Re: Possible fix for (Re: Internet problem after recent rewrite of mbuf)

[Sarunas Vancevicius <vsarunas@xxxxxxxxxx>]

On 15:11, Tue 10 Aug 04, Matthew Dillon wrote:
> :That fixes the problem of not being able to access some
> :sites.
> 
>     Excellent.  One down!

Thanks to you!

> :Second bug:
> :
> :No wonder why my pppd is taking a lot of CPU time, just look
> :at this(output from command ktrace -p 899 ;sleep 5; ktrace
> :-C; kdump -R):
> :
> :   899 pppd     1092167829.271917 CALL  select(0x6,0xbfbffa10,0,0xbfbffa10,0)
> :   899 pppd     0.000095 RET   select 1
> :   899 pppd     0.000014 CALL  read(0x5,0x8062180,0x5e0)
> :   899 pppd     0.000024 RET   read -1 errno 35 Resource temporarily unavailable
> :   899 pppd     0.000012 CALL  select(0x6,0xbfbffa10,0,0xbfbffa10,0)
> :   899 pppd     0.000013 RET   select 1
> :   899 pppd     0.000011 CALL  read(0x5,0x8062180,0x5e0)
> :...
> :So it retries, gets an error, and keeps on retrying all the
> :time at around 34000 times a second (assuming that there are
> :2 calls: select and read, and they are repeated around
> :170000 times for duration of 5 seconds, and thats 34000
> :select() and read() per second!).
> :
> :I'm not very good programmer(hell, I cannot even be called a
> :newbie programmer). But here are possible solution:
> :-- 
> :Sarunas Vancevicius
> 
>     Well, it's definitely a bug somewhere.  Could you do me a favor and
>     track down what descriptor 5 is?  Do 'fstat -p <pid_of_pppd_process>'
>     (do another ktrace to make sure it's still descriptor 5, since the
>     descriptor might wind up being different when you restart pppd).
> 
> 					-Matt
> 					Matthew Dillon 
> 					<dillon@xxxxxxxxxxxxx>

Descriptor 5 is my serial port to which my modem is connected:


USER     CMD          PID   FD MOUNT      INUM MODE         SZ|DV R/W
root     pppd         704    5 /         40226 crw-r-----   cuaa0 rw


So why my serial modem doesn't respond to read()?

-- 
Sarunas Vancevicius