On Wed, Dec 2, 2009 at 3:02 PM, Ulrich Windl <ulrich.wi...@rz.uni-regensburg.de> wrote: > On 2 Dec 2009 at 10:55, Erez Zilber wrote: > >> I'd like to make some changes in the logging in open-iscsi. The >> current status is as follows: >> >> kernel modules: >> >> * We use iscsi_cls_session_printk & iscsi_cls_conn_printk in >> scsi_transport_iscsi.c. They are sometimes wrapped by macros (e.g. >> ISCSI_DBG_TRANS_SESSION). These macros use KERN_INFO and are >> controlled by module parameters. >> >> * We use iscsi_session_printk & iscsi_conn_printk for the rest of the >> kernel code.These macros wrap iscsi_cls_session_printk & >> iscsi_cls_conn_printk accordingly. They are sometimes wrapped by >> macros (e.g. ISCSI_SW_TCP_DBG). These macros use KERN_INFO and are >> controlled by module parameters. >> >> * We sometimes use printk calls. >> >> userspace: >> >> We use log_warning, log_error & log_debug. They depend on the logging >> level that we use (0-8). if (log_level > level), the log is sent to >> syslog with the appropriate log level (LOG_WARNING/LOG_ERR/LOG_DEBUG). >> >> My motivation: with the current logging mechanism, if an error occurs, >> I'm unable to tell exactly what happened. The default logging level is >> too low. Increasing it affects performance. Another problem is that >> open-iscsi has too many logging mechanisms. >> >> I suggest that: >> 1. For kernel modules, we will have 'events' (or any better name that > > I'd call them "contexts" or "event sources". > >> you suggest) like 'session', 'conn', 'eh', 'cmd' etc. For each event, >> we will have a logging level. For example, the user may want to set >> the 'conn' event to 'DEBUG'. It means that we will print all conn >> related logs that are DEBUG and above (e.g. WARNING, ERROR). >> 2. For userspace code, we could do the same (i.e. have events and a >> log level per event). >> 3. Userspace logging uses the 'daemon' facility. This should >> definitely be the default, but we should allow the user to use another >> facility. The motivation for doing so is that if we want to send all >> iscsid logs to a separate file, we can set it to 'local2' for example >> (instead of 'daemon'). >> >> Comments? > > What I'd wish: For most messages, especially if informational messages are > enabled, it's not clear what type of severity a message has (i.e. debug, info, > warning, error, fatal error). I'd wish the severity would be obvious from the > message.
I agree. > > I once wrote some code to do something like that. Showing some calling > examples > might make it obvious: > > message(MSG_TYPE_DEBUG, __LINE__, my_step, instance, > "min_pause=%ld\n", > min_pause); > > message(MSG_TYPE_ERROR, __LINE__, my_step, instance, > "Incompatible alert state: file %s, ID %06lx\n", > state_file, state.id); > > message(MSG_TYPE_INFO, __LINE__, my_step, instance, > "OS error (%s: %s)\n", > state_file, strerror(last_errno)); > > message(MSG_TYPE_FATAL, __LINE__, my_step, instance, > "No memory for state file %s\n", > file); > > message(MSG_TYPE_WARN, __LINE__, my_step, instance, > "file \"%s\" exceeded size threshold\n", > msg_file); > > My "instance" is what you called "event"; "step" are steps in processing > something > (an integer), and __LINE__ is just handy if "Instance" includes the source > file. Yes. It would be nice if we had the function + line number for each log. I'm not sure that I understand the meaning of 'step'. Here's an example (to make sure that I got you right): if you send a PDU, you can print multiple messages while preparing & sending the PDU, each with its own step number. For example: "(1) allocating PDU" "(2) init PDU" "(3) sending PDU" "(4) PDU was sent" Is this what you mean? Erez -- You received this message because you are subscribed to the Google Groups "open-iscsi" group. To post to this group, send email to open-is...@googlegroups.com. To unsubscribe from this group, send email to open-iscsi+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/open-iscsi?hl=en.
