Revision 92a8109e4d3a34fb6b115c9098b51767dc933444 authored by Ross Lagerwall on 08 January 2019, 18:30:56 UTC, committed by Steve French on 11 January 2019, 13:14:40 UTC
The code tries to allocate a contiguous buffer with a size supplied by the server (maxBuf). This could fail if memory is fragmented since it results in high order allocations for commonly used server implementations. It is also wasteful since there are probably few locks in the usual case. Limit the buffer to be no larger than a page to avoid memory allocation failures due to fragmentation. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Signed-off-by: Steve French <stfrench@microsoft.com>
1 parent 15bc77f
ib_rdma.c
/*
* Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* General Public License (GPL) Version 2, available from the file
* COPYING in the main directory of this source tree, or the
* OpenIB.org BSD license below:
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/rculist.h>
#include <linux/llist.h>
#include "rds_single_path.h"
#include "ib_mr.h"
struct workqueue_struct *rds_ib_mr_wq;
static DEFINE_PER_CPU(unsigned long, clean_list_grace);
#define CLEAN_LIST_BUSY_BIT 0
static struct rds_ib_device *rds_ib_get_device(__be32 ipaddr)
{
struct rds_ib_device *rds_ibdev;
struct rds_ib_ipaddr *i_ipaddr;
rcu_read_lock();
list_for_each_entry_rcu(rds_ibdev, &rds_ib_devices, list) {
list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
if (i_ipaddr->ipaddr == ipaddr) {
refcount_inc(&rds_ibdev->refcount);
rcu_read_unlock();
return rds_ibdev;
}
}
}
rcu_read_unlock();
return NULL;
}
static int rds_ib_add_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
{
struct rds_ib_ipaddr *i_ipaddr;
i_ipaddr = kmalloc(sizeof *i_ipaddr, GFP_KERNEL);
if (!i_ipaddr)
return -ENOMEM;
i_ipaddr->ipaddr = ipaddr;
spin_lock_irq(&rds_ibdev->spinlock);
list_add_tail_rcu(&i_ipaddr->list, &rds_ibdev->ipaddr_list);
spin_unlock_irq(&rds_ibdev->spinlock);
return 0;
}
static void rds_ib_remove_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
{
struct rds_ib_ipaddr *i_ipaddr;
struct rds_ib_ipaddr *to_free = NULL;
spin_lock_irq(&rds_ibdev->spinlock);
list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
if (i_ipaddr->ipaddr == ipaddr) {
list_del_rcu(&i_ipaddr->list);
to_free = i_ipaddr;
break;
}
}
spin_unlock_irq(&rds_ibdev->spinlock);
if (to_free)
kfree_rcu(to_free, rcu);
}
int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev,
struct in6_addr *ipaddr)
{
struct rds_ib_device *rds_ibdev_old;
rds_ibdev_old = rds_ib_get_device(ipaddr->s6_addr32[3]);
if (!rds_ibdev_old)
return rds_ib_add_ipaddr(rds_ibdev, ipaddr->s6_addr32[3]);
if (rds_ibdev_old != rds_ibdev) {
rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr->s6_addr32[3]);
rds_ib_dev_put(rds_ibdev_old);
return rds_ib_add_ipaddr(rds_ibdev, ipaddr->s6_addr32[3]);
}
rds_ib_dev_put(rds_ibdev_old);
return 0;
}
void rds_ib_add_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
{
struct rds_ib_connection *ic = conn->c_transport_data;
/* conn was previously on the nodev_conns_list */
spin_lock_irq(&ib_nodev_conns_lock);
BUG_ON(list_empty(&ib_nodev_conns));
BUG_ON(list_empty(&ic->ib_node));
list_del(&ic->ib_node);
spin_lock(&rds_ibdev->spinlock);
list_add_tail(&ic->ib_node, &rds_ibdev->conn_list);
spin_unlock(&rds_ibdev->spinlock);
spin_unlock_irq(&ib_nodev_conns_lock);
ic->rds_ibdev = rds_ibdev;
refcount_inc(&rds_ibdev->refcount);
}
void rds_ib_remove_conn(struct rds_ib_device *rds_ibdev, struct rds_connection *conn)
{
struct rds_ib_connection *ic = conn->c_transport_data;
/* place conn on nodev_conns_list */
spin_lock(&ib_nodev_conns_lock);
spin_lock_irq(&rds_ibdev->spinlock);
BUG_ON(list_empty(&ic->ib_node));
list_del(&ic->ib_node);
spin_unlock_irq(&rds_ibdev->spinlock);
list_add_tail(&ic->ib_node, &ib_nodev_conns);
spin_unlock(&ib_nodev_conns_lock);
ic->rds_ibdev = NULL;
rds_ib_dev_put(rds_ibdev);
}
void rds_ib_destroy_nodev_conns(void)
{
struct rds_ib_connection *ic, *_ic;
LIST_HEAD(tmp_list);
/* avoid calling conn_destroy with irqs off */
spin_lock_irq(&ib_nodev_conns_lock);
list_splice(&ib_nodev_conns, &tmp_list);
spin_unlock_irq(&ib_nodev_conns_lock);
list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node)
rds_conn_destroy(ic->conn);
}
void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_connection *iinfo)
{
struct rds_ib_mr_pool *pool_1m = rds_ibdev->mr_1m_pool;
iinfo->rdma_mr_max = pool_1m->max_items;
iinfo->rdma_mr_size = pool_1m->fmr_attr.max_pages;
}
#if IS_ENABLED(CONFIG_IPV6)
void rds6_ib_get_mr_info(struct rds_ib_device *rds_ibdev,
struct rds6_info_rdma_connection *iinfo6)
{
struct rds_ib_mr_pool *pool_1m = rds_ibdev->mr_1m_pool;
iinfo6->rdma_mr_max = pool_1m->max_items;
iinfo6->rdma_mr_size = pool_1m->fmr_attr.max_pages;
}
#endif
struct rds_ib_mr *rds_ib_reuse_mr(struct rds_ib_mr_pool *pool)
{
struct rds_ib_mr *ibmr = NULL;
struct llist_node *ret;
unsigned long *flag;
preempt_disable();
flag = this_cpu_ptr(&clean_list_grace);
set_bit(CLEAN_LIST_BUSY_BIT, flag);
ret = llist_del_first(&pool->clean_list);
if (ret) {
ibmr = llist_entry(ret, struct rds_ib_mr, llnode);
if (pool->pool_type == RDS_IB_MR_8K_POOL)
rds_ib_stats_inc(s_ib_rdma_mr_8k_reused);
else
rds_ib_stats_inc(s_ib_rdma_mr_1m_reused);
}
clear_bit(CLEAN_LIST_BUSY_BIT, flag);
preempt_enable();
return ibmr;
}
static inline void wait_clean_list_grace(void)
{
int cpu;
unsigned long *flag;
for_each_online_cpu(cpu) {
flag = &per_cpu(clean_list_grace, cpu);
while (test_bit(CLEAN_LIST_BUSY_BIT, flag))
cpu_relax();
}
}
void rds_ib_sync_mr(void *trans_private, int direction)
{
struct rds_ib_mr *ibmr = trans_private;
struct rds_ib_device *rds_ibdev = ibmr->device;
switch (direction) {
case DMA_FROM_DEVICE:
ib_dma_sync_sg_for_cpu(rds_ibdev->dev, ibmr->sg,
ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
break;
case DMA_TO_DEVICE:
ib_dma_sync_sg_for_device(rds_ibdev->dev, ibmr->sg,
ibmr->sg_dma_len, DMA_BIDIRECTIONAL);
break;
}
}
void __rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
{
struct rds_ib_device *rds_ibdev = ibmr->device;
if (ibmr->sg_dma_len) {
ib_dma_unmap_sg(rds_ibdev->dev,
ibmr->sg, ibmr->sg_len,
DMA_BIDIRECTIONAL);
ibmr->sg_dma_len = 0;
}
/* Release the s/g list */
if (ibmr->sg_len) {
unsigned int i;
for (i = 0; i < ibmr->sg_len; ++i) {
struct page *page = sg_page(&ibmr->sg[i]);
/* FIXME we need a way to tell a r/w MR
* from a r/o MR */
WARN_ON(!page->mapping && irqs_disabled());
set_page_dirty(page);
put_page(page);
}
kfree(ibmr->sg);
ibmr->sg = NULL;
ibmr->sg_len = 0;
}
}
void rds_ib_teardown_mr(struct rds_ib_mr *ibmr)
{
unsigned int pinned = ibmr->sg_len;
__rds_ib_teardown_mr(ibmr);
if (pinned) {
struct rds_ib_mr_pool *pool = ibmr->pool;
atomic_sub(pinned, &pool->free_pinned);
}
}
static inline unsigned int rds_ib_flush_goal(struct rds_ib_mr_pool *pool, int free_all)
{
unsigned int item_count;
item_count = atomic_read(&pool->item_count);
if (free_all)
return item_count;
return 0;
}
/*
* given an llist of mrs, put them all into the list_head for more processing
*/
static unsigned int llist_append_to_list(struct llist_head *llist,
struct list_head *list)
{
struct rds_ib_mr *ibmr;
struct llist_node *node;
struct llist_node *next;
unsigned int count = 0;
node = llist_del_all(llist);
while (node) {
next = node->next;
ibmr = llist_entry(node, struct rds_ib_mr, llnode);
list_add_tail(&ibmr->unmap_list, list);
node = next;
count++;
}
return count;
}
/*
* this takes a list head of mrs and turns it into linked llist nodes
* of clusters. Each cluster has linked llist nodes of
* MR_CLUSTER_SIZE mrs that are ready for reuse.
*/
static void list_to_llist_nodes(struct rds_ib_mr_pool *pool,
struct list_head *list,
struct llist_node **nodes_head,
struct llist_node **nodes_tail)
{
struct rds_ib_mr *ibmr;
struct llist_node *cur = NULL;
struct llist_node **next = nodes_head;
list_for_each_entry(ibmr, list, unmap_list) {
cur = &ibmr->llnode;
*next = cur;
next = &cur->next;
}
*next = NULL;
*nodes_tail = cur;
}
/*
* Flush our pool of MRs.
* At a minimum, all currently unused MRs are unmapped.
* If the number of MRs allocated exceeds the limit, we also try
* to free as many MRs as needed to get back to this limit.
*/
int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool,
int free_all, struct rds_ib_mr **ibmr_ret)
{
struct rds_ib_mr *ibmr;
struct llist_node *clean_nodes;
struct llist_node *clean_tail;
LIST_HEAD(unmap_list);
unsigned long unpinned = 0;
unsigned int nfreed = 0, dirty_to_clean = 0, free_goal;
if (pool->pool_type == RDS_IB_MR_8K_POOL)
rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_flush);
else
rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_flush);
if (ibmr_ret) {
DEFINE_WAIT(wait);
while (!mutex_trylock(&pool->flush_lock)) {
ibmr = rds_ib_reuse_mr(pool);
if (ibmr) {
*ibmr_ret = ibmr;
finish_wait(&pool->flush_wait, &wait);
goto out_nolock;
}
prepare_to_wait(&pool->flush_wait, &wait,
TASK_UNINTERRUPTIBLE);
if (llist_empty(&pool->clean_list))
schedule();
ibmr = rds_ib_reuse_mr(pool);
if (ibmr) {
*ibmr_ret = ibmr;
finish_wait(&pool->flush_wait, &wait);
goto out_nolock;
}
}
finish_wait(&pool->flush_wait, &wait);
} else
mutex_lock(&pool->flush_lock);
if (ibmr_ret) {
ibmr = rds_ib_reuse_mr(pool);
if (ibmr) {
*ibmr_ret = ibmr;
goto out;
}
}
/* Get the list of all MRs to be dropped. Ordering matters -
* we want to put drop_list ahead of free_list.
*/
dirty_to_clean = llist_append_to_list(&pool->drop_list, &unmap_list);
dirty_to_clean += llist_append_to_list(&pool->free_list, &unmap_list);
if (free_all)
llist_append_to_list(&pool->clean_list, &unmap_list);
free_goal = rds_ib_flush_goal(pool, free_all);
if (list_empty(&unmap_list))
goto out;
if (pool->use_fastreg)
rds_ib_unreg_frmr(&unmap_list, &nfreed, &unpinned, free_goal);
else
rds_ib_unreg_fmr(&unmap_list, &nfreed, &unpinned, free_goal);
if (!list_empty(&unmap_list)) {
/* we have to make sure that none of the things we're about
* to put on the clean list would race with other cpus trying
* to pull items off. The llist would explode if we managed to
* remove something from the clean list and then add it back again
* while another CPU was spinning on that same item in llist_del_first.
*
* This is pretty unlikely, but just in case wait for an llist grace period
* here before adding anything back into the clean list.
*/
wait_clean_list_grace();
list_to_llist_nodes(pool, &unmap_list, &clean_nodes, &clean_tail);
if (ibmr_ret)
*ibmr_ret = llist_entry(clean_nodes, struct rds_ib_mr, llnode);
/* more than one entry in llist nodes */
if (clean_nodes->next)
llist_add_batch(clean_nodes->next, clean_tail, &pool->clean_list);
}
atomic_sub(unpinned, &pool->free_pinned);
atomic_sub(dirty_to_clean, &pool->dirty_count);
atomic_sub(nfreed, &pool->item_count);
out:
mutex_unlock(&pool->flush_lock);
if (waitqueue_active(&pool->flush_wait))
wake_up(&pool->flush_wait);
out_nolock:
return 0;
}
struct rds_ib_mr *rds_ib_try_reuse_ibmr(struct rds_ib_mr_pool *pool)
{
struct rds_ib_mr *ibmr = NULL;
int iter = 0;
if (atomic_read(&pool->dirty_count) >= pool->max_items_soft / 10)
queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
while (1) {
ibmr = rds_ib_reuse_mr(pool);
if (ibmr)
return ibmr;
if (atomic_inc_return(&pool->item_count) <= pool->max_items)
break;
atomic_dec(&pool->item_count);
if (++iter > 2) {
if (pool->pool_type == RDS_IB_MR_8K_POOL)
rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_depleted);
else
rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_depleted);
return ERR_PTR(-EAGAIN);
}
/* We do have some empty MRs. Flush them out. */
if (pool->pool_type == RDS_IB_MR_8K_POOL)
rds_ib_stats_inc(s_ib_rdma_mr_8k_pool_wait);
else
rds_ib_stats_inc(s_ib_rdma_mr_1m_pool_wait);
rds_ib_flush_mr_pool(pool, 0, &ibmr);
if (ibmr)
return ibmr;
}
return ibmr;
}
static void rds_ib_mr_pool_flush_worker(struct work_struct *work)
{
struct rds_ib_mr_pool *pool = container_of(work, struct rds_ib_mr_pool, flush_worker.work);
rds_ib_flush_mr_pool(pool, 0, NULL);
}
void rds_ib_free_mr(void *trans_private, int invalidate)
{
struct rds_ib_mr *ibmr = trans_private;
struct rds_ib_mr_pool *pool = ibmr->pool;
struct rds_ib_device *rds_ibdev = ibmr->device;
rdsdebug("RDS/IB: free_mr nents %u\n", ibmr->sg_len);
/* Return it to the pool's free list */
if (rds_ibdev->use_fastreg)
rds_ib_free_frmr_list(ibmr);
else
rds_ib_free_fmr_list(ibmr);
atomic_add(ibmr->sg_len, &pool->free_pinned);
atomic_inc(&pool->dirty_count);
/* If we've pinned too many pages, request a flush */
if (atomic_read(&pool->free_pinned) >= pool->max_free_pinned ||
atomic_read(&pool->dirty_count) >= pool->max_items / 5)
queue_delayed_work(rds_ib_mr_wq, &pool->flush_worker, 10);
if (invalidate) {
if (likely(!in_interrupt())) {
rds_ib_flush_mr_pool(pool, 0, NULL);
} else {
/* We get here if the user created a MR marked
* as use_once and invalidate at the same time.
*/
queue_delayed_work(rds_ib_mr_wq,
&pool->flush_worker, 10);
}
}
rds_ib_dev_put(rds_ibdev);
}
void rds_ib_flush_mrs(void)
{
struct rds_ib_device *rds_ibdev;
down_read(&rds_ib_devices_lock);
list_for_each_entry(rds_ibdev, &rds_ib_devices, list) {
if (rds_ibdev->mr_8k_pool)
rds_ib_flush_mr_pool(rds_ibdev->mr_8k_pool, 0, NULL);
if (rds_ibdev->mr_1m_pool)
rds_ib_flush_mr_pool(rds_ibdev->mr_1m_pool, 0, NULL);
}
up_read(&rds_ib_devices_lock);
}
void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
struct rds_sock *rs, u32 *key_ret,
struct rds_connection *conn)
{
struct rds_ib_device *rds_ibdev;
struct rds_ib_mr *ibmr = NULL;
struct rds_ib_connection *ic = NULL;
int ret;
rds_ibdev = rds_ib_get_device(rs->rs_bound_addr.s6_addr32[3]);
if (!rds_ibdev) {
ret = -ENODEV;
goto out;
}
if (conn)
ic = conn->c_transport_data;
if (!rds_ibdev->mr_8k_pool || !rds_ibdev->mr_1m_pool) {
ret = -ENODEV;
goto out;
}
if (rds_ibdev->use_fastreg)
ibmr = rds_ib_reg_frmr(rds_ibdev, ic, sg, nents, key_ret);
else
ibmr = rds_ib_reg_fmr(rds_ibdev, sg, nents, key_ret);
if (IS_ERR(ibmr)) {
ret = PTR_ERR(ibmr);
pr_warn("RDS/IB: rds_ib_get_mr failed (errno=%d)\n", ret);
} else {
return ibmr;
}
out:
if (rds_ibdev)
rds_ib_dev_put(rds_ibdev);
return ERR_PTR(ret);
}
void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *pool)
{
cancel_delayed_work_sync(&pool->flush_worker);
rds_ib_flush_mr_pool(pool, 1, NULL);
WARN_ON(atomic_read(&pool->item_count));
WARN_ON(atomic_read(&pool->free_pinned));
kfree(pool);
}
struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *rds_ibdev,
int pool_type)
{
struct rds_ib_mr_pool *pool;
pool = kzalloc(sizeof(*pool), GFP_KERNEL);
if (!pool)
return ERR_PTR(-ENOMEM);
pool->pool_type = pool_type;
init_llist_head(&pool->free_list);
init_llist_head(&pool->drop_list);
init_llist_head(&pool->clean_list);
mutex_init(&pool->flush_lock);
init_waitqueue_head(&pool->flush_wait);
INIT_DELAYED_WORK(&pool->flush_worker, rds_ib_mr_pool_flush_worker);
if (pool_type == RDS_IB_MR_1M_POOL) {
/* +1 allows for unaligned MRs */
pool->fmr_attr.max_pages = RDS_MR_1M_MSG_SIZE + 1;
pool->max_items = rds_ibdev->max_1m_mrs;
} else {
/* pool_type == RDS_IB_MR_8K_POOL */
pool->fmr_attr.max_pages = RDS_MR_8K_MSG_SIZE + 1;
pool->max_items = rds_ibdev->max_8k_mrs;
}
pool->max_free_pinned = pool->max_items * pool->fmr_attr.max_pages / 4;
pool->fmr_attr.max_maps = rds_ibdev->fmr_max_remaps;
pool->fmr_attr.page_shift = PAGE_SHIFT;
pool->max_items_soft = rds_ibdev->max_mrs * 3 / 4;
pool->use_fastreg = rds_ibdev->use_fastreg;
return pool;
}
int rds_ib_mr_init(void)
{
rds_ib_mr_wq = alloc_workqueue("rds_mr_flushd", WQ_MEM_RECLAIM, 0);
if (!rds_ib_mr_wq)
return -ENOMEM;
return 0;
}
/* By the time this is called all the IB devices should have been torn down and
* had their pools freed. As each pool is freed its work struct is waited on,
* so the pool flushing work queue should be idle by the time we get here.
*/
void rds_ib_mr_exit(void)
{
destroy_workqueue(rds_ib_mr_wq);
}
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