From mboxrd@z Thu Jan 1 00:00:00 1970 From: chambilkethakur@gmail.com (Anuz Pratap Singh Tomar) Date: Fri, 25 Mar 2011 17:50:52 +0000 Subject: kernel space logging In-Reply-To: References: Message-ID: To: kernelnewbies@lists.kernelnewbies.org List-Id: kernelnewbies.lists.kernelnewbies.org On Fri, Mar 25, 2011 at 5:43 PM, Anand Arumugam wrote: > On Thu, Mar 24, 2011 at 5:47 PM, Greg Freemyer > wrote: > > On Tue, Mar 22, 2011 at 1:13 PM, Anand Arumugam > wrote: > >> Hello all! > >> > >> I would like to know how logging is done while the kernel is booting > >> up. More importantly I am looking for those files in the kernel source > >> that handles the logging part. Also I would like to know what gets > >> logged after the kernel is up and running. > >> > >> Thanks for your time. > >> > >> cheers, > >> -anand. > > > > Are you talking about the logs you see when you run dmesg? > > > > You are aware the kernel maintains a ring buffer that all printk's go > into. > > > > Then there are API's that let userspace track the buffer and put the > > messages into on disk logs. > > > > dmesg just dumps out the ring buffer queue. > > > > The userspace API to the ring buffer is syslog(). > > > > So during bootup I _assume_ the kernel is just logging to the ring > > buffer, and then when the system is operational enough, userspace gets > > all the boot messages out of the kernel via syslog() and puts them to > > on disk log files. > > > > It's not too magic. > > > > Greg > > > > I was looking for the logging framework used by the kernel developers. > Not just the dmesg logs. > > hope this helps: http://www.ibm.com/developerworks/linux/library/l-kernel-logging-apis/?ca=drs- this is a tool and good read otherwise: http://www.cs.huji.ac.il/~etsman/klogger/ -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.kernelnewbies.org/pipermail/kernelnewbies/attachments/20110325/d7025e08/attachment.html