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authorjoel <joel@FreeBSD.org>2014-12-26 09:35:23 +0000
committerjoel <joel@FreeBSD.org>2014-12-26 09:35:23 +0000
commit4e43db302da4c346291455cc8ec61c2fd09bef34 (patch)
tree729c8fe6631224ab9899d33aa73b7d424a383b4b /share/man
parent60baa2cc2abe5733eed2eb9b2fefcbbc88267dae (diff)
downloadFreeBSD-src-4e43db302da4c346291455cc8ec61c2fd09bef34.zip
FreeBSD-src-4e43db302da4c346291455cc8ec61c2fd09bef34.tar.gz
Minor mdoc fixes.
Diffstat (limited to 'share/man')
-rw-r--r--share/man/man4/netmap.480
1 files changed, 36 insertions, 44 deletions
diff --git a/share/man/man4/netmap.4 b/share/man/man4/netmap.4
index f6ca70b..bd5f4f2 100644
--- a/share/man/man4/netmap.4
+++ b/share/man/man4/netmap.4
@@ -243,7 +243,6 @@ contains the index of the first of these free rings,
which are connected in a list (the first uint32_t of each
buffer being the index of the next buffer in the list).
A 0 indicates the end of the list.
-.Pp
.It Dv struct netmap_ring (one per ring)
.Bd -literal
struct netmap_ring {
@@ -266,7 +265,6 @@ Implements transmit and receive rings, with read/write
pointers, metadata and and an array of
.Pa slots
describing the buffers.
-.Pp
.It Dv struct netmap_slot (one per buffer)
.Bd -literal
struct netmap_slot {
@@ -367,7 +365,6 @@ are pushed to the port, and
.Va tail
may advance if further slots have become available.
Below is an example of the evolution of a TX ring:
-.Pp
.Bd -literal
after the syscall, slots between cur and tail are (a)vailable
head=cur tail
@@ -455,7 +452,6 @@ it MUST be used when the buf_idx in the slot is changed.
This can be used to implement
zero-copy forwarding, see
.Sx ZERO-COPY FORWARDING .
-.Pp
.It NS_REPORT
reports when this buffer has been transmitted.
Normally,
@@ -533,7 +529,6 @@ A file descriptor obtained through
.Pa /dev/netmap
also supports the ioctl supported by network devices, see
.Xr netintro 4 .
-.Pp
.Bl -tag -width XXXX
.It Dv NIOCGINFO
returns EINVAL if the named port does not support netmap.
@@ -541,7 +536,6 @@ Otherwise, it returns 0 and (advisory) information
about the port.
Note that all the information below can change before the
interface is actually put in netmap mode.
-.Pp
.Bl -tag -width XX
.It Pa nr_memsize
indicates the size of the
@@ -603,7 +597,6 @@ that application libraries (such as the
.Nm nm_open
indicated below) can use to indicate the specific set of rings.
In the example below, "netmap:foo" is any valid netmap port name.
-.Pp
.Bl -tag -width XXXXX
.It NR_REG_ALL_NIC "netmap:foo"
(default) all hardware ring pairs
@@ -784,7 +777,6 @@ are controlled through sysctl variables on FreeBSD
.Em ( dev.netmap.* )
and module parameters on Linux
.Em ( /sys/module/netmap_lin/parameters/* ) :
-.Pp
.Bl -tag -width indent
.It Va dev.netmap.admode: 0
Controls the use of native or emulated adapter mode.
@@ -852,42 +844,6 @@ OS primitives, see
In particular,
.Xr pthread_setaffinity_np 3
may be of use.
-.Sh CAVEATS
-No matter how fast the CPU and OS are,
-achieving line rate on 10G and faster interfaces
-requires hardware with sufficient performance.
-Several NICs are unable to sustain line rate with
-small packet sizes. Insufficient PCIe or memory bandwidth
-can also cause reduced performance.
-.Pp
-Another frequent reason for low performance is the use
-of flow control on the link: a slow receiver can limit
-the transmit speed.
-Be sure to disable flow control when running high
-speed experiments.
-.Pp
-.Ss SPECIAL NIC FEATURES
-.Nm
-is orthogonal to some NIC features such as
-multiqueue, schedulers, packet filters.
-.Pp
-Multiple transmit and receive rings are supported natively
-and can be configured with ordinary OS tools,
-such as
-.Xr ethtool
-or
-device-specific sysctl variables.
-The same goes for Receive Packet Steering (RPS)
-and filtering of incoming traffic.
-.Pp
-.Nm
-.Em does not use
-features such as
-.Em checksum offloading , TCP segmentation offloading ,
-.Em encryption , VLAN encapsulation/decapsulation ,
-etc. .
-When using netmap to exchange packets with the host stack,
-make sure to disable these features.
.Sh EXAMPLES
.Ss TEST PROGRAMS
.Nm
@@ -1065,3 +1021,39 @@ and
.Nm VALE
have been funded by the European Commission within FP7 Projects
CHANGE (257422) and OPENLAB (287581).
+.Sh CAVEATS
+No matter how fast the CPU and OS are,
+achieving line rate on 10G and faster interfaces
+requires hardware with sufficient performance.
+Several NICs are unable to sustain line rate with
+small packet sizes. Insufficient PCIe or memory bandwidth
+can also cause reduced performance.
+.Pp
+Another frequent reason for low performance is the use
+of flow control on the link: a slow receiver can limit
+the transmit speed.
+Be sure to disable flow control when running high
+speed experiments.
+.Pp
+.Ss SPECIAL NIC FEATURES
+.Nm
+is orthogonal to some NIC features such as
+multiqueue, schedulers, packet filters.
+.Pp
+Multiple transmit and receive rings are supported natively
+and can be configured with ordinary OS tools,
+such as
+.Xr ethtool
+or
+device-specific sysctl variables.
+The same goes for Receive Packet Steering (RPS)
+and filtering of incoming traffic.
+.Pp
+.Nm
+.Em does not use
+features such as
+.Em checksum offloading , TCP segmentation offloading ,
+.Em encryption , VLAN encapsulation/decapsulation ,
+etc. .
+When using netmap to exchange packets with the host stack,
+make sure to disable these features.
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