Module Name: src
Committed By: riastradh
Date: Thu Feb 23 03:00:53 UTC 2023
Modified Files:
src/sys/kern: subr_pcq.c
Log Message:
pcq(9): Make pcq_put a release operation, in memory ordering.
Otherwise, for example, the following assertion could fail:
/* publisher */
nusers = foo->nusers;
pcq_put(pcq, foo);
KASSERT(nusers == 0);
/* user */
foo = pcq_get(pcq);
if (foo != NULL)
atomic_inc_uint(&foo->nusers);
XXX pullup-9
XXX pullup-10
To generate a diff of this commit:
cvs rdiff -u -r1.13 -r1.14 src/sys/kern/subr_pcq.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/kern/subr_pcq.c
diff -u src/sys/kern/subr_pcq.c:1.13 src/sys/kern/subr_pcq.c:1.14
--- src/sys/kern/subr_pcq.c:1.13 Mon Feb 8 09:31:05 2021
+++ src/sys/kern/subr_pcq.c Thu Feb 23 03:00:53 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_pcq.c,v 1.13 2021/02/08 09:31:05 wiz Exp $ */
+/* $NetBSD: subr_pcq.c,v 1.14 2023/02/23 03:00:53 riastradh Exp $ */
/*-
* Copyright (c) 2009, 2019 The NetBSD Foundation, Inc.
@@ -34,7 +34,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_pcq.c,v 1.13 2021/02/08 09:31:05 wiz Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_pcq.c,v 1.14 2023/02/23 03:00:53 riastradh Exp $");
#include <sys/param.h>
#include <sys/types.h>
@@ -116,10 +116,7 @@ pcq_put(pcq_t *pcq, void *item)
* that the caller made to the data item are globally visible
* before we put it onto the list.
*/
-#ifndef __HAVE_ATOMIC_AS_MEMBAR
- membar_producer();
-#endif
- pcq->pcq_items[op] = item;
+ atomic_store_release(&pcq->pcq_items[op], item);
/*
* Synchronization activity to wake up the consumer will ensure
