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Annotation of researchv8dc/netfs/NOTES, revision 1.1.1.1

1.1       root        1: /tmp/xxx looks like a 1048576 byte file, but it is all holes except for the last
                      2: block.
                      3: :;time cat /tmp/xxx > /dev/null
                      4: 0.1u 2.4s 3r    cat /tmp/xxx
                      5: :;time cat /n/debug/tmp/xxx > /dev/null
                      6: 0.2u 20.0s 66r          cat /n/debug/tmp/xxx
                      7: Thus the netfs without disk delay is running at 15887 bytes per second.
                      8: If the file is buffered in the server there is no noticable change.
                      9: Thus the slow rate is in the protocol.
                     10: ws%time cat /n/seki/tmp/__2148 > /dev/null #totally buffered in server
                     11: 0.1u 21.2s 52r          cat /n/seki/tmp/__2148
                     12: ws%time cat /n/seki/tmp/xxx > /dev/null #hole file, no buffering in server
                     13: 0.0u 20.8s 53r          cat /n/seki/tmp/xxx
                     14: ws%time cat /n/seki/tmp/xxx > /dev/null #no holes either
                     15: 0.0u 20.8s 53r          cat /n/seki/tmp/xxx
                     16: the netfs runs at bout 19784 bytes per second, with no perceptible
                     17: effect of disk or buffering at host end.
                     18: 
                     19: 1000 local fstats take about 11 seconds of system time,
                     20: while 1000 getuids take about 2.7 seconds.
                     21: 1000 remote fstats of /n/debug take 33 seconds of real time, about 10 milliseconds
                     22: a message.
                     23: 
                     24: Now if the server and setup are connected through a pipe, instead of the
                     25: network, catting the file with holes:
                     26: :;time cat m/tmp/9489 > /dev/null
                     27: 0.1u 5.1s 12r   cat m/tmp/9489
                     28: without holes:
                     29: :;:;time cat m/tmp/x > /dev/null
                     30: 0.1u 5.2s 12r   cat m/tmp/x

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