Messages in this thread | | | Date | Wed, 10 Jan 2007 19:33:41 +0900 | From | Keiichi KII <> | Subject | Re: [RFC][PATCH -mm take2 3/5] add interface for netconsole using sysfs |
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>> create a sysfs entry for netconsole in /sys/class/misc. >> This entry has elements related to netconsole as follows. >> You can change configuration of netconsole(writable attributes such as IP >> address, port number and so on) and check current configuration of netconsole. >> >> -+- /sys/class/misc/ >> |-+- netconsole/ >> |-+- port1/ >> | |--- id [r--r--r--] unique port id >> | |--- remove [-w-------] if you write something to "remove", >> | | this port is removed. >> > IMHO this kind of "magic side effect" is a misuse of sysfs. and would > make proper locking > impossible. How do you deal with the dangling reference to the > netconsole object?
I manage the reference by using a list. If you write something to "remove", firstly the port entry is removed from sysfs and then the reference is removed from the list and a resource of the port is freed.
> f= open (... netconsole/port1/remove") > write(f, "", 1) > sleep(2) > write(f, "", 1) .... this probably would crash... > > > Maybe having a state variable/sysfs file so you could setup the port and > turn it on/off with write.
You are right. When I tested above program, my machine crashed.
I'm going to rethink the interface for netconsole.
Thanks for your comments. -- Keiichi KII NEC Corporation OSS Promotion Center E-mail: k-keiichi@bx.jp.nec.com
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