RepoMirrors
/
mars
mirror of https://github.com/schoebel/mars
1
0
Fork 0
Code Issues Packages Projects Releases Wiki Activity

infra: replace say rwlock by rwsem

This commit is contained in:
Thomas Schoebel-Theuer 2017-12-11 10:04:07 +01:00 committed by Thomas Schoebel-Theuer
parent f7e9619ab7
commit f2b1e61812
1 changed files with 51 additions and 37 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

88
kernel/brick_say.c
View File

@ -127,7 +127,7 @@ EXPORT_SYMBOL_GPL(default_channel);
static struct say_channel *channel_list = NULL;
static rwlock_t say_lock = __RW_LOCK_UNLOCKED(say_lock);
static DECLARE_RWSEM(say_mutex);
static struct task_struct *say_thread = NULL;
@ -159,9 +159,11 @@ struct say_channel *find_channel(const void *id)
{
struct say_channel *res = default_channel;
struct say_channel *ch;
unsigned long flags;
read_lock_irqsave(&say_lock, flags);
if (cannot_schedule())
return res;
down_read(&say_mutex);
for (ch = channel_list; ch; ch = ch->ch_next) {
int i;
for (i = 0; i < ch->ch_id_max; i++) {
@ -172,7 +174,7 @@ struct say_channel *find_channel(const void *id)
}
}
found:
read_unlock_irqrestore(&say_lock, flags);
up_read(&say_mutex);
return res;
}
@ -194,9 +196,11 @@ void _remove_binding(struct task_struct *whom)
void bind_to_channel(struct say_channel *ch, struct task_struct *whom)
{
int i;
unsigned long flags;
write_lock_irqsave(&say_lock, flags);
if (cannot_schedule())
return;
down_write(&say_mutex);
_remove_binding(whom);
for (i = 0; i < ch->ch_id_max; i++) {
if (!ch->ch_ids[i]) {
@ -211,11 +215,11 @@ void bind_to_channel(struct say_channel *ch, struct task_struct *whom)
}
done:
write_unlock_irqrestore(&say_lock, flags);
up_write(&say_mutex);
return;
err:
write_unlock_irqrestore(&say_lock, flags);
up_write(&say_mutex);
say_to(default_channel, SAY_ERROR, "ID overflow for thread '%s'\n", whom->comm);
}
@ -225,9 +229,11 @@ struct say_channel *get_binding(struct task_struct *whom)
{
struct say_channel *ch;
int i;
unsigned long flags;
read_lock_irqsave(&say_lock, flags);
if (cannot_schedule())
return NULL;
down_read(&say_mutex);
for (ch = channel_list; ch; ch = ch->ch_next) {
for (i = 0; i < ch->ch_id_max; i++) {
if (ch->ch_ids[i] == whom) {
@ -237,7 +243,7 @@ struct say_channel *get_binding(struct task_struct *whom)
}
ch = NULL;
found:
read_unlock_irqrestore(&say_lock, flags);
up_read(&say_mutex);
return ch;
}
EXPORT_SYMBOL_GPL(get_binding);
@ -246,9 +252,11 @@ void remove_binding_from(struct say_channel *ch, struct task_struct *whom)
{
bool found = false;
int i;
unsigned long flags;
write_lock_irqsave(&say_lock, flags);
if (cannot_schedule())
return;
down_write(&say_mutex);
for (i = 0; i < ch->ch_id_max; i++) {
if (ch->ch_ids[i] == whom) {
ch->ch_ids[i] = NULL;
@ -259,17 +267,18 @@ void remove_binding_from(struct say_channel *ch, struct task_struct *whom)
if (!found) {
_remove_binding(whom);
}
write_unlock_irqrestore(&say_lock, flags);
up_write(&say_mutex);
}
EXPORT_SYMBOL_GPL(remove_binding_from);
void remove_binding(struct task_struct *whom)
{
unsigned long flags;
if (cannot_schedule())
return;
write_lock_irqsave(&say_lock, flags);
down_write(&say_mutex);
_remove_binding(whom);
write_unlock_irqrestore(&say_lock, flags);
up_write(&say_mutex);
}
EXPORT_SYMBOL_GPL(remove_binding);
@ -286,13 +295,15 @@ EXPORT_SYMBOL_GPL(rollover_channel);
void rollover_all(void)
{
struct say_channel *ch;
unsigned long flags;
read_lock_irqsave(&say_lock, flags);
if (cannot_schedule())
return;
down_read(&say_mutex);
for (ch = channel_list; ch; ch = ch->ch_next) {
ch->ch_rollover = true;
}
read_unlock_irqrestore(&say_lock, flags);
up_read(&say_mutex);
}
EXPORT_SYMBOL_GPL(rollover_all);
@ -315,19 +326,20 @@ void _del_channel(struct say_channel *ch)
struct say_channel *tmp;
struct say_channel **_tmp;
int i, j;
unsigned long flags;
if (!ch)
return;
if (cannot_schedule())
return;
write_lock_irqsave(&say_lock, flags);
down_write(&say_mutex);
for (_tmp = &channel_list; (tmp = *_tmp) != NULL; _tmp = &tmp->ch_next) {
if (tmp == ch) {
*_tmp = tmp->ch_next;
break;
}
}
write_unlock_irqrestore(&say_lock, flags);
up_write(&say_mutex);
for (i = 0; i < MAX_SAY_CLASS; i++) {
for (j = 0; j < 2; j++) {
@ -417,23 +429,27 @@ struct say_channel *make_channel(const char *name, bool must_exist)
{
struct say_channel *res = NULL;
struct say_channel *ch;
unsigned long flags;
read_lock_irqsave(&say_lock, flags);
if (cannot_schedule()) {
printk(KERN_ERR "trying to make channel in atomic\n");
return NULL;
}
down_read(&say_mutex);
for (ch = channel_list; ch; ch = ch->ch_next) {
if (!strcmp(ch->ch_name, name)) {
res = ch;
break;
}
}
read_unlock_irqrestore(&say_lock, flags);
up_read(&say_mutex);
if (unlikely(!res)) {
res = _make_channel(name, must_exist);
if (unlikely(!res))
goto done;
write_lock_irqsave(&say_lock, flags);
down_write(&say_mutex);
for (ch = channel_list; ch; ch = ch->ch_next) {
if (ch != res && unlikely(!strcmp(ch->ch_name, name))) {
@ -447,7 +463,7 @@ struct say_channel *make_channel(const char *name, bool must_exist)
channel_list = res;
race_found:
write_unlock_irqrestore(&say_lock, flags);
up_write(&say_mutex);
}
done:
@ -820,8 +836,6 @@ void treat_channel(struct say_channel *ch, int class)
static
int _say_thread(void *data)
{
unsigned long flags;
while (!kthread_should_stop()) {
struct say_channel *ch;
int i;
@ -830,36 +844,36 @@ int _say_thread(void *data)
say_dirty = false;
restart_rollover:
read_lock_irqsave(&say_lock, flags);
down_read(&say_mutex);
for (ch = channel_list; ch; ch = ch->ch_next) {
if (ch->ch_rollover && ch->ch_status_written > 0) {
read_unlock_irqrestore(&say_lock, flags);
up_read(&say_mutex);
_rollover_channel(ch);
goto restart_rollover;
}
}
read_unlock_irqrestore(&say_lock, flags);
up_read(&say_mutex);
restart:
read_lock_irqsave(&say_lock, flags);
down_read(&say_mutex);
for (ch = channel_list; ch; ch = ch->ch_next) {
int start = 0;
if (!ch->ch_is_dir)
start = SAY_TOTAL;
for (i = start; i < MAX_SAY_CLASS; i++) {
if (ch->ch_index[i] > 0) {
read_unlock_irqrestore(&say_lock, flags);
up_read(&say_mutex);
treat_channel(ch, i);
goto restart;
}
}
if (ch->ch_delete) {
read_unlock_irqrestore(&say_lock, flags);
up_read(&say_mutex);
_del_channel(ch);
goto restart;
}
}
read_unlock_irqrestore(&say_lock, flags);
up_read(&say_mutex);
}
return 0;