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| author | Michael Kerrisk <mtk.manpages@gmail.com> | 2017-02-19 09:19:57 +0100 |
|---|---|---|
| committer | Michael Kerrisk <mtk.manpages@gmail.com> | 2017-04-20 16:44:45 +0200 |
| commit | a99fa5fb93420d2c9f0f54c6543dd39941b1c73d (patch) | |
| tree | d957f9c35ad8c1aa677602cfc8eca1eed167f063 /man7 | |
| parent | b7f97e8ea5768a7da5b1ec0fea0f14e72feb1357 (diff) | |
| download | man-pages-a99fa5fb93420d2c9f0f54c6543dd39941b1c73d.tar.gz | |
socket.7: Enhance the description of SO_INCOMING_CPU
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
Diffstat (limited to 'man7')
| -rw-r--r-- | man7/socket.7 | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/man7/socket.7 b/man7/socket.7 index 15bff45b1a..81e15b663b 100644 --- a/man7/socket.7 +++ b/man7/socket.7 @@ -504,8 +504,12 @@ setsockopt(fd, SOL_SOCKET, SO_INCOMING_CPU, &cpu, &len); .fi .in -The typical use case is one listener per RX queue, as the associated listener -should accept only flows handled in softirq by the same CPU. +Because all of the packets for a single stream +(i.e., all packets for the same 4-tuple) +arrive on the single RX queue that is associated with a particular CPU, +the typical use case is to employ one listening process per RX queue, +with the incoming flow being handled by a listener +on the same CPU that is handling the RX queue. This provides optimal NUMA behavior and keeps CPU caches hot. .TP .B SO_KEEPALIVE |