Module Name: src
Committed By: riastradh
Date: Wed Jan 13 02:19:09 UTC 2021
Modified Files:
src/sys/kern: kern_threadpool.c
Log Message:
threadpool(9): Make threadpool_percpu_ref_remote non-sleepable.
Needed for threadpool-based workqueue_enqueue to run in interrupt
context.
To generate a diff of this commit:
cvs rdiff -u -r1.19 -r1.20 src/sys/kern/kern_threadpool.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/kern_threadpool.c
diff -u src/sys/kern/kern_threadpool.c:1.19 src/sys/kern/kern_threadpool.c:1.20
--- src/sys/kern/kern_threadpool.c:1.19 Mon Sep 7 01:08:27 2020
+++ src/sys/kern/kern_threadpool.c Wed Jan 13 02:19:08 2021
@@ -1,4 +1,4 @@
-/* $NetBSD: kern_threadpool.c,v 1.19 2020/09/07 01:08:27 riastradh Exp $ */
+/* $NetBSD: kern_threadpool.c,v 1.20 2021/01/13 02:19:08 riastradh Exp $ */
/*-
* Copyright (c) 2014, 2018 The NetBSD Foundation, Inc.
@@ -81,7 +81,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: kern_threadpool.c,v 1.19 2020/09/07 01:08:27 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: kern_threadpool.c,v 1.20 2021/01/13 02:19:08 riastradh Exp $");
#include <sys/types.h>
#include <sys/param.h>
@@ -644,10 +644,16 @@ threadpool_percpu_ref_remote(struct thre
{
struct threadpool **poolp, *pool;
- percpu_traverse_enter();
+ /*
+ * As long as xcalls are blocked -- e.g., by kpreempt_disable
+ * -- the percpu object will not be swapped and destroyed. We
+ * can't write to it, because the data may have already been
+ * moved to a new buffer, but we can safely read from it.
+ */
+ kpreempt_disable();
poolp = percpu_getptr_remote(pool_percpu->tpp_percpu, ci);
pool = *poolp;
- percpu_traverse_exit();
+ kpreempt_enable();
return pool;
}
