CCing dccp@xxxxxxxxxxxxxxx, since I wrote a nice description about this new toy :) Em Mon, Oct 22, 2007 at 03:24:41PM +0100, Gerrit Renker escreveu: > | perhaps one that could understand types and then could allow developers > | to ask questions like "show me all the places where the field foo of > | type bar appears" > Hopefully in the next generation of such things may be possible? I was > once stunned by a screenshot of some form of (k)gdb which took a large nested > struct apart into the nested components. This is my baby I guess :) pahole can do just that: http://oops.ghostprotocols.net:81/acme/dwarves/pahole--expand_types-struct-tcp6_sock.txt > So far very happy with "make cscope" and the excellent support that vim offers, > also tried Red Hat's sourcenav once (but took ages).o I use ctags, but I agree that cscope has more features. Ah, I'm working on some systemtap tapsets, i.e. libraries of probe routines, for networking, starting with TCP, but organized in a way that can be easily used with DCCP and other net protocols too. You need to build the kernel with CONFIG_DEBUG_INFO so that systemtap gets the required symbols (tcp_v4_rcv, etc, look in the tapsets). Take a look, I had to manually sort the output, will fix that, and there are some bugs yet as you can see with some negative nanosecond deltas, but its getting useful. Ah, the times are in nanoseconds from userspace all the way to the network device driver ("dev_out" lines), and from netif_rx or netif_receive_skb (i.e. right when the network device driver creates the packet and hands it up the network stack) to ip_rcv ("ip_in"), tcp_v4_rcv ("tcp_in") and to userspace via skb_copy_datagram_iovec ("user_in"). I'm using skb->tstamp to mark when the journey begins, so don't use it at the same time with tcpdump. I intend to record more entries, so that we can understand where the skbs are sitting. And will probably convert net/dccp/dccpprobe.c and tcpprobe to be just systemtap scripts and not part of the build process, etc. http://oops.ghostprotocols.net:81/acme/nettaps.tar.bz2 [root@doppio nettaps]# stap -I tapset/ lnlat.stp latency(ns) buffer size entry local address port remote address port avg min max avg min max - user_in 192.168.1.9 48366 216.239.51.125 5222 737982 724188 751776 195 5 386 tcp_in 192.168.1.9 48366 216.239.51.125 5222 40176 40176 40176 411 411 411 ip_in 192.168.1.9 48366 216.239.51.125 5222 13968 13968 13968 431 431 431 dev_out 192.168.1.9 48366 216.239.51.125 5222 37884 21588 54180 63 54 72 - user_in 192.168.1.9 43391 192.168.1.6 22 283830 216216 346140 56 48 64 tcp_in 192.168.1.9 43391 192.168.1.6 22 34221 24492 65232 88 80 96 ip_in 192.168.1.9 43391 192.168.1.6 22 11620 9744 14052 108 100 116 dev_out 192.168.1.9 43391 192.168.1.6 22 -2943 -870508 229992 93 66 148 - user_in 192.168.1.9 49886 207.46.108.27 1863 247464 247464 247464 8 8 8 tcp_in 192.168.1.9 49886 207.46.108.27 1863 18150 18150 18150 40 40 40 ip_in 192.168.1.9 49886 207.46.108.27 1863 5718 5718 5718 60 60 60 dev_out 192.168.1.9 49886 207.46.108.27 1863 54475 9714 146004 77 66 89 - user_in 10.11.15.126 40517 10.10.36.72 6667 60596 30912 90280 65 52 79 tcp_in 10.11.15.126 40517 10.10.36.72 6667 9258 9258 9258 111 111 111 ip_in 10.11.15.126 40517 10.10.36.72 6667 2736 2736 2736 131 131 131 dev_out 10.11.15.126 40517 10.10.36.72 6667 10026 10026 10026 52 52 52 - user_in 192.168.1.9 57815 192.168.1.2 22 401277 209832 778728 57 48 64 tcp_in 192.168.1.9 57815 192.168.1.2 22 37165 24720 72444 89 80 96 ip_in 192.168.1.9 57815 192.168.1.2 22 11777 9720 14868 109 100 116 dev_out 192.168.1.9 57815 192.168.1.2 22 60789 14052 216828 93 66 148 - user_in 192.168.1.9 44572 192.168.1.8 22 128581 -509484 451092 56 48 64 tcp_in 192.168.1.9 44572 192.168.1.8 22 31453 23088 58008 88 80 96 ip_in 192.168.1.9 44572 192.168.1.8 22 10946 9300 14256 108 100 116 dev_out 192.168.1.9 44572 192.168.1.8 22 54194 16404 215784 88 66 148 - - Arnaldo - To unsubscribe from this list: send the line "unsubscribe dccp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
