android_kernel_xiaomi_sm8350/net/rds/ib_rdma.c
Chris Mason 6fa70da608 rds: recycle FMRs through lockless lists
FRM allocation and recycling is performance critical and fairly lock
intensive.  The current code has a per connection lock that all
processes bang on and it becomes a major bottleneck on large systems.

This changes things to use a number of cmpxchg based lists instead,
allowing us to go through the whole FMR lifecycle without locking inside
RDS.

Zach Brown pointed out that our usage of cmpxchg for xlist removal is
racey if someone manages to remove and add back an FMR struct into the list
while another CPU can see the FMR's address at the head of the list.

The second CPU might assume the list hasn't changed when in fact any
number of operations might have happened in between the deletion and
reinsertion.

This commit maintains a per cpu count of CPUs that are currently
in xlist removal, and establishes a grace period to make sure that
nobody can see an entry we have just removed from the list.

Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-09-08 18:15:28 -07:00

792 lines
20 KiB
C

/*
* Copyright (c) 2006 Oracle. 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 "rds.h"
#include "ib.h"
#include "xlist.h"
static DEFINE_PER_CPU(unsigned long, clean_list_grace);
#define CLEAN_LIST_BUSY_BIT 0
/*
* This is stored as mr->r_trans_private.
*/
struct rds_ib_mr {
struct rds_ib_device *device;
struct rds_ib_mr_pool *pool;
struct ib_fmr *fmr;
struct xlist_head xlist;
/* unmap_list is for freeing */
struct list_head unmap_list;
unsigned int remap_count;
struct scatterlist *sg;
unsigned int sg_len;
u64 *dma;
int sg_dma_len;
};
/*
* Our own little FMR pool
*/
struct rds_ib_mr_pool {
struct mutex flush_lock; /* serialize fmr invalidate */
struct work_struct flush_worker; /* flush worker */
atomic_t item_count; /* total # of MRs */
atomic_t dirty_count; /* # dirty of MRs */
struct xlist_head drop_list; /* MRs that have reached their max_maps limit */
struct xlist_head free_list; /* unused MRs */
struct xlist_head clean_list; /* global unused & unamapped MRs */
wait_queue_head_t flush_wait;
atomic_t free_pinned; /* memory pinned by free MRs */
unsigned long max_items;
unsigned long max_items_soft;
unsigned long max_free_pinned;
struct ib_fmr_attr fmr_attr;
};
static int rds_ib_flush_mr_pool(struct rds_ib_mr_pool *pool, int free_all, struct rds_ib_mr **);
static void rds_ib_teardown_mr(struct rds_ib_mr *ibmr);
static void rds_ib_mr_pool_flush_worker(struct work_struct *work);
static struct rds_ib_device *rds_ib_get_device(__be32 ipaddr)
{
struct rds_ib_device *rds_ibdev;
struct rds_ib_ipaddr *i_ipaddr;
list_for_each_entry(rds_ibdev, &rds_ib_devices, list) {
rcu_read_lock();
list_for_each_entry_rcu(i_ipaddr, &rds_ibdev->ipaddr_list, list) {
if (i_ipaddr->ipaddr == ipaddr) {
atomic_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) {
synchronize_rcu();
kfree(to_free);
}
}
int rds_ib_update_ipaddr(struct rds_ib_device *rds_ibdev, __be32 ipaddr)
{
struct rds_ib_device *rds_ibdev_old;
rds_ibdev_old = rds_ib_get_device(ipaddr);
if (rds_ibdev_old) {
rds_ib_remove_ipaddr(rds_ibdev_old, ipaddr);
rds_ib_dev_put(rds_ibdev_old);
}
return rds_ib_add_ipaddr(rds_ibdev, ipaddr);
}
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_irq(&rds_ibdev->spinlock);
list_add_tail(&ic->ib_node, &rds_ibdev->conn_list);
spin_unlock_irq(&rds_ibdev->spinlock);
spin_unlock_irq(&ib_nodev_conns_lock);
ic->rds_ibdev = rds_ibdev;
atomic_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_conns(struct list_head *list, spinlock_t *list_lock)
{
struct rds_ib_connection *ic, *_ic;
LIST_HEAD(tmp_list);
/* avoid calling conn_destroy with irqs off */
spin_lock_irq(list_lock);
list_splice(list, &tmp_list);
INIT_LIST_HEAD(list);
spin_unlock_irq(list_lock);
list_for_each_entry_safe(ic, _ic, &tmp_list, ib_node)
rds_conn_destroy(ic->conn);
}
struct rds_ib_mr_pool *rds_ib_create_mr_pool(struct rds_ib_device *rds_ibdev)
{
struct rds_ib_mr_pool *pool;
pool = kzalloc(sizeof(*pool), GFP_KERNEL);
if (!pool)
return ERR_PTR(-ENOMEM);
INIT_XLIST_HEAD(&pool->free_list);
INIT_XLIST_HEAD(&pool->drop_list);
INIT_XLIST_HEAD(&pool->clean_list);
mutex_init(&pool->flush_lock);
init_waitqueue_head(&pool->flush_wait);
INIT_WORK(&pool->flush_worker, rds_ib_mr_pool_flush_worker);
pool->fmr_attr.max_pages = fmr_message_size;
pool->fmr_attr.max_maps = rds_ibdev->fmr_max_remaps;
pool->fmr_attr.page_shift = PAGE_SHIFT;
pool->max_free_pinned = rds_ibdev->max_fmrs * fmr_message_size / 4;
/* We never allow more than max_items MRs to be allocated.
* When we exceed more than max_items_soft, we start freeing
* items more aggressively.
* Make sure that max_items > max_items_soft > max_items / 2
*/
pool->max_items_soft = rds_ibdev->max_fmrs * 3 / 4;
pool->max_items = rds_ibdev->max_fmrs;
return pool;
}
void rds_ib_get_mr_info(struct rds_ib_device *rds_ibdev, struct rds_info_rdma_connection *iinfo)
{
struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
iinfo->rdma_mr_max = pool->max_items;
iinfo->rdma_mr_size = pool->fmr_attr.max_pages;
}
void rds_ib_destroy_mr_pool(struct rds_ib_mr_pool *pool)
{
cancel_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);
}
static void refill_local(struct rds_ib_mr_pool *pool, struct xlist_head *xl,
struct rds_ib_mr **ibmr_ret)
{
struct xlist_head *ibmr_xl;
ibmr_xl = xlist_del_head_fast(xl);
*ibmr_ret = list_entry(ibmr_xl, struct rds_ib_mr, xlist);
}
static inline struct rds_ib_mr *rds_ib_reuse_fmr(struct rds_ib_mr_pool *pool)
{
struct rds_ib_mr *ibmr = NULL;
struct xlist_head *ret;
unsigned long *flag;
preempt_disable();
flag = &__get_cpu_var(clean_list_grace);
set_bit(CLEAN_LIST_BUSY_BIT, flag);
ret = xlist_del_head(&pool->clean_list);
if (ret)
ibmr = list_entry(ret, struct rds_ib_mr, xlist);
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();
}
}
static struct rds_ib_mr *rds_ib_alloc_fmr(struct rds_ib_device *rds_ibdev)
{
struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
struct rds_ib_mr *ibmr = NULL;
int err = 0, iter = 0;
while (1) {
ibmr = rds_ib_reuse_fmr(pool);
if (ibmr)
return ibmr;
/* No clean MRs - now we have the choice of either
* allocating a fresh MR up to the limit imposed by the
* driver, or flush any dirty unused MRs.
* We try to avoid stalling in the send path if possible,
* so we allocate as long as we're allowed to.
*
* We're fussy with enforcing the FMR limit, though. If the driver
* tells us we can't use more than N fmrs, we shouldn't start
* arguing with it */
if (atomic_inc_return(&pool->item_count) <= pool->max_items)
break;
atomic_dec(&pool->item_count);
if (++iter > 2) {
rds_ib_stats_inc(s_ib_rdma_mr_pool_depleted);
return ERR_PTR(-EAGAIN);
}
/* We do have some empty MRs. Flush them out. */
rds_ib_stats_inc(s_ib_rdma_mr_pool_wait);
rds_ib_flush_mr_pool(pool, 0, &ibmr);
if (ibmr)
return ibmr;
}
ibmr = kzalloc_node(sizeof(*ibmr), GFP_KERNEL, rdsibdev_to_node(rds_ibdev));
if (!ibmr) {
err = -ENOMEM;
goto out_no_cigar;
}
memset(ibmr, 0, sizeof(*ibmr));
ibmr->fmr = ib_alloc_fmr(rds_ibdev->pd,
(IB_ACCESS_LOCAL_WRITE |
IB_ACCESS_REMOTE_READ |
IB_ACCESS_REMOTE_WRITE|
IB_ACCESS_REMOTE_ATOMIC),
&pool->fmr_attr);
if (IS_ERR(ibmr->fmr)) {
err = PTR_ERR(ibmr->fmr);
ibmr->fmr = NULL;
printk(KERN_WARNING "RDS/IB: ib_alloc_fmr failed (err=%d)\n", err);
goto out_no_cigar;
}
rds_ib_stats_inc(s_ib_rdma_mr_alloc);
return ibmr;
out_no_cigar:
if (ibmr) {
if (ibmr->fmr)
ib_dealloc_fmr(ibmr->fmr);
kfree(ibmr);
}
atomic_dec(&pool->item_count);
return ERR_PTR(err);
}
static int rds_ib_map_fmr(struct rds_ib_device *rds_ibdev, struct rds_ib_mr *ibmr,
struct scatterlist *sg, unsigned int nents)
{
struct ib_device *dev = rds_ibdev->dev;
struct scatterlist *scat = sg;
u64 io_addr = 0;
u64 *dma_pages;
u32 len;
int page_cnt, sg_dma_len;
int i, j;
int ret;
sg_dma_len = ib_dma_map_sg(dev, sg, nents,
DMA_BIDIRECTIONAL);
if (unlikely(!sg_dma_len)) {
printk(KERN_WARNING "RDS/IB: dma_map_sg failed!\n");
return -EBUSY;
}
len = 0;
page_cnt = 0;
for (i = 0; i < sg_dma_len; ++i) {
unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
if (dma_addr & ~PAGE_MASK) {
if (i > 0)
return -EINVAL;
else
++page_cnt;
}
if ((dma_addr + dma_len) & ~PAGE_MASK) {
if (i < sg_dma_len - 1)
return -EINVAL;
else
++page_cnt;
}
len += dma_len;
}
page_cnt += len >> PAGE_SHIFT;
if (page_cnt > fmr_message_size)
return -EINVAL;
dma_pages = kmalloc_node(sizeof(u64) * page_cnt, GFP_ATOMIC,
rdsibdev_to_node(rds_ibdev));
if (!dma_pages)
return -ENOMEM;
page_cnt = 0;
for (i = 0; i < sg_dma_len; ++i) {
unsigned int dma_len = ib_sg_dma_len(dev, &scat[i]);
u64 dma_addr = ib_sg_dma_address(dev, &scat[i]);
for (j = 0; j < dma_len; j += PAGE_SIZE)
dma_pages[page_cnt++] =
(dma_addr & PAGE_MASK) + j;
}
ret = ib_map_phys_fmr(ibmr->fmr,
dma_pages, page_cnt, io_addr);
if (ret)
goto out;
/* Success - we successfully remapped the MR, so we can
* safely tear down the old mapping. */
rds_ib_teardown_mr(ibmr);
ibmr->sg = scat;
ibmr->sg_len = nents;
ibmr->sg_dma_len = sg_dma_len;
ibmr->remap_count++;
rds_ib_stats_inc(s_ib_rdma_mr_used);
ret = 0;
out:
kfree(dma_pages);
return ret;
}
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;
}
}
static 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 */
BUG_ON(irqs_disabled());
set_page_dirty(page);
put_page(page);
}
kfree(ibmr->sg);
ibmr->sg = NULL;
ibmr->sg_len = 0;
}
}
static 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_device *rds_ibdev = ibmr->device;
struct rds_ib_mr_pool *pool = rds_ibdev->mr_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 xlist of mrs, put them all into the list_head for more processing
*/
static void xlist_append_to_list(struct xlist_head *xlist, struct list_head *list)
{
struct rds_ib_mr *ibmr;
struct xlist_head splice;
struct xlist_head *cur;
struct xlist_head *next;
splice.next = NULL;
xlist_splice(xlist, &splice);
cur = splice.next;
while (cur) {
next = cur->next;
ibmr = list_entry(cur, struct rds_ib_mr, xlist);
list_add_tail(&ibmr->unmap_list, list);
cur = next;
}
}
/*
* this takes a list head of mrs and turns it into an xlist of clusters.
* each cluster has an xlist of MR_CLUSTER_SIZE mrs that are ready for
* reuse.
*/
static void list_append_to_xlist(struct rds_ib_mr_pool *pool,
struct list_head *list, struct xlist_head *xlist,
struct xlist_head **tail_ret)
{
struct rds_ib_mr *ibmr;
struct xlist_head *cur_mr = xlist;
struct xlist_head *tail_mr = NULL;
list_for_each_entry(ibmr, list, unmap_list) {
tail_mr = &ibmr->xlist;
tail_mr->next = NULL;
cur_mr->next = tail_mr;
cur_mr = tail_mr;
}
*tail_ret = tail_mr;
}
/*
* 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.
*/
static 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, *next;
struct xlist_head clean_xlist;
struct xlist_head *clean_tail;
LIST_HEAD(unmap_list);
LIST_HEAD(fmr_list);
unsigned long unpinned = 0;
unsigned int nfreed = 0, ncleaned = 0, free_goal;
int ret = 0;
rds_ib_stats_inc(s_ib_rdma_mr_pool_flush);
if (ibmr_ret) {
DEFINE_WAIT(wait);
while(!mutex_trylock(&pool->flush_lock)) {
ibmr = rds_ib_reuse_fmr(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 (xlist_empty(&pool->clean_list))
schedule();
ibmr = rds_ib_reuse_fmr(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_fmr(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.
*/
xlist_append_to_list(&pool->drop_list, &unmap_list);
xlist_append_to_list(&pool->free_list, &unmap_list);
if (free_all)
xlist_append_to_list(&pool->clean_list, &unmap_list);
free_goal = rds_ib_flush_goal(pool, free_all);
if (list_empty(&unmap_list))
goto out;
/* String all ib_mr's onto one list and hand them to ib_unmap_fmr */
list_for_each_entry(ibmr, &unmap_list, unmap_list)
list_add(&ibmr->fmr->list, &fmr_list);
ret = ib_unmap_fmr(&fmr_list);
if (ret)
printk(KERN_WARNING "RDS/IB: ib_unmap_fmr failed (err=%d)\n", ret);
/* Now we can destroy the DMA mapping and unpin any pages */
list_for_each_entry_safe(ibmr, next, &unmap_list, unmap_list) {
unpinned += ibmr->sg_len;
__rds_ib_teardown_mr(ibmr);
if (nfreed < free_goal || ibmr->remap_count >= pool->fmr_attr.max_maps) {
rds_ib_stats_inc(s_ib_rdma_mr_free);
list_del(&ibmr->unmap_list);
ib_dealloc_fmr(ibmr->fmr);
kfree(ibmr);
nfreed++;
}
ncleaned++;
}
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 xlist 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 xlist_del_head.
*
* This is pretty unlikely, but just in case wait for an xlist grace period
* here before adding anything back into the clean list.
*/
wait_clean_list_grace();
list_append_to_xlist(pool, &unmap_list, &clean_xlist, &clean_tail);
if (ibmr_ret)
refill_local(pool, &clean_xlist, ibmr_ret);
/* refill_local may have emptied our list */
if (!xlist_empty(&clean_xlist))
xlist_add(clean_xlist.next, clean_tail, &pool->clean_list);
}
atomic_sub(unpinned, &pool->free_pinned);
atomic_sub(ncleaned, &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 ret;
}
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);
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_device *rds_ibdev = ibmr->device;
struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
rdsdebug("RDS/IB: free_mr nents %u\n", ibmr->sg_len);
/* Return it to the pool's free list */
if (ibmr->remap_count >= pool->fmr_attr.max_maps)
xlist_add(&ibmr->xlist, &ibmr->xlist, &pool->drop_list);
else
xlist_add(&ibmr->xlist, &ibmr->xlist, &pool->free_list);
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 / 10)
queue_work(rds_wq, &pool->flush_worker);
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_work(rds_wq, &pool->flush_worker);
}
}
rds_ib_dev_put(rds_ibdev);
}
void rds_ib_flush_mrs(void)
{
struct rds_ib_device *rds_ibdev;
list_for_each_entry(rds_ibdev, &rds_ib_devices, list) {
struct rds_ib_mr_pool *pool = rds_ibdev->mr_pool;
if (pool)
rds_ib_flush_mr_pool(pool, 0, NULL);
}
}
void *rds_ib_get_mr(struct scatterlist *sg, unsigned long nents,
struct rds_sock *rs, u32 *key_ret)
{
struct rds_ib_device *rds_ibdev;
struct rds_ib_mr *ibmr = NULL;
int ret;
rds_ibdev = rds_ib_get_device(rs->rs_bound_addr);
if (!rds_ibdev) {
ret = -ENODEV;
goto out;
}
if (!rds_ibdev->mr_pool) {
ret = -ENODEV;
goto out;
}
ibmr = rds_ib_alloc_fmr(rds_ibdev);
if (IS_ERR(ibmr))
return ibmr;
ret = rds_ib_map_fmr(rds_ibdev, ibmr, sg, nents);
if (ret == 0)
*key_ret = ibmr->fmr->rkey;
else
printk(KERN_WARNING "RDS/IB: map_fmr failed (errno=%d)\n", ret);
ibmr->device = rds_ibdev;
rds_ibdev = NULL;
out:
if (ret) {
if (ibmr)
rds_ib_free_mr(ibmr, 0);
ibmr = ERR_PTR(ret);
}
if (rds_ibdev)
rds_ib_dev_put(rds_ibdev);
return ibmr;
}