svn commit: r310159 - head/sys/kern
Konstantin Belousov
kib at FreeBSD.org
Fri Dec 16 17:41:22 UTC 2016
Author: kib
Date: Fri Dec 16 17:41:20 2016
New Revision: 310159
URL: https://svnweb.freebsd.org/changeset/base/310159
Log:
Switch from stdatomic.h to atomic.h for kernel.
Apparently stdatomic.h implementation for gcc 4.2 on sparc64 does not
work properly. This effectively reverts r251803.
Reported and tested by: lidl
Discussed with: ed
Sponsored by: The FreeBSD Foundation
MFC after: 1 week
Modified:
head/sys/kern/kern_event.c
Modified: head/sys/kern/kern_event.c
==============================================================================
--- head/sys/kern/kern_event.c Fri Dec 16 15:45:09 2016 (r310158)
+++ head/sys/kern/kern_event.c Fri Dec 16 17:41:20 2016 (r310159)
@@ -48,7 +48,6 @@ __FBSDID("$FreeBSD$");
#include <sys/fcntl.h>
#include <sys/kthread.h>
#include <sys/selinfo.h>
-#include <sys/stdatomic.h>
#include <sys/queue.h>
#include <sys/event.h>
#include <sys/eventvar.h>
@@ -69,6 +68,7 @@ __FBSDID("$FreeBSD$");
#ifdef KTRACE
#include <sys/ktrace.h>
#endif
+#include <machine/atomic.h>
#include <vm/uma.h>
@@ -188,7 +188,7 @@ static struct filterops user_filtops = {
};
static uma_zone_t knote_zone;
-static atomic_uint kq_ncallouts = ATOMIC_VAR_INIT(0);
+static unsigned int kq_ncallouts = 0;
static unsigned int kq_calloutmax = 4 * 1024;
SYSCTL_UINT(_kern, OID_AUTO, kq_calloutmax, CTLFLAG_RW,
&kq_calloutmax, 0, "Maximum number of callouts allocated for kqueue");
@@ -672,13 +672,11 @@ filt_timerattach(struct knote *kn)
if (to < 0)
return (EINVAL);
- ncallouts = atomic_load_explicit(&kq_ncallouts, memory_order_relaxed);
do {
+ ncallouts = kq_ncallouts;
if (ncallouts >= kq_calloutmax)
return (ENOMEM);
- } while (!atomic_compare_exchange_weak_explicit(&kq_ncallouts,
- &ncallouts, ncallouts + 1, memory_order_relaxed,
- memory_order_relaxed));
+ } while (!atomic_cmpset_int(&kq_ncallouts, ncallouts, ncallouts + 1));
kn->kn_flags |= EV_CLEAR; /* automatically set */
kn->kn_status &= ~KN_DETACHED; /* knlist_add clears it */
@@ -703,7 +701,7 @@ filt_timerdetach(struct knote *kn)
callout_drain(calloutp);
free(calloutp, M_KQUEUE);
free(kn->kn_ptr.p_nexttime, M_KQUEUE);
- old = atomic_fetch_sub_explicit(&kq_ncallouts, 1, memory_order_relaxed);
+ old = atomic_fetchadd_int(&kq_ncallouts, -1);
KASSERT(old > 0, ("Number of callouts cannot become negative"));
kn->kn_status |= KN_DETACHED; /* knlist_remove sets it */
}
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