On Mon, 2010-11-08 at 12:31 -0800, Mike Waychison wrote:

This patchset applies to v2.6.37-rc1.

The following series implements support for 'netoops', a simple driver that
will deliver kmsg logs together with machine specifics over the network.

This driver is based on code used in Google's production server environment.
We internally call the driver 'netdump', but are planning on changing the name
to 'netoops' to follow the convention set by both the mtdoops and ramoops
drivers.  We use these facilities to gather crash data from our entire fleet of
machines in a light-weight manner.  We do things this way because it
simply isn't feasible to gather full crash data off of every machine in
the wild that decides it is time to die.

Currently, this driver only supports UDP over ipv4.

In order to handle configuration, the target support in netconsole is
fixed, seperated out, and re-used by netoops.

I'm posting these patches in an effort to eventually get this sort of
functionality mainlined.  I have tried to clean this code up internally, but
there are still several unresolved issues that would need to be worked
out as of this version.  In particular:

   * I am _NOT_ happy with the remaining userland ABIs presented in this
     patchset.  Specifically the files "net_dump_now",
     "net_dump_one_shot", "netdump_fw_version", "netdump_board_name" and
     "netdump_boot_id" should be considered.  These files have been
     cobbled together by a variety of engineers over the years, and they
     aren't very pretty.  I present them none-the-less to express the
     scope of the functionality that we would like to maintain.

   * I am _NOT_ happy with the data format of the transmitted packets.  It is
     very specific to our server environment and currently:

      * is hard-coded to support both userland provided information (that may
        not be applicable to others) and

      * only supports i386 and x86_64.

I'd like to resolve each of the above issues in subsequent versions of this
patchset.  I need help in identifying what the ABI should look like in
particular.

Patchset summary
================

Patches 1 through 4 inclusive are fixes to the existing netconsole code,
adding locking consistency, fixing races and deadlocks.

Patches 5 through 14 inclusive splits the target configuration portion
of netconsole out into a new component in net/core/netpoll_targets.c.

Patches 15 through 18 inclusive are core changes to support
functionality in the netoops driver.

Patches 19 through 23 is the netoops driver itself, with different
functional aspects broken out.

 1 - netconsole: Remove unneeded reference counting
 2 - netconsole: Introduce locking over the netpoll fields
 3 - netconsole: Introduce 'enabled' state-machine
 4 - netconsole: Call netpoll_cleanup() in process context

 5 - netconsole: Wrap the list and locking in a structure
 6 - netconsole: Push configfs_subsystem into netpoll_targets
 7 - netconsole: Move netdev_notifier into netpoll_targets
 8 - netconsole: Split out netpoll_targets init/exit
 9 - netconsole: Add pointer to netpoll_targets
10 - netconsole: Rename netconsole_target -> netpoll_target
11 - netconsole: Abstract away the subsystem name
12 - netpoll: Introduce netpoll_target configs
13 - netconsole: Move setting of default ports.
14 - netpoll: Move target code into netpoll_targets.c

This much of your set looks very nice to me, but I'd like to get some
more eyeballs on the first four. Dave?

Acked-by: Matt Mackall <redacted>

-- 
Mathematics is the supreme nostalgia of our time.