[src/trunk]: src/share/man/man4 add WM_RX_PROCESS_LIMIT_DEFAULT and WM_RX_INT...

[knakahara <knakahara%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/10a1b6928193
branches:  trunk
changeset: 351888:10a1b6928193
user:      knakahara <knakahara%NetBSD.org@localhost>
date:      Fri Mar 03 10:44:25 2017 +0000

description:
add WM_RX_PROCESS_LIMIT_DEFAULT and WM_RX_INTR_PROCESS_LIMIT_DEFAULT description

pointed out by pgoyette@n.o, thanks.

diffstat:

 share/man/man4/wm.4 |  38 ++++++++++++++++++++++++++++++++++++--
 1 files changed, 36 insertions(+), 2 deletions(-)

diffs (66 lines):

diff -r 3314c3604d64 -r 10a1b6928193 share/man/man4/wm.4
--- a/share/man/man4/wm.4       Fri Mar 03 09:29:57 2017 +0000
+++ b/share/man/man4/wm.4       Fri Mar 03 10:44:25 2017 +0000
@@ -1,4 +1,4 @@
-.\"    $NetBSD: wm.4,v 1.31 2014/09/03 14:36:45 msaitoh Exp $
+.\"    $NetBSD: wm.4,v 1.32 2017/03/03 10:44:25 knakahara Exp $
 .\"
 .\" Copyright 2002, 2003 Wasabi Systems, Inc.
 .\" All rights reserved.
@@ -33,7 +33,7 @@
 .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 .\" POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd September 3, 2014
+.Dd March 3, 2017
 .Dt WM 4
 .Os
 .Sh NAME
@@ -42,6 +42,9 @@
 .Sh SYNOPSIS
 .Cd "wm* at pci? dev ? function ?"
 .Pp
+.Cd options WM_RX_PROCESS_LIMIT_DEFAULT
+.Cd options WM_RX_INTR_PROCESS_LIMIT_DEFAULT
+.Pp
 Configuration of PHYs may also be necessary.
 See
 .Xr mii 4 .
@@ -167,6 +170,37 @@
 for information on how to enable this feature.
 .\" .Sh DIAGNOSTICS
 .\" XXX to be done.
+.Sh OPTIONS
+.Bl -tag -width WM_RX_INTR_PROCESS_LIMIT_DEFAULT -offset 3n
+.It Dv WM_RX_PROCESS_LIMIT_DEFAULT
+The maxinum number of received packets which processed in each
+.Xr softint 9
+context. This option only effects for multiqueue. The value range
+is between zero to UINT_MAX. The default value is 100.
+When you increase this value, receive latency would increase and
+receive throughput would increase.
+.It Dv WM_RX_INTR_PROCESS_LIMIT_DEFAULT
+The maxinum number of received packets which processed in each
+hardware interrupt context. This option only effects for multiqueue.
+The value range is between zero to UINT_MAX. The default value is 0.
+When you increase this value, receive latency would decrease and
+receive throughput would decrease.
+.El
+.Pp
+Setting
+.Em WM_RX_INTR_PROCESS_LIMIT_DEFAULT
+to zero means so-called polling mode, that is, once an interrupt occurs,
+the driver keep processing received packets until
+.Em WM_RX_PROCESS_LIMIT_DEFAULT .
+Polling mode increases latency a little, however it supresses
+performance degration at high load very well.
+.Pp
+If you want to disable polling mode (to use traditional interrupt
+driven mode), you should set
+.Em WM_RX_PROCESS_LIMIT_DEFAULT
+zero and set
+.Em WM_RX_INTR_PROCESS_LIMIT_DEFAULT
+UINT_MAX.
 .Sh SEE ALSO
 .Xr arp 4 ,
 .Xr ifmedia 4 ,