svn commit: r193906 - in stable/7/sys: . amd64/linux32 contrib/pf
dev/ath/ath_hal dev/cxgb i386/linux kern sys
Konstantin Belousov
kib at FreeBSD.org
Wed Jun 10 12:07:56 UTC 2009
Author: kib
Date: Wed Jun 10 12:07:52 2009
New Revision: 193906
URL: http://svn.freebsd.org/changeset/base/193906
Log:
MFC r185647;
Several threads in a process may do vfork() simultaneously. Then, all
parent threads sleep on the parent' struct proc until corresponding
child releases the vmspace. Each sleep is interlocked with proc mutex of
the child, that triggers assertion in the sleepq_add(). The assertion
requires that at any time, all simultaneous sleepers for the channel use
the same interlock.
Silent the assertion by using conditional variable allocated in the
child. Broadcast the variable event on exec() and exit().
MFC r188750:
Adapt linux emulation to use cv for vfork wait.
Modified:
stable/7/sys/ (props changed)
stable/7/sys/amd64/linux32/linux32_machdep.c
stable/7/sys/contrib/pf/ (props changed)
stable/7/sys/dev/ath/ath_hal/ (props changed)
stable/7/sys/dev/cxgb/ (props changed)
stable/7/sys/i386/linux/linux_machdep.c
stable/7/sys/kern/kern_exec.c
stable/7/sys/kern/kern_exit.c
stable/7/sys/kern/kern_fork.c
stable/7/sys/kern/kern_proc.c
stable/7/sys/sys/proc.h
Modified: stable/7/sys/amd64/linux32/linux32_machdep.c
==============================================================================
--- stable/7/sys/amd64/linux32/linux32_machdep.c Wed Jun 10 12:03:55 2009 (r193905)
+++ stable/7/sys/amd64/linux32/linux32_machdep.c Wed Jun 10 12:07:52 2009 (r193906)
@@ -537,7 +537,7 @@ linux_vfork(struct thread *td, struct li
/* wait for the children to exit, ie. emulate vfork */
PROC_LOCK(p2);
while (p2->p_flag & P_PPWAIT)
- msleep(td->td_proc, &p2->p_mtx, PWAIT, "ppwait", 0);
+ cv_wait(&p2->p_pwait, &p2->p_mtx);
PROC_UNLOCK(p2);
return (0);
@@ -726,7 +726,7 @@ linux_clone(struct thread *td, struct li
/* wait for the children to exit, ie. emulate vfork */
PROC_LOCK(p2);
while (p2->p_flag & P_PPWAIT)
- msleep(td->td_proc, &p2->p_mtx, PWAIT, "ppwait", 0);
+ cv_wait(&p2->p_pwait, &p2->p_mtx);
PROC_UNLOCK(p2);
}
Modified: stable/7/sys/i386/linux/linux_machdep.c
==============================================================================
--- stable/7/sys/i386/linux/linux_machdep.c Wed Jun 10 12:03:55 2009 (r193905)
+++ stable/7/sys/i386/linux/linux_machdep.c Wed Jun 10 12:07:52 2009 (r193906)
@@ -376,7 +376,7 @@ linux_vfork(struct thread *td, struct li
/* wait for the children to exit, ie. emulate vfork */
PROC_LOCK(p2);
while (p2->p_flag & P_PPWAIT)
- msleep(td->td_proc, &p2->p_mtx, PWAIT, "ppwait", 0);
+ cv_wait(&p2->p_pwait, &p2->p_mtx);
PROC_UNLOCK(p2);
return (0);
@@ -581,7 +581,7 @@ linux_clone(struct thread *td, struct li
/* wait for the children to exit, ie. emulate vfork */
PROC_LOCK(p2);
while (p2->p_flag & P_PPWAIT)
- msleep(td->td_proc, &p2->p_mtx, PWAIT, "ppwait", 0);
+ cv_wait(&p2->p_pwait, &p2->p_mtx);
PROC_UNLOCK(p2);
}
Modified: stable/7/sys/kern/kern_exec.c
==============================================================================
--- stable/7/sys/kern/kern_exec.c Wed Jun 10 12:03:55 2009 (r193905)
+++ stable/7/sys/kern/kern_exec.c Wed Jun 10 12:07:52 2009 (r193906)
@@ -559,7 +559,7 @@ interpret:
p->p_flag |= P_EXEC;
if (p->p_pptr && (p->p_flag & P_PPWAIT)) {
p->p_flag &= ~P_PPWAIT;
- wakeup(p->p_pptr);
+ cv_broadcast(&p->p_pwait);
}
/*
Modified: stable/7/sys/kern/kern_exit.c
==============================================================================
--- stable/7/sys/kern/kern_exit.c Wed Jun 10 12:03:55 2009 (r193905)
+++ stable/7/sys/kern/kern_exit.c Wed Jun 10 12:07:52 2009 (r193906)
@@ -550,6 +550,7 @@ retry:
* proc lock.
*/
wakeup(p->p_pptr);
+ cv_broadcast(&p->p_pwait);
PROC_SLOCK(p->p_pptr);
sched_exit(p->p_pptr, td);
PROC_SUNLOCK(p->p_pptr);
@@ -783,6 +784,7 @@ loop:
PROC_UNLOCK(p);
tdsignal(t, NULL, SIGCHLD, p->p_ksi);
wakeup(t);
+ cv_broadcast(&p->p_pwait);
PROC_UNLOCK(t);
sx_xunlock(&proctree_lock);
return (0);
Modified: stable/7/sys/kern/kern_fork.c
==============================================================================
--- stable/7/sys/kern/kern_fork.c Wed Jun 10 12:03:55 2009 (r193905)
+++ stable/7/sys/kern/kern_fork.c Wed Jun 10 12:07:52 2009 (r193906)
@@ -744,7 +744,7 @@ again:
*/
PROC_LOCK(p2);
while (p2->p_flag & P_PPWAIT)
- msleep(p1, &p2->p_mtx, PWAIT, "ppwait", 0);
+ cv_wait(&p2->p_pwait, &p2->p_mtx);
PROC_UNLOCK(p2);
/*
Modified: stable/7/sys/kern/kern_proc.c
==============================================================================
--- stable/7/sys/kern/kern_proc.c Wed Jun 10 12:03:55 2009 (r193905)
+++ stable/7/sys/kern/kern_proc.c Wed Jun 10 12:07:52 2009 (r193906)
@@ -231,6 +231,7 @@ proc_init(void *mem, int size, int flags
bzero(&p->p_mtx, sizeof(struct mtx));
mtx_init(&p->p_mtx, "process lock", NULL, MTX_DEF | MTX_DUPOK);
mtx_init(&p->p_slock, "process slock", NULL, MTX_SPIN | MTX_RECURSE);
+ cv_init(&p->p_pwait, "ppwait");
TAILQ_INIT(&p->p_threads); /* all threads in proc */
EVENTHANDLER_INVOKE(process_init, p);
p->p_stats = pstats_alloc();
Modified: stable/7/sys/sys/proc.h
==============================================================================
--- stable/7/sys/sys/proc.h Wed Jun 10 12:03:55 2009 (r193905)
+++ stable/7/sys/sys/proc.h Wed Jun 10 12:07:52 2009 (r193906)
@@ -40,6 +40,7 @@
#include <sys/callout.h> /* For struct callout. */
#include <sys/event.h> /* For struct klist. */
+#include <sys/condvar.h>
#ifndef _KERNEL
#include <sys/filedesc.h>
#endif
@@ -598,6 +599,7 @@ struct proc {
STAILQ_HEAD(, ktr_request) p_ktr; /* (o) KTR event queue. */
LIST_HEAD(, mqueue_notifier) p_mqnotifier; /* (c) mqueue notifiers.*/
struct kdtrace_proc *p_dtrace; /* (*) DTrace-specific data. */
+ struct cv p_pwait; /* (*) wait cv for exit/exec */
};
#define p_session p_pgrp->pg_session
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