d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

lockmgr: add a helper for reading the lock value

Browse Source
This commit is contained in:
Mateusz Guzik 2020-07-21 14:39:20 +00:00
parent 7377c1df84
commit bdb6d824f4
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=363392
2 changed files with 18 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

34
sys/kern/kern_lock.c
View File

@ -140,7 +140,7 @@ LK_CAN_SHARE(uintptr_t x, int flags, bool fp)
#define lockmgr_xlocked_v(v) \
(((v) & ~(LK_FLAGMASK & ~LK_SHARE)) == (uintptr_t)curthread)
#define lockmgr_xlocked(lk) lockmgr_xlocked_v((lk)->lk_lock)
#define lockmgr_xlocked(lk) lockmgr_xlocked_v(lockmgr_read_value(lk))
static void assert_lockmgr(const struct lock_object *lock, int how);
#ifdef DDB
@ -233,7 +233,7 @@ static void
lockmgr_note_exclusive_release(struct lock *lk, const char *file, int line)
{
if (LK_HOLDER(lk->lk_lock) != LK_KERNPROC) {
if (LK_HOLDER(lockmgr_read_value(lk)) != LK_KERNPROC) {
WITNESS_UNLOCK(&lk->lock_object, LOP_EXCLUSIVE, file, line);
TD_LOCKS_DEC(curthread);
}
@ -246,7 +246,7 @@ lockmgr_xholder(const struct lock *lk)
{
uintptr_t x;
x = lk->lk_lock;
x = lockmgr_read_value(lk);
return ((x & LK_SHARE) ? NULL : (struct thread *)LK_HOLDER(x));
}
@ -309,7 +309,7 @@ wakeupshlk(struct lock *lk, const char *file, int line)
wakeup_swapper = 0;
for (;;) {
x = lk->lk_lock;
x = lockmgr_read_value(lk);
if (lockmgr_sunlock_try(lk, &x))
break;
@ -318,7 +318,7 @@ wakeupshlk(struct lock *lk, const char *file, int line)
* path in order to handle wakeups correctly.
*/
sleepq_lock(&lk->lock_object);
orig_x = lk->lk_lock;
orig_x = lockmgr_read_value(lk);
retry_sleepq:
x = orig_x & (LK_ALL_WAITERS | LK_EXCLUSIVE_SPINNERS);
v = LK_UNLOCKED;
@ -515,7 +515,7 @@ lockmgr_slock_try(struct lock *lk, uintptr_t *xp, int flags, bool fp)
* waiters, if we fail to acquire the shared lock
* loop back and retry.
*/
*xp = lk->lk_lock;
*xp = lockmgr_read_value(lk);
while (LK_CAN_SHARE(*xp, flags, fp)) {
if (atomic_fcmpset_acq_ptr(&lk->lk_lock, xp,
*xp + LK_ONE_SHARER)) {
@ -603,7 +603,7 @@ lockmgr_slock_hard(struct lock *lk, u_int flags, struct lock_object *ilk,
* probabilly will need to manipulate waiters flags.
*/
sleepq_lock(&lk->lock_object);
x = lk->lk_lock;
x = lockmgr_read_value(lk);
retry_sleepq:
/*
@ -772,7 +772,7 @@ lockmgr_xlock_hard(struct lock *lk, u_int flags, struct lock_object *ilk,
* probabilly will need to manipulate waiters flags.
*/
sleepq_lock(&lk->lock_object);
x = lk->lk_lock;
x = lockmgr_read_value(lk);
retry_sleepq:
/*
@ -889,7 +889,7 @@ lockmgr_upgrade(struct lock *lk, u_int flags, struct lock_object *ilk,
tid = (uintptr_t)curthread;
_lockmgr_assert(lk, KA_SLOCKED, file, line);
v = lk->lk_lock;
v = lockmgr_read_value(lk);
x = v & LK_ALL_WAITERS;
v &= LK_EXCLUSIVE_SPINNERS;
@ -970,7 +970,7 @@ lockmgr_lock_flags(struct lock *lk, u_int flags, struct lock_object *ilk,
LOP_EXCLUSIVE, file, line, flags & LK_INTERLOCK ?
ilk : NULL);
tid = (uintptr_t)curthread;
if (lk->lk_lock == LK_UNLOCKED &&
if (lockmgr_read_value(lk) == LK_UNLOCKED &&
atomic_cmpset_acq_ptr(&lk->lk_lock, LK_UNLOCKED, tid)) {
lockmgr_note_exclusive_acquire(lk, 0, 0, file, line,
flags);
@ -1054,7 +1054,7 @@ lockmgr_xunlock_hard(struct lock *lk, uintptr_t x, u_int flags, struct lock_obje
goto out;
sleepq_lock(&lk->lock_object);
x = lk->lk_lock;
x = lockmgr_read_value(lk);
v = LK_UNLOCKED;
/*
@ -1178,7 +1178,7 @@ lockmgr_unlock(struct lock *lk)
line = __LINE__;
_lockmgr_assert(lk, KA_LOCKED, file, line);
x = lk->lk_lock;
x = lockmgr_read_value(lk);
if (__predict_true(x & LK_SHARE) != 0) {
lockmgr_note_shared_release(lk, file, line);
if (lockmgr_sunlock_try(lk, &x)) {
@ -1292,7 +1292,7 @@ __lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk,
* In order to preserve waiters flags, just spin.
*/
for (;;) {
x = lk->lk_lock;
x = lockmgr_read_value(lk);
MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0);
x &= LK_ALL_WAITERS;
if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x,
@ -1305,7 +1305,7 @@ __lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk,
break;
case LK_RELEASE:
_lockmgr_assert(lk, KA_LOCKED, file, line);
x = lk->lk_lock;
x = lockmgr_read_value(lk);
if (__predict_true(x & LK_SHARE) != 0) {
lockmgr_note_shared_release(lk, file, line);
@ -1359,7 +1359,7 @@ __lockmgr_args(struct lock *lk, u_int flags, struct lock_object *ilk,
* probabilly will need to manipulate waiters flags.
*/
sleepq_lock(&lk->lock_object);
x = lk->lk_lock;
x = lockmgr_read_value(lk);
/*
* if the lock has been released while we spun on
@ -1545,7 +1545,7 @@ _lockmgr_disown(struct lock *lk, const char *file, int line)
* In order to preserve waiters flags, just spin.
*/
for (;;) {
x = lk->lk_lock;
x = lockmgr_read_value(lk);
MPASS((x & LK_EXCLUSIVE_SPINNERS) == 0);
x &= LK_ALL_WAITERS;
if (atomic_cmpset_rel_ptr(&lk->lk_lock, tid | x,
@ -1597,7 +1597,7 @@ lockstatus(const struct lock *lk)
int ret;
ret = LK_SHARED;
x = lk->lk_lock;
x = lockmgr_read_value(lk);
v = LK_HOLDER(x);
if ((x & LK_SHARE) == 0) {

1
sys/sys/lockmgr.h
View File

@ -119,6 +119,7 @@ _lockmgr_args_rw(struct lock *lk, u_int flags, struct rwlock *ilk,
/*
* Define aliases in order to complete lockmgr KPI.
*/
#define lockmgr_read_value(lk) ((lk)->lk_lock)
#define lockmgr(lk, flags, ilk) \
_lockmgr_args((lk), (flags), (ilk), LK_WMESG_DEFAULT, \
LK_PRIO_DEFAULT, LK_TIMO_DEFAULT, LOCK_FILE, LOCK_LINE)