Hi guy,
I have strace of both tcpdump and mac-analyzer(my tool) from the router
attached.
I cannot understand why the file descriptor number is different in tcpdump
and my tool
(3 and 4) respectively.
Is this is of any significance ?
I am run both the tools on the same interface created by using iw (iw phy
phy0 .interface add phe0 ..)
Any suggestions,
please let me know.
-
Abhinav
On Fri, Apr 19, 2013 at 12:22 AM, abhinav narain
<abhinavnarai...@gmail.com>wrote:
> Hi Guy,
> This is one thing I am confused about.
>
> I am right now setting the sigprocmask
> in the callback function :
> pkt_callback(...){
> if (sigprocmask(SIG_BLOCK, &block_set, NULL) < 0) {
> perror("sigprocmask");
> exit(1);
> }
>
> ....code ...
> if (sigprocmask(SIG_UNBLOCK, &block_set, NULL) < 0) {
> perror("sigprocmask");
> exit(1);
> }
> }
>
> When I turned down all the alarms, the CPU % usage came down,
> as you were also asking to try out.
>
> I think there is lot of overhead in setting up the signal masks etc.
>
> Can i instead set the masks in the main() function before and after
> calling,
> pcap_loop(), which will avoid this overhead ?
>
> I am not sure, I think this will set the masks for the code that pcap
> runs, right ?
> and block all the signals, which pcap might be using for any purpose, if
> any.
>
> Am I right to wrap the pcap_loop() inside the sigprocmask() block, instead
> of using
> it in callback function (which I am doing now ) ?
> <pseudo code>
> sigprocmask(block) ..
> pcap_loop()
> sigprocmask(unblock) ..
> </pseudo code>
>
> How will the signals work then ?
> -
> Abhinav
>
>
>
> On Thu, Apr 18, 2013 at 9:06 AM, abhinav narain <abhinavnarai...@gmail.com
> > wrote:
>
>>
>> On Thu, Apr 18, 2013 at 8:37 AM, abhinav narain <
>> abhinavnarai...@gmail.com> wrote:
>>
>>> hi Guy,
>>>
>>> What happens if you eliminate that (and any code paths that eliminating
>>>> that breaks)?
>>>>
>>>>
>> The biggest issue for me to understand is, why is the CPU usage going up
>> when
>> two instances of the tool run simultaneously. It doesn't have high usage
>> for single instance.
>> Please let me know, if you have any suggestions where I can make
>> my headway to investigate.
>> -
>> Abhinav
>>
>>
>
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