Hi,

Recently, I rewrite bcc/tools/biotop with C++ language and the source
codes of it are here
(https://github.com/HarryWei/bcc/blob/master/examples/cpp/IOMigrater.cc).
When I execute it, the processes which do synchronous I/O are not
printed out consecutively in a while(1) loop, and I also find the size
of returned BPF table is ZERO. I cannot understand it. However, when I
use bcc/tools/biotop, the outputs work good for me. Can anyone give me
some hints? Thank you in advance.

# ./IOMigrater
In file included from /virtual/main.c:3:
In file included from /lib/modules/4.7.4/build/include/linux/blkdev.h:9:
In file included from /lib/modules/4.7.4/build/include/linux/genhd.h:64:
In file included from /lib/modules/4.7.4/build/include/linux/device.h:24:
In file included from
/lib/modules/4.7.4/build/include/linux/pinctrl/devinfo.h:21:
In file included from
/lib/modules/4.7.4/build/include/linux/pinctrl/consumer.h:17:
In file included from /lib/modules/4.7.4/build/include/linux/seq_file.h:10:
/lib/modules/4.7.4/build/include/linux/fs.h:2653:9: warning:
comparison of unsigned enum expression < 0 is always false
[-Wtautological-compare]
        if (id < 0 || id >= READING_MAX_ID)
            ~~ ^ ~
1 warning generated.
Filering I/O intensive threads for 10000 microseconds
This is 0 loop and size is 0
This is 1 loop and size is 0
This is 2 loop and size is 0
This is 3 loop and size is 0
This is 4 loop and size is 0
This is 5 loop and size is 0
This is 6 loop and size is 0
This is 7 loop and size is 0
This is 8 loop and size is 0
This is 9 loop and size is 0
This is 10 loop and size is 0
This is 11 loop and size is 0
This is 12 loop and size is 0
PID 0 handles I/O for 2259014 nanoseconds.
This is 13 loop and size is 1
This is 14 loop and size is 0
This is 15 loop and size is 0
This is 16 loop and size is 0
This is 17 loop and size is 0
...


Thanks,
Weiwei Jia
_______________________________________________
iovisor-dev mailing list
[email protected]
https://lists.iovisor.org/mailman/listinfo/iovisor-dev

Reply via email to