Blackfin uClinux socket creation failure

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My client has an old version of uClinux, kernel 2.6.22, running on a Blackfin STAMP board. The main application is divided into 14 processes, plus there's a webserver running on the board.

The bug we're seeing, the webserver keeps running happily along while the VOIP application seems to run out of file handles and can't create new sockets. I've tried every debugging technique I know of. I have a JTAG debugger but the memory is too small for debug symbols. I can't compile with Valgrind or anything like that. Any guesses?

Thanks,

Mike

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Kristof Provost On

It's likely you've got a file descriptor leak. Valgrind isn't the best tool for tracking that down anyway.

Start by doing 'ls -lah /proc/pid/fd'. That'll show you a list of file descriptors opened (and not yet closed) by the process. If you've really got a file descriptor leak you should see a lot of entries there. It should also be immediately obvious which type of file descriptor you're leaking (file, socket, ...).

Once you know that you'll have a better idea of where in the code to look for the leak.

The fact that your file system is full may be another hint. If your application is creating a file and removing it, but not closing the file descriptor, you might have a bunch of files which you won't find in the tree but which still eat up space hanging around. In that case you'll see the file names in (the target of the symlinks in) /proc/pid/fd.