Module Name: src
Committed By: rmind
Date: Sun May 25 14:56:23 UTC 2014
Modified Files:
src/share/man/man9: pcu.9
Log Message:
pcu(9) man page: correct PCU_REENABLE description, add pcu_discard_all(),
improve some wording.
To generate a diff of this commit:
cvs rdiff -u -r1.9 -r1.10 src/share/man/man9/pcu.9
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/pcu.9
diff -u src/share/man/man9/pcu.9:1.9 src/share/man/man9/pcu.9:1.10
--- src/share/man/man9/pcu.9:1.9 Fri May 16 08:29:18 2014
+++ src/share/man/man9/pcu.9 Sun May 25 14:56:23 2014
@@ -1,4 +1,4 @@
-.\" $NetBSD: pcu.9,v 1.9 2014/05/16 08:29:18 wiz Exp $
+.\" $NetBSD: pcu.9,v 1.10 2014/05/25 14:56:23 rmind Exp $
.\"
.\" Copyright (c) 2012-2014 The NetBSD Foundation, Inc.
.\" All rights reserved.
@@ -27,7 +27,7 @@
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
.\" POSSIBILITY OF SUCH DAMAGE.
.\"
-.Dd May 15, 2014
+.Dd May 25, 2014
.Dt PCU 9
.Os
.Sh NAME
@@ -43,6 +43,8 @@
.Fn pcu_save_all "lwp_t *l"
.Ft void
.Fn pcu_discard "const pcu_ops_t *pcu" "bool valid"
+.Ft void
+.Fn pcu_discard_all "lwp_t *l"
.Ft bool
.Fn pcu_valid_p "const pcu_ops_t *pcu"
.\" -----
@@ -80,7 +82,10 @@ and has not been discarded since.
.It Dv PCU_REENABLE
Indicate that a fault reoccurred while the PCU state is loaded,
therefore PCU should be re-enabled.
-This is applicable only in some cases, e.g. ARM NEON extensions.
+This happens if LWP is context switched to another CPU and then switched
+back to the original CPU while the state on that CPU has not been changed
+by other LWPs.
+It may also happen due to instruction "bouncing" on some architectures.
.El
.It Fn pcu_state_release
Indicate to MD code that the PCU ownership by the LWP was released,
@@ -90,6 +95,7 @@ be called to reacquire the ownership.
For example, this would normally be the changing of a bit for a CPU to
trap on the execution of one of the PCU's instructions.
.El
+.\" -----
.Sh FUNCTIONS
.Bl -tag -width pcu_save_allXXX
.It Fn pcu_load
@@ -106,8 +112,11 @@ Generally, it always becomes "valid" whe
.Fn pcu_load
is called by the LWP.
Otherwise, return false.
+.It Fn pcu_discard_all
+Discard all PCU states of the given LWP; generally used by exec and exit.
.It Fn pcu_save_all
-Save all PCU states of the given LWP, so that they could be used later.
+Save all PCU states of the given LWP; generally used during new LWP
+creation so that the PCU state of the parent could be copied.
.El
.\" -----
.Sh CODE REFERENCES
@@ -117,3 +126,5 @@ is implemented within the file
.Sh HISTORY
PCU first appeared in
.Nx 6.0 .
+.Sh AUTHORS
+.An Mindaugas Rasiukevicius Aq Mt rm...@netbsd.org
