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yaml
---
r: 309768
b: refs/heads/master
c: ce2d52c
h: refs/heads/master
v: v3
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Doug Ledford authored and Linus Torvalds committed Jun 1, 2012
1 parent ae2963e commit 77d6b46
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Showing 2 changed files with 82 additions and 24 deletions.
2 changes: 1 addition & 1 deletion [refs]
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Original file line number Diff line number Diff line change
@@ -1,2 +1,2 @@
---
refs/heads/master: 7820b0715b6fb1378fab41b27fb7aa3950852cb7
refs/heads/master: ce2d52cc1364a22fc1a161781e60ee3cbb499a6d
104 changes: 81 additions & 23 deletions trunk/ipc/mqueue.c
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Original file line number Diff line number Diff line change
Expand Up @@ -69,6 +69,7 @@ struct mqueue_inode_info {
wait_queue_head_t wait_q;

struct rb_root msg_tree;
struct posix_msg_tree_node *node_cache;
struct mq_attr attr;

struct sigevent notify;
Expand Down Expand Up @@ -134,15 +135,20 @@ static int msg_insert(struct msg_msg *msg, struct mqueue_inode_info *info)
else
p = &(*p)->rb_right;
}
leaf = kzalloc(sizeof(*leaf), GFP_ATOMIC);
if (!leaf)
return -ENOMEM;
rb_init_node(&leaf->rb_node);
INIT_LIST_HEAD(&leaf->msg_list);
if (info->node_cache) {
leaf = info->node_cache;
info->node_cache = NULL;
} else {
leaf = kmalloc(sizeof(*leaf), GFP_ATOMIC);
if (!leaf)
return -ENOMEM;
rb_init_node(&leaf->rb_node);
INIT_LIST_HEAD(&leaf->msg_list);
info->qsize += sizeof(*leaf);
}
leaf->priority = msg->m_type;
rb_link_node(&leaf->rb_node, parent, p);
rb_insert_color(&leaf->rb_node, &info->msg_tree);
info->qsize += sizeof(struct posix_msg_tree_node);
insert_msg:
info->attr.mq_curmsgs++;
info->qsize += msg->m_ts;
Expand Down Expand Up @@ -177,22 +183,30 @@ static inline struct msg_msg *msg_get(struct mqueue_inode_info *info)
return NULL;
}
leaf = rb_entry(parent, struct posix_msg_tree_node, rb_node);
if (list_empty(&leaf->msg_list)) {
if (unlikely(list_empty(&leaf->msg_list))) {
pr_warn_once("Inconsistency in POSIX message queue, "
"empty leaf node but we haven't implemented "
"lazy leaf delete!\n");
rb_erase(&leaf->rb_node, &info->msg_tree);
info->qsize -= sizeof(struct posix_msg_tree_node);
kfree(leaf);
if (info->node_cache) {
info->qsize -= sizeof(*leaf);
kfree(leaf);
} else {
info->node_cache = leaf;
}
goto try_again;
} else {
msg = list_first_entry(&leaf->msg_list,
struct msg_msg, m_list);
list_del(&msg->m_list);
if (list_empty(&leaf->msg_list)) {
rb_erase(&leaf->rb_node, &info->msg_tree);
info->qsize -= sizeof(struct posix_msg_tree_node);
kfree(leaf);
if (info->node_cache) {
info->qsize -= sizeof(*leaf);
kfree(leaf);
} else {
info->node_cache = leaf;
}
}
}
info->attr.mq_curmsgs--;
Expand Down Expand Up @@ -235,6 +249,7 @@ static struct inode *mqueue_get_inode(struct super_block *sb,
info->qsize = 0;
info->user = NULL; /* set when all is ok */
info->msg_tree = RB_ROOT;
info->node_cache = NULL;
memset(&info->attr, 0, sizeof(info->attr));
info->attr.mq_maxmsg = min(ipc_ns->mq_msg_max,
ipc_ns->mq_msg_default);
Expand Down Expand Up @@ -367,6 +382,7 @@ static void mqueue_evict_inode(struct inode *inode)
spin_lock(&info->lock);
while ((msg = msg_get(info)) != NULL)
free_msg(msg);
kfree(info->node_cache);
spin_unlock(&info->lock);

/* Total amount of bytes accounted for the mqueue */
Expand Down Expand Up @@ -964,7 +980,8 @@ SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
struct mqueue_inode_info *info;
ktime_t expires, *timeout = NULL;
struct timespec ts;
int ret;
struct posix_msg_tree_node *new_leaf = NULL;
int ret = 0;

if (u_abs_timeout) {
int res = prepare_timeout(u_abs_timeout, &expires, &ts);
Expand Down Expand Up @@ -1012,39 +1029,60 @@ SYSCALL_DEFINE5(mq_timedsend, mqd_t, mqdes, const char __user *, u_msg_ptr,
msg_ptr->m_ts = msg_len;
msg_ptr->m_type = msg_prio;

/*
* msg_insert really wants us to have a valid, spare node struct so
* it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will
* fall back to that if necessary.
*/
if (!info->node_cache)
new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL);

spin_lock(&info->lock);

if (!info->node_cache && new_leaf) {
/* Save our speculative allocation into the cache */
rb_init_node(&new_leaf->rb_node);
INIT_LIST_HEAD(&new_leaf->msg_list);
info->node_cache = new_leaf;
info->qsize += sizeof(*new_leaf);
new_leaf = NULL;
} else {
kfree(new_leaf);
}

if (info->attr.mq_curmsgs == info->attr.mq_maxmsg) {
if (filp->f_flags & O_NONBLOCK) {
spin_unlock(&info->lock);
ret = -EAGAIN;
} else {
wait.task = current;
wait.msg = (void *) msg_ptr;
wait.state = STATE_NONE;
ret = wq_sleep(info, SEND, timeout, &wait);
/*
* wq_sleep must be called with info->lock held, and
* returns with the lock released
*/
goto out_free;
}
if (ret < 0)
free_msg(msg_ptr);
} else {
receiver = wq_get_first_waiter(info, RECV);
if (receiver) {
pipelined_send(info, msg_ptr, receiver);
} else {
/* adds message to the queue */
if (msg_insert(msg_ptr, info)) {
free_msg(msg_ptr);
ret = -ENOMEM;
spin_unlock(&info->lock);
goto out_fput;
}
ret = msg_insert(msg_ptr, info);
if (ret)
goto out_unlock;
__do_notify(info);
}
inode->i_atime = inode->i_mtime = inode->i_ctime =
CURRENT_TIME;
spin_unlock(&info->lock);
ret = 0;
}
out_unlock:
spin_unlock(&info->lock);
out_free:
if (ret)
free_msg(msg_ptr);
out_fput:
fput(filp);
out:
Expand All @@ -1063,6 +1101,7 @@ SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
struct ext_wait_queue wait;
ktime_t expires, *timeout = NULL;
struct timespec ts;
struct posix_msg_tree_node *new_leaf = NULL;

if (u_abs_timeout) {
int res = prepare_timeout(u_abs_timeout, &expires, &ts);
Expand Down Expand Up @@ -1098,7 +1137,26 @@ SYSCALL_DEFINE5(mq_timedreceive, mqd_t, mqdes, char __user *, u_msg_ptr,
goto out_fput;
}

/*
* msg_insert really wants us to have a valid, spare node struct so
* it doesn't have to kmalloc a GFP_ATOMIC allocation, but it will
* fall back to that if necessary.
*/
if (!info->node_cache)
new_leaf = kmalloc(sizeof(*new_leaf), GFP_KERNEL);

spin_lock(&info->lock);

if (!info->node_cache && new_leaf) {
/* Save our speculative allocation into the cache */
rb_init_node(&new_leaf->rb_node);
INIT_LIST_HEAD(&new_leaf->msg_list);
info->node_cache = new_leaf;
info->qsize += sizeof(*new_leaf);
} else {
kfree(new_leaf);
}

if (info->attr.mq_curmsgs == 0) {
if (filp->f_flags & O_NONBLOCK) {
spin_unlock(&info->lock);
Expand Down

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