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From: Satoru M. <sat...@hd...> - 2011-12-16 22:15:31
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Sometimes network packets are dropped for some reason. In enterprise systems which require strict RAS functionality, we must know the reason why it happened and explain it to our customers even if using TCP. When we investigate the incidents, at first we try to find out whether the problem is in the server(kernel, application) or else (router, hub etc). And next we try to find out which layer (application/middleware/kernel(IP/TCP/UDP/..)etc.) the problem occurs. In application layer, user applications and/or middlewares usually save logs if they dropped packets. In kernel layer, with this tracepoint, we are able to know whether the kernel(TCP layer) send packets successfully or not. With a combination of them, we can find out whether the problem is in the server or not. Satoru Moriya (2): tcp: refactor tcp_retransmit_skb() for a single return point tcp: add tracepoint for tcp retransmission include/trace/events/tcp.h | 35 +++++++++++++++++++++++++++++++++++ net/core/net-traces.c | 1 + net/ipv4/tcp_output.c | 34 ++++++++++++++++++++++++---------- 3 files changed, 60 insertions(+), 10 deletions(-) create mode 100644 include/trace/events/tcp.h -- 1.7.6.4 |