Date: Fri, 16 Dec 2016 17:41:20 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r310159 - head/sys/kern Message-ID: <201612161741.uBGHfKJx006136@repo.freebsd.org>
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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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