Revision 72f961320d5d15bfcb26dbe3edaa3f7d25fd2c8a authored by Paolo Abeni on 10 June 2021, 22:59:40 UTC, committed by David S. Miller on 10 June 2021, 23:47:44 UTC
If the host is under sever memory pressure, and RX forward memory allocation for the msk fails, we try to borrow the required memory from the ingress subflow. The current attempt is a bit flaky: if skb->truesize is less than SK_MEM_QUANTUM, the ssk will not release any memory, and the next schedule will fail again. Instead, directly move the required amount of pages from the ssk to the msk, if available Fixes: 9c3f94e1681b ("mptcp: add missing memory scheduling in the rx path") Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 22488e4
list_lru.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2013 Red Hat, Inc. and Parallels Inc. All rights reserved.
* Authors: David Chinner and Glauber Costa
*
* Generic LRU infrastructure
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/list_lru.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/memcontrol.h>
#include "slab.h"
#ifdef CONFIG_MEMCG_KMEM
static LIST_HEAD(list_lrus);
static DEFINE_MUTEX(list_lrus_mutex);
static void list_lru_register(struct list_lru *lru)
{
mutex_lock(&list_lrus_mutex);
list_add(&lru->list, &list_lrus);
mutex_unlock(&list_lrus_mutex);
}
static void list_lru_unregister(struct list_lru *lru)
{
mutex_lock(&list_lrus_mutex);
list_del(&lru->list);
mutex_unlock(&list_lrus_mutex);
}
static int lru_shrinker_id(struct list_lru *lru)
{
return lru->shrinker_id;
}
static inline bool list_lru_memcg_aware(struct list_lru *lru)
{
return lru->memcg_aware;
}
static inline struct list_lru_one *
list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
{
struct list_lru_memcg *memcg_lrus;
/*
* Either lock or RCU protects the array of per cgroup lists
* from relocation (see memcg_update_list_lru_node).
*/
memcg_lrus = rcu_dereference_check(nlru->memcg_lrus,
lockdep_is_held(&nlru->lock));
if (memcg_lrus && idx >= 0)
return memcg_lrus->lru[idx];
return &nlru->lru;
}
static inline struct list_lru_one *
list_lru_from_kmem(struct list_lru_node *nlru, void *ptr,
struct mem_cgroup **memcg_ptr)
{
struct list_lru_one *l = &nlru->lru;
struct mem_cgroup *memcg = NULL;
if (!nlru->memcg_lrus)
goto out;
memcg = mem_cgroup_from_obj(ptr);
if (!memcg)
goto out;
l = list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
out:
if (memcg_ptr)
*memcg_ptr = memcg;
return l;
}
#else
static void list_lru_register(struct list_lru *lru)
{
}
static void list_lru_unregister(struct list_lru *lru)
{
}
static int lru_shrinker_id(struct list_lru *lru)
{
return -1;
}
static inline bool list_lru_memcg_aware(struct list_lru *lru)
{
return false;
}
static inline struct list_lru_one *
list_lru_from_memcg_idx(struct list_lru_node *nlru, int idx)
{
return &nlru->lru;
}
static inline struct list_lru_one *
list_lru_from_kmem(struct list_lru_node *nlru, void *ptr,
struct mem_cgroup **memcg_ptr)
{
if (memcg_ptr)
*memcg_ptr = NULL;
return &nlru->lru;
}
#endif /* CONFIG_MEMCG_KMEM */
bool list_lru_add(struct list_lru *lru, struct list_head *item)
{
int nid = page_to_nid(virt_to_page(item));
struct list_lru_node *nlru = &lru->node[nid];
struct mem_cgroup *memcg;
struct list_lru_one *l;
spin_lock(&nlru->lock);
if (list_empty(item)) {
l = list_lru_from_kmem(nlru, item, &memcg);
list_add_tail(item, &l->list);
/* Set shrinker bit if the first element was added */
if (!l->nr_items++)
set_shrinker_bit(memcg, nid,
lru_shrinker_id(lru));
nlru->nr_items++;
spin_unlock(&nlru->lock);
return true;
}
spin_unlock(&nlru->lock);
return false;
}
EXPORT_SYMBOL_GPL(list_lru_add);
bool list_lru_del(struct list_lru *lru, struct list_head *item)
{
int nid = page_to_nid(virt_to_page(item));
struct list_lru_node *nlru = &lru->node[nid];
struct list_lru_one *l;
spin_lock(&nlru->lock);
if (!list_empty(item)) {
l = list_lru_from_kmem(nlru, item, NULL);
list_del_init(item);
l->nr_items--;
nlru->nr_items--;
spin_unlock(&nlru->lock);
return true;
}
spin_unlock(&nlru->lock);
return false;
}
EXPORT_SYMBOL_GPL(list_lru_del);
void list_lru_isolate(struct list_lru_one *list, struct list_head *item)
{
list_del_init(item);
list->nr_items--;
}
EXPORT_SYMBOL_GPL(list_lru_isolate);
void list_lru_isolate_move(struct list_lru_one *list, struct list_head *item,
struct list_head *head)
{
list_move(item, head);
list->nr_items--;
}
EXPORT_SYMBOL_GPL(list_lru_isolate_move);
unsigned long list_lru_count_one(struct list_lru *lru,
int nid, struct mem_cgroup *memcg)
{
struct list_lru_node *nlru = &lru->node[nid];
struct list_lru_one *l;
unsigned long count;
rcu_read_lock();
l = list_lru_from_memcg_idx(nlru, memcg_cache_id(memcg));
count = READ_ONCE(l->nr_items);
rcu_read_unlock();
return count;
}
EXPORT_SYMBOL_GPL(list_lru_count_one);
unsigned long list_lru_count_node(struct list_lru *lru, int nid)
{
struct list_lru_node *nlru;
nlru = &lru->node[nid];
return nlru->nr_items;
}
EXPORT_SYMBOL_GPL(list_lru_count_node);
static unsigned long
__list_lru_walk_one(struct list_lru_node *nlru, int memcg_idx,
list_lru_walk_cb isolate, void *cb_arg,
unsigned long *nr_to_walk)
{
struct list_lru_one *l;
struct list_head *item, *n;
unsigned long isolated = 0;
l = list_lru_from_memcg_idx(nlru, memcg_idx);
restart:
list_for_each_safe(item, n, &l->list) {
enum lru_status ret;
/*
* decrement nr_to_walk first so that we don't livelock if we
* get stuck on large numbers of LRU_RETRY items
*/
if (!*nr_to_walk)
break;
--*nr_to_walk;
ret = isolate(item, l, &nlru->lock, cb_arg);
switch (ret) {
case LRU_REMOVED_RETRY:
assert_spin_locked(&nlru->lock);
fallthrough;
case LRU_REMOVED:
isolated++;
nlru->nr_items--;
/*
* If the lru lock has been dropped, our list
* traversal is now invalid and so we have to
* restart from scratch.
*/
if (ret == LRU_REMOVED_RETRY)
goto restart;
break;
case LRU_ROTATE:
list_move_tail(item, &l->list);
break;
case LRU_SKIP:
break;
case LRU_RETRY:
/*
* The lru lock has been dropped, our list traversal is
* now invalid and so we have to restart from scratch.
*/
assert_spin_locked(&nlru->lock);
goto restart;
default:
BUG();
}
}
return isolated;
}
unsigned long
list_lru_walk_one(struct list_lru *lru, int nid, struct mem_cgroup *memcg,
list_lru_walk_cb isolate, void *cb_arg,
unsigned long *nr_to_walk)
{
struct list_lru_node *nlru = &lru->node[nid];
unsigned long ret;
spin_lock(&nlru->lock);
ret = __list_lru_walk_one(nlru, memcg_cache_id(memcg), isolate, cb_arg,
nr_to_walk);
spin_unlock(&nlru->lock);
return ret;
}
EXPORT_SYMBOL_GPL(list_lru_walk_one);
unsigned long
list_lru_walk_one_irq(struct list_lru *lru, int nid, struct mem_cgroup *memcg,
list_lru_walk_cb isolate, void *cb_arg,
unsigned long *nr_to_walk)
{
struct list_lru_node *nlru = &lru->node[nid];
unsigned long ret;
spin_lock_irq(&nlru->lock);
ret = __list_lru_walk_one(nlru, memcg_cache_id(memcg), isolate, cb_arg,
nr_to_walk);
spin_unlock_irq(&nlru->lock);
return ret;
}
unsigned long list_lru_walk_node(struct list_lru *lru, int nid,
list_lru_walk_cb isolate, void *cb_arg,
unsigned long *nr_to_walk)
{
long isolated = 0;
int memcg_idx;
isolated += list_lru_walk_one(lru, nid, NULL, isolate, cb_arg,
nr_to_walk);
if (*nr_to_walk > 0 && list_lru_memcg_aware(lru)) {
for_each_memcg_cache_index(memcg_idx) {
struct list_lru_node *nlru = &lru->node[nid];
spin_lock(&nlru->lock);
isolated += __list_lru_walk_one(nlru, memcg_idx,
isolate, cb_arg,
nr_to_walk);
spin_unlock(&nlru->lock);
if (*nr_to_walk <= 0)
break;
}
}
return isolated;
}
EXPORT_SYMBOL_GPL(list_lru_walk_node);
static void init_one_lru(struct list_lru_one *l)
{
INIT_LIST_HEAD(&l->list);
l->nr_items = 0;
}
#ifdef CONFIG_MEMCG_KMEM
static void __memcg_destroy_list_lru_node(struct list_lru_memcg *memcg_lrus,
int begin, int end)
{
int i;
for (i = begin; i < end; i++)
kfree(memcg_lrus->lru[i]);
}
static int __memcg_init_list_lru_node(struct list_lru_memcg *memcg_lrus,
int begin, int end)
{
int i;
for (i = begin; i < end; i++) {
struct list_lru_one *l;
l = kmalloc(sizeof(struct list_lru_one), GFP_KERNEL);
if (!l)
goto fail;
init_one_lru(l);
memcg_lrus->lru[i] = l;
}
return 0;
fail:
__memcg_destroy_list_lru_node(memcg_lrus, begin, i);
return -ENOMEM;
}
static int memcg_init_list_lru_node(struct list_lru_node *nlru)
{
struct list_lru_memcg *memcg_lrus;
int size = memcg_nr_cache_ids;
memcg_lrus = kvmalloc(sizeof(*memcg_lrus) +
size * sizeof(void *), GFP_KERNEL);
if (!memcg_lrus)
return -ENOMEM;
if (__memcg_init_list_lru_node(memcg_lrus, 0, size)) {
kvfree(memcg_lrus);
return -ENOMEM;
}
RCU_INIT_POINTER(nlru->memcg_lrus, memcg_lrus);
return 0;
}
static void memcg_destroy_list_lru_node(struct list_lru_node *nlru)
{
struct list_lru_memcg *memcg_lrus;
/*
* This is called when shrinker has already been unregistered,
* and nobody can use it. So, there is no need to use kvfree_rcu().
*/
memcg_lrus = rcu_dereference_protected(nlru->memcg_lrus, true);
__memcg_destroy_list_lru_node(memcg_lrus, 0, memcg_nr_cache_ids);
kvfree(memcg_lrus);
}
static int memcg_update_list_lru_node(struct list_lru_node *nlru,
int old_size, int new_size)
{
struct list_lru_memcg *old, *new;
BUG_ON(old_size > new_size);
old = rcu_dereference_protected(nlru->memcg_lrus,
lockdep_is_held(&list_lrus_mutex));
new = kvmalloc(sizeof(*new) + new_size * sizeof(void *), GFP_KERNEL);
if (!new)
return -ENOMEM;
if (__memcg_init_list_lru_node(new, old_size, new_size)) {
kvfree(new);
return -ENOMEM;
}
memcpy(&new->lru, &old->lru, old_size * sizeof(void *));
/*
* The locking below allows readers that hold nlru->lock avoid taking
* rcu_read_lock (see list_lru_from_memcg_idx).
*
* Since list_lru_{add,del} may be called under an IRQ-safe lock,
* we have to use IRQ-safe primitives here to avoid deadlock.
*/
spin_lock_irq(&nlru->lock);
rcu_assign_pointer(nlru->memcg_lrus, new);
spin_unlock_irq(&nlru->lock);
kvfree_rcu(old, rcu);
return 0;
}
static void memcg_cancel_update_list_lru_node(struct list_lru_node *nlru,
int old_size, int new_size)
{
struct list_lru_memcg *memcg_lrus;
memcg_lrus = rcu_dereference_protected(nlru->memcg_lrus,
lockdep_is_held(&list_lrus_mutex));
/* do not bother shrinking the array back to the old size, because we
* cannot handle allocation failures here */
__memcg_destroy_list_lru_node(memcg_lrus, old_size, new_size);
}
static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
{
int i;
lru->memcg_aware = memcg_aware;
if (!memcg_aware)
return 0;
for_each_node(i) {
if (memcg_init_list_lru_node(&lru->node[i]))
goto fail;
}
return 0;
fail:
for (i = i - 1; i >= 0; i--) {
if (!lru->node[i].memcg_lrus)
continue;
memcg_destroy_list_lru_node(&lru->node[i]);
}
return -ENOMEM;
}
static void memcg_destroy_list_lru(struct list_lru *lru)
{
int i;
if (!list_lru_memcg_aware(lru))
return;
for_each_node(i)
memcg_destroy_list_lru_node(&lru->node[i]);
}
static int memcg_update_list_lru(struct list_lru *lru,
int old_size, int new_size)
{
int i;
if (!list_lru_memcg_aware(lru))
return 0;
for_each_node(i) {
if (memcg_update_list_lru_node(&lru->node[i],
old_size, new_size))
goto fail;
}
return 0;
fail:
for (i = i - 1; i >= 0; i--) {
if (!lru->node[i].memcg_lrus)
continue;
memcg_cancel_update_list_lru_node(&lru->node[i],
old_size, new_size);
}
return -ENOMEM;
}
static void memcg_cancel_update_list_lru(struct list_lru *lru,
int old_size, int new_size)
{
int i;
if (!list_lru_memcg_aware(lru))
return;
for_each_node(i)
memcg_cancel_update_list_lru_node(&lru->node[i],
old_size, new_size);
}
int memcg_update_all_list_lrus(int new_size)
{
int ret = 0;
struct list_lru *lru;
int old_size = memcg_nr_cache_ids;
mutex_lock(&list_lrus_mutex);
list_for_each_entry(lru, &list_lrus, list) {
ret = memcg_update_list_lru(lru, old_size, new_size);
if (ret)
goto fail;
}
out:
mutex_unlock(&list_lrus_mutex);
return ret;
fail:
list_for_each_entry_continue_reverse(lru, &list_lrus, list)
memcg_cancel_update_list_lru(lru, old_size, new_size);
goto out;
}
static void memcg_drain_list_lru_node(struct list_lru *lru, int nid,
int src_idx, struct mem_cgroup *dst_memcg)
{
struct list_lru_node *nlru = &lru->node[nid];
int dst_idx = dst_memcg->kmemcg_id;
struct list_lru_one *src, *dst;
/*
* Since list_lru_{add,del} may be called under an IRQ-safe lock,
* we have to use IRQ-safe primitives here to avoid deadlock.
*/
spin_lock_irq(&nlru->lock);
src = list_lru_from_memcg_idx(nlru, src_idx);
dst = list_lru_from_memcg_idx(nlru, dst_idx);
list_splice_init(&src->list, &dst->list);
if (src->nr_items) {
dst->nr_items += src->nr_items;
set_shrinker_bit(dst_memcg, nid, lru_shrinker_id(lru));
src->nr_items = 0;
}
spin_unlock_irq(&nlru->lock);
}
static void memcg_drain_list_lru(struct list_lru *lru,
int src_idx, struct mem_cgroup *dst_memcg)
{
int i;
if (!list_lru_memcg_aware(lru))
return;
for_each_node(i)
memcg_drain_list_lru_node(lru, i, src_idx, dst_memcg);
}
void memcg_drain_all_list_lrus(int src_idx, struct mem_cgroup *dst_memcg)
{
struct list_lru *lru;
mutex_lock(&list_lrus_mutex);
list_for_each_entry(lru, &list_lrus, list)
memcg_drain_list_lru(lru, src_idx, dst_memcg);
mutex_unlock(&list_lrus_mutex);
}
#else
static int memcg_init_list_lru(struct list_lru *lru, bool memcg_aware)
{
return 0;
}
static void memcg_destroy_list_lru(struct list_lru *lru)
{
}
#endif /* CONFIG_MEMCG_KMEM */
int __list_lru_init(struct list_lru *lru, bool memcg_aware,
struct lock_class_key *key, struct shrinker *shrinker)
{
int i;
int err = -ENOMEM;
#ifdef CONFIG_MEMCG_KMEM
if (shrinker)
lru->shrinker_id = shrinker->id;
else
lru->shrinker_id = -1;
#endif
memcg_get_cache_ids();
lru->node = kcalloc(nr_node_ids, sizeof(*lru->node), GFP_KERNEL);
if (!lru->node)
goto out;
for_each_node(i) {
spin_lock_init(&lru->node[i].lock);
if (key)
lockdep_set_class(&lru->node[i].lock, key);
init_one_lru(&lru->node[i].lru);
}
err = memcg_init_list_lru(lru, memcg_aware);
if (err) {
kfree(lru->node);
/* Do this so a list_lru_destroy() doesn't crash: */
lru->node = NULL;
goto out;
}
list_lru_register(lru);
out:
memcg_put_cache_ids();
return err;
}
EXPORT_SYMBOL_GPL(__list_lru_init);
void list_lru_destroy(struct list_lru *lru)
{
/* Already destroyed or not yet initialized? */
if (!lru->node)
return;
memcg_get_cache_ids();
list_lru_unregister(lru);
memcg_destroy_list_lru(lru);
kfree(lru->node);
lru->node = NULL;
#ifdef CONFIG_MEMCG_KMEM
lru->shrinker_id = -1;
#endif
memcg_put_cache_ids();
}
EXPORT_SYMBOL_GPL(list_lru_destroy);
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