diff options
Diffstat (limited to 'Documentation/networking/netlink_mmap.txt')
-rw-r--r-- | Documentation/networking/netlink_mmap.txt | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/Documentation/networking/netlink_mmap.txt b/Documentation/networking/netlink_mmap.txt index 1c2dab409625..9bd0f5211e9a 100644 --- a/Documentation/networking/netlink_mmap.txt +++ b/Documentation/networking/netlink_mmap.txt | |||
@@ -54,7 +54,7 @@ it will use an allocated socket buffer as usual and the contents will be | |||
54 | copied to the ring on transmission, nullifying most of the performance gains. | 54 | copied to the ring on transmission, nullifying most of the performance gains. |
55 | Dumps of kernel databases automatically support memory mapped I/O. | 55 | Dumps of kernel databases automatically support memory mapped I/O. |
56 | 56 | ||
57 | Conversion of the transmit path involves changing message contruction to | 57 | Conversion of the transmit path involves changing message construction to |
58 | use memory from the TX ring instead of (usually) a buffer declared on the | 58 | use memory from the TX ring instead of (usually) a buffer declared on the |
59 | stack and setting up the frame header approriately. Optionally poll() can | 59 | stack and setting up the frame header approriately. Optionally poll() can |
60 | be used to wait for free frames in the TX ring. | 60 | be used to wait for free frames in the TX ring. |
@@ -65,8 +65,8 @@ Structured and definitions for using memory mapped I/O are contained in | |||
65 | RX and TX rings | 65 | RX and TX rings |
66 | ---------------- | 66 | ---------------- |
67 | 67 | ||
68 | Each ring contains a number of continous memory blocks, containing frames of | 68 | Each ring contains a number of continuous memory blocks, containing frames of |
69 | fixed size dependant on the parameters used for ring setup. | 69 | fixed size dependent on the parameters used for ring setup. |
70 | 70 | ||
71 | Ring: [ block 0 ] | 71 | Ring: [ block 0 ] |
72 | [ frame 0 ] | 72 | [ frame 0 ] |
@@ -80,7 +80,7 @@ Ring: [ block 0 ] | |||
80 | [ frame 2 * n + 1 ] | 80 | [ frame 2 * n + 1 ] |
81 | 81 | ||
82 | The blocks are only visible to the kernel, from the point of view of user-space | 82 | The blocks are only visible to the kernel, from the point of view of user-space |
83 | the ring just contains the frames in a continous memory zone. | 83 | the ring just contains the frames in a continuous memory zone. |
84 | 84 | ||
85 | The ring parameters used for setting up the ring are defined as follows: | 85 | The ring parameters used for setting up the ring are defined as follows: |
86 | 86 | ||
@@ -91,7 +91,7 @@ struct nl_mmap_req { | |||
91 | unsigned int nm_frame_nr; | 91 | unsigned int nm_frame_nr; |
92 | }; | 92 | }; |
93 | 93 | ||
94 | Frames are grouped into blocks, where each block is a continous region of memory | 94 | Frames are grouped into blocks, where each block is a continuous region of memory |
95 | and holds nm_block_size / nm_frame_size frames. The total number of frames in | 95 | and holds nm_block_size / nm_frame_size frames. The total number of frames in |
96 | the ring is nm_frame_nr. The following invariants hold: | 96 | the ring is nm_frame_nr. The following invariants hold: |
97 | 97 | ||
@@ -113,7 +113,7 @@ Some parameters are constrained, specifically: | |||
113 | 113 | ||
114 | - nm_frame_nr must equal the actual number of frames as specified above. | 114 | - nm_frame_nr must equal the actual number of frames as specified above. |
115 | 115 | ||
116 | When the kernel can't allocate phsyically continous memory for a ring block, | 116 | When the kernel can't allocate physically continuous memory for a ring block, |
117 | it will fall back to use physically discontinous memory. This might affect | 117 | it will fall back to use physically discontinous memory. This might affect |
118 | performance negatively, in order to avoid this the nm_frame_size parameter | 118 | performance negatively, in order to avoid this the nm_frame_size parameter |
119 | should be chosen to be as small as possible for the required frame size and | 119 | should be chosen to be as small as possible for the required frame size and |