svn commit: r356293 - in head/sys: kern sys
Konstantin Belousov
kib at FreeBSD.org
Thu Jan 2 22:14:00 UTC 2020
Author: kib
Date: Thu Jan 2 22:13:59 2020
New Revision: 356293
URL: https://svnweb.freebsd.org/changeset/base/356293
Log:
Rename umtxq_check_susp() to thread_check_susp()
and make it usable outside of kern_umtx.c. To be used in several
future changes.
Discussed with: markj
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Modified:
head/sys/kern/kern_thread.c
head/sys/kern/kern_umtx.c
head/sys/sys/proc.h
Modified: head/sys/kern/kern_thread.c
==============================================================================
--- head/sys/kern/kern_thread.c Thu Jan 2 22:07:03 2020 (r356292)
+++ head/sys/kern/kern_thread.c Thu Jan 2 22:13:59 2020 (r356293)
@@ -1074,6 +1074,49 @@ thread_suspend_check(int return_instead)
return (0);
}
+/*
+ * Check for possible stops and suspensions while executing a
+ * casueword or similar transiently failing operation.
+ *
+ * The sleep argument controls whether the function can handle a stop
+ * request itself or it should return ERESTART and the request is
+ * proceed at the kernel/user boundary in ast.
+ *
+ * Typically, when retrying due to casueword(9) failure (rv == 1), we
+ * should handle the stop requests there, with exception of cases when
+ * the thread owns a kernel resource, for instance busied the umtx
+ * key, or when functions return immediately if casueword_check_susp()
+ * returned non-zero. On the other hand, retrying the whole lock
+ * operation, we better not stop there but delegate the handling to
+ * ast.
+ *
+ * If the request is for thread termination P_SINGLE_EXIT, we cannot
+ * handle it at all, and simply return EINTR.
+ */
+int
+thread_check_susp(struct thread *td, bool sleep)
+{
+ struct proc *p;
+ int error;
+
+ /*
+ * The check for TDF_NEEDSUSPCHK is racy, but it is enough to
+ * eventually break the lockstep loop.
+ */
+ if ((td->td_flags & TDF_NEEDSUSPCHK) == 0)
+ return (0);
+ error = 0;
+ p = td->td_proc;
+ PROC_LOCK(p);
+ if (p->p_flag & P_SINGLE_EXIT)
+ error = EINTR;
+ else if (P_SHOULDSTOP(p) ||
+ ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_SUSPEND)))
+ error = sleep ? thread_suspend_check(0) : ERESTART;
+ PROC_UNLOCK(p);
+ return (error);
+}
+
void
thread_suspend_switch(struct thread *td, struct proc *p)
{
Modified: head/sys/kern/kern_umtx.c
==============================================================================
--- head/sys/kern/kern_umtx.c Thu Jan 2 22:07:03 2020 (r356292)
+++ head/sys/kern/kern_umtx.c Thu Jan 2 22:13:59 2020 (r356293)
@@ -691,48 +691,6 @@ umtxq_count_pi(struct umtx_key *key, struct umtx_q **f
}
/*
- * Check for possible stops and suspensions while executing a umtx
- * locking operation.
- *
- * The sleep argument controls whether the function can handle a stop
- * request itself or it should return ERESTART and the request is
- * proceed at the kernel/user boundary in ast.
- *
- * Typically, when retrying due to casueword(9) failure (rv == 1), we
- * should handle the stop requests there, with exception of cases when
- * the thread busied the umtx key, or when functions return
- * immediately if umtxq_check_susp() returned non-zero. On the other
- * hand, retrying the whole lock operation, we better not stop there
- * but delegate the handling to ast.
- *
- * If the request is for thread termination P_SINGLE_EXIT, we cannot
- * handle it at all, and simply return EINTR.
- */
-static int
-umtxq_check_susp(struct thread *td, bool sleep)
-{
- struct proc *p;
- int error;
-
- /*
- * The check for TDF_NEEDSUSPCHK is racy, but it is enough to
- * eventually break the lockstep loop.
- */
- if ((td->td_flags & TDF_NEEDSUSPCHK) == 0)
- return (0);
- error = 0;
- p = td->td_proc;
- PROC_LOCK(p);
- if (p->p_flag & P_SINGLE_EXIT)
- error = EINTR;
- else if (P_SHOULDSTOP(p) ||
- ((p->p_flag & P_TRACED) && (td->td_dbgflags & TDB_SUSPEND)))
- error = sleep ? thread_suspend_check(0) : ERESTART;
- PROC_UNLOCK(p);
- return (error);
-}
-
-/*
* Wake up threads waiting on an userland object.
*/
@@ -1070,7 +1028,7 @@ do_lock_normal(struct thread *td, struct umutex *m, ui
return (EOWNERDEAD); /* success */
}
MPASS(rv == 1);
- rv = umtxq_check_susp(td, false);
+ rv = thread_check_susp(td, false);
if (rv != 0)
return (rv);
continue;
@@ -1111,7 +1069,7 @@ do_lock_normal(struct thread *td, struct umutex *m, ui
return (0);
}
if (rv == 1) {
- rv = umtxq_check_susp(td, false);
+ rv = thread_check_susp(td, false);
if (rv != 0)
return (rv);
}
@@ -1124,7 +1082,7 @@ do_lock_normal(struct thread *td, struct umutex *m, ui
}
/* rv == 1 but not contested, likely store failure */
- rv = umtxq_check_susp(td, false);
+ rv = thread_check_susp(td, false);
if (rv != 0)
return (rv);
}
@@ -1167,7 +1125,7 @@ do_lock_normal(struct thread *td, struct umutex *m, ui
if (rv == -1)
return (EFAULT);
if (rv == 1) {
- rv = umtxq_check_susp(td, false);
+ rv = thread_check_susp(td, false);
if (rv != 0)
return (rv);
}
@@ -1189,7 +1147,7 @@ do_lock_normal(struct thread *td, struct umutex *m, ui
umtx_key_release(&uq->uq_key);
if (error == 0)
- error = umtxq_check_susp(td, false);
+ error = thread_check_susp(td, false);
}
return (0);
@@ -1224,7 +1182,7 @@ again:
if (error == -1)
return (EFAULT);
if (error == 1) {
- error = umtxq_check_susp(td, false);
+ error = thread_check_susp(td, false);
if (error != 0)
return (error);
goto again;
@@ -1261,7 +1219,7 @@ again:
if (error == 1) {
if (old != owner)
return (EINVAL);
- error = umtxq_check_susp(td, false);
+ error = thread_check_susp(td, false);
if (error != 0)
return (error);
goto again;
@@ -1316,7 +1274,7 @@ again:
umtxq_unbusy(&key);
umtxq_unlock(&key);
umtx_key_release(&key);
- error = umtxq_check_susp(td, false);
+ error = thread_check_susp(td, false);
if (error != 0)
return (error);
goto again;
@@ -1400,7 +1358,7 @@ do_wake2_umutex(struct thread *td, struct umutex *m, u
break;
}
owner = old;
- error = umtxq_check_susp(td, false);
+ error = thread_check_susp(td, false);
}
umtxq_lock(&key);
@@ -1905,7 +1863,7 @@ do_lock_pi(struct thread *td, struct umutex *m, uint32
* to the pending signal with suspension check result.
*/
if (error == 0) {
- error = umtxq_check_susp(td, true);
+ error = thread_check_susp(td, true);
if (error != 0)
break;
}
@@ -1922,7 +1880,7 @@ do_lock_pi(struct thread *td, struct umutex *m, uint32
}
if (rv == 1) {
if (error == 0) {
- error = umtxq_check_susp(td, true);
+ error = thread_check_susp(td, true);
if (error != 0)
break;
}
@@ -1994,7 +1952,7 @@ do_lock_pi(struct thread *td, struct umutex *m, uint32
}
if (rv == 1) {
umtxq_unbusy_unlocked(&uq->uq_key);
- error = umtxq_check_susp(td, true);
+ error = thread_check_susp(td, true);
if (error != 0)
break;
@@ -2017,7 +1975,7 @@ do_lock_pi(struct thread *td, struct umutex *m, uint32
if (error != 0)
continue;
- error = umtxq_check_susp(td, false);
+ error = thread_check_susp(td, false);
if (error != 0)
break;
}
@@ -2063,7 +2021,7 @@ usrloop:
if (error == -1)
return (EFAULT);
if (error == 1) {
- error = umtxq_check_susp(td, true);
+ error = thread_check_susp(td, true);
if (error != 0)
return (error);
goto usrloop;
@@ -2150,7 +2108,7 @@ usrloop:
again:
error = casueword32(&m->m_owner, owner, &old, new_owner);
if (error == 1) {
- error = umtxq_check_susp(td, false);
+ error = thread_check_susp(td, false);
if (error == 0)
goto again;
}
@@ -2255,7 +2213,7 @@ do_lock_pp(struct thread *td, struct umutex *m, uint32
* error to not skip the last loop iteration.
*/
if (error == 0) {
- error = umtxq_check_susp(td, false);
+ error = thread_check_susp(td, false);
if (error == 0) {
if (try != 0)
error = EBUSY;
@@ -2770,7 +2728,7 @@ do_rw_rdlock(struct thread *td, struct urwlock *rwlock
umtx_key_release(&uq->uq_key);
return (0);
}
- error = umtxq_check_susp(td, true);
+ error = thread_check_susp(td, true);
if (error != 0)
break;
state = oldstate;
@@ -2806,7 +2764,7 @@ do_rw_rdlock(struct thread *td, struct urwlock *rwlock
goto sleep;
}
state = oldstate;
- error = umtxq_check_susp(td, false);
+ error = thread_check_susp(td, false);
if (error != 0)
break;
}
@@ -2818,7 +2776,7 @@ do_rw_rdlock(struct thread *td, struct urwlock *rwlock
/* state is changed while setting flags, restart */
if (!(state & wrflags)) {
umtxq_unbusy_unlocked(&uq->uq_key);
- error = umtxq_check_susp(td, true);
+ error = thread_check_susp(td, true);
if (error != 0)
break;
continue;
@@ -2886,7 +2844,7 @@ sleep:
break;
}
state = oldstate;
- error1 = umtxq_check_susp(td, false);
+ error1 = thread_check_susp(td, false);
if (error1 != 0) {
if (error == 0)
error = error1;
@@ -2948,7 +2906,7 @@ do_rw_wrlock(struct thread *td, struct urwlock *rwlock
return (0);
}
state = oldstate;
- error = umtxq_check_susp(td, true);
+ error = thread_check_susp(td, true);
if (error != 0)
break;
}
@@ -2995,7 +2953,7 @@ do_rw_wrlock(struct thread *td, struct urwlock *rwlock
goto sleep;
}
state = oldstate;
- error = umtxq_check_susp(td, false);
+ error = thread_check_susp(td, false);
if (error != 0)
break;
}
@@ -3007,7 +2965,7 @@ do_rw_wrlock(struct thread *td, struct urwlock *rwlock
if ((state & URWLOCK_WRITE_OWNER) == 0 &&
URWLOCK_READER_COUNT(state) == 0) {
umtxq_unbusy_unlocked(&uq->uq_key);
- error = umtxq_check_susp(td, false);
+ error = thread_check_susp(td, false);
if (error != 0)
break;
continue;
@@ -3070,7 +3028,7 @@ sleep:
break;
}
state = oldstate;
- error1 = umtxq_check_susp(td, false);
+ error1 = thread_check_susp(td, false);
/*
* We are leaving the URWLOCK_WRITE_WAITERS
* behind, but this should not harm the
@@ -3136,7 +3094,7 @@ do_rw_unlock(struct thread *td, struct urwlock *rwlock
error = EPERM;
goto out;
}
- error = umtxq_check_susp(td, true);
+ error = thread_check_susp(td, true);
if (error != 0)
goto out;
} else
@@ -3156,7 +3114,7 @@ do_rw_unlock(struct thread *td, struct urwlock *rwlock
error = EPERM;
goto out;
}
- error = umtxq_check_susp(td, true);
+ error = thread_check_susp(td, true);
if (error != 0)
goto out;
} else
@@ -3234,7 +3192,7 @@ again:
umtxq_remove(uq);
umtxq_unlock(&uq->uq_key);
if (rv == 1) {
- rv = umtxq_check_susp(td, true);
+ rv = thread_check_susp(td, true);
if (rv == 0)
goto again;
error = rv;
@@ -3356,7 +3314,7 @@ again:
umtx_key_release(&uq->uq_key);
if (rv == -1)
return (EFAULT);
- rv = umtxq_check_susp(td, true);
+ rv = thread_check_susp(td, true);
if (rv != 0)
return (rv);
goto again;
@@ -3416,7 +3374,7 @@ do_sem2_wake(struct thread *td, struct _usem2 *sem)
rv = casueword32(&sem->_count, count, &count,
count & ~USEM_HAS_WAITERS);
if (rv == 1) {
- rv = umtxq_check_susp(td, true);
+ rv = thread_check_susp(td, true);
if (rv != 0)
break;
}
Modified: head/sys/sys/proc.h
==============================================================================
--- head/sys/sys/proc.h Thu Jan 2 22:07:03 2020 (r356292)
+++ head/sys/sys/proc.h Thu Jan 2 22:13:59 2020 (r356293)
@@ -1144,6 +1144,7 @@ void cpu_thread_swapin(struct thread *);
void cpu_thread_swapout(struct thread *);
struct thread *thread_alloc(int pages);
int thread_alloc_stack(struct thread *, int pages);
+int thread_check_susp(struct thread *td, bool sleep);
void thread_cow_get_proc(struct thread *newtd, struct proc *p);
void thread_cow_get(struct thread *newtd, struct thread *td);
void thread_cow_free(struct thread *td);
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