
|
|
|
static void __exit dm_ioa_exit(void)
|
|
{
|
|
int ret = dm_unregister_path_selector(&ioa_ps);
|
|
|
|
if (ret < 0)
|
|
DMERR("unregister failed %d", ret);
|
|
}
|
|
|
|
module_init(dm_ioa_init);
|
|
module_exit(dm_ioa_exit);
|
|
|
|
MODULE_DESCRIPTION(DM_NAME " multipath path selector that selects paths based on the CPU IO is being executed on");
|
|
MODULE_AUTHOR("Mike Christie <michael.christie@oracle.com>");
|
|
MODULE_LICENSE("GPL");
|