SO u can use the first method,write files from the kernel space..... See the hyperlink i give. Lin 2009/9/14 Leonidas . <leonidas137@xxxxxxxxx>: > > > On Mon, Sep 14, 2009 at 1:22 PM, Leonidas . <leonidas137@xxxxxxxxx> wrote: >> >> >> Hi List >> >> I have written a kernel module which implements a char device. An >> userspace app >> is supposed to get data from my module and then dump it into a file for >> further processing. >> >> The kind of data which kernel module is going to pass to userspace is >> going to be a 4K buffer, >> and the data traffic is not going to be really heavy, meaning may be a 4K >> buffer every 1 min or so. >> I am not very sure though, but certainly not heavy traffic the way they >> describe for network traffic etc. >> >> And this data needs to be logged to a file either from kernel or userspace >> and an userspace all will work >> on that data. This data needs to be logged as soon as it arrives meaning, >> I might not be able to write it to >> /proc since from module I can update /proc only when user actually >> accesses it. This data needs to be >> static in nature, meaning I get one error and I write it to a file somehow >> and user can see it anytime. >> >> I hope I have described the situation clearly. I have explored some >> mechanism like ioctls, mmaping the >> kernel buffer etc but all these would require the user module to poll or >> notified somehow by kernel that >> the data is available. I dont want the user module to poll. >> >> >> -Leo. >> > > When we do a printk it writes to kernel log buffer, correct? This is real in > time operation i.e. as soon as we do a > printk the messages get logged. Now this log file can be accesses from > /var/log/messages right? How is this done? > > I want to so something similar, so I can log my messages to a seprate file > which is going to stay around so user can > see at across reboots as well. > > > > -Leo. > > -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
