Module Name: src
Committed By: riastradh
Date: Sat Aug 1 02:14:43 UTC 2020
Modified Files:
src/share/man/man9: workqueue.9
src/sys/kern: subr_workqueue.c
src/sys/sys: workqueue.h
Log Message:
New workqueue flag WQ_FPU.
Arranges kthread_fpu_enter/exit around calls to the worker. Saves
cost over explicit calls to kthread_fpu_enter/exit in the worker by
only doing it once, since there's often a high cost to flushing the
icache and zeroing the fpu registers.
As proposed on tech-kern:
https://mail-index.netbsd.org/tech-kern/2020/06/20/msg026524.html
To generate a diff of this commit:
cvs rdiff -u -r1.12 -r1.13 src/share/man/man9/workqueue.9
cvs rdiff -u -r1.37 -r1.38 src/sys/kern/subr_workqueue.c
cvs rdiff -u -r1.10 -r1.11 src/sys/sys/workqueue.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/share/man/man9/workqueue.9
diff -u src/share/man/man9/workqueue.9:1.12 src/share/man/man9/workqueue.9:1.13
--- src/share/man/man9/workqueue.9:1.12 Thu Dec 28 07:00:52 2017
+++ src/share/man/man9/workqueue.9 Sat Aug 1 02:14:43 2020
@@ -1,4 +1,4 @@
-.\" $NetBSD: workqueue.9,v 1.12 2017/12/28 07:00:52 ozaki-r Exp $
+.\" $NetBSD: workqueue.9,v 1.13 2020/08/01 02:14:43 riastradh Exp $
.\"
.\" Copyright (c)2005 YAMAMOTO Takashi,
.\" All rights reserved.
@@ -83,6 +83,11 @@ The highest IPL at which this workqueue
The value of 0 indicates a standard create operation, however the following
flags may be bitwise ORed together:
.Bl -tag -width WQ_MPSAFE
+.It Dv WQ_FPU
+Specifies that the kthread must be allowed to use any machine-dependent
+per-CPU floating-point units or SIMD vector units, as in
+.Xr kthread_fpu_enter 9 / Xr kthread_fpu_exit 9 ,
+when it executes the worker function.u
.It Dv WQ_MPSAFE
Specifies that the workqueue is multiprocessor safe and does its own locking;
otherwise the kernel lock will be held while processing work.
Index: src/sys/kern/subr_workqueue.c
diff -u src/sys/kern/subr_workqueue.c:1.37 src/sys/kern/subr_workqueue.c:1.38
--- src/sys/kern/subr_workqueue.c:1.37 Wed Jun 13 05:26:12 2018
+++ src/sys/kern/subr_workqueue.c Sat Aug 1 02:14:43 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_workqueue.c,v 1.37 2018/06/13 05:26:12 ozaki-r Exp $ */
+/* $NetBSD: subr_workqueue.c,v 1.38 2020/08/01 02:14:43 riastradh Exp $ */
/*-
* Copyright (c)2002, 2005, 2006, 2007 YAMAMOTO Takashi,
@@ -27,7 +27,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_workqueue.c,v 1.37 2018/06/13 05:26:12 ozaki-r Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_workqueue.c,v 1.38 2020/08/01 02:14:43 riastradh Exp $");
#include <sys/param.h>
#include <sys/cpu.h>
@@ -112,10 +112,13 @@ workqueue_worker(void *cookie)
{
struct workqueue *wq = cookie;
struct workqueue_queue *q;
+ int s;
/* find the workqueue of this kthread */
q = workqueue_queue_lookup(wq, curlwp->l_cpu);
+ if (wq->wq_flags & WQ_FPU)
+ s = kthread_fpu_enter();
for (;;) {
/*
* we violate abstraction of SIMPLEQ.
@@ -141,6 +144,8 @@ workqueue_worker(void *cookie)
}
mutex_exit(&q->q_mutex);
}
+ if (wq->wq_flags & WQ_FPU)
+ kthread_fpu_exit(s);
}
static void
Index: src/sys/sys/workqueue.h
diff -u src/sys/sys/workqueue.h:1.10 src/sys/sys/workqueue.h:1.11
--- src/sys/sys/workqueue.h:1.10 Thu Dec 28 07:00:52 2017
+++ src/sys/sys/workqueue.h Sat Aug 1 02:14:43 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: workqueue.h,v 1.10 2017/12/28 07:00:52 ozaki-r Exp $ */
+/* $NetBSD: workqueue.h,v 1.11 2020/08/01 02:14:43 riastradh Exp $ */
/*-
* Copyright (c)2002, 2005 YAMAMOTO Takashi,
@@ -47,6 +47,7 @@ struct workqueue;
#define WQ_MPSAFE 0x01
#define WQ_PERCPU 0x02
+#define WQ_FPU 0x04
int workqueue_create(struct workqueue **, const char *,
void (*)(struct work *, void *), void *, pri_t, int, int);
