The enclosed patch implements the netdev_* error-logging macros for
network drivers. These macros have been discussed at length on the
linux-kernel and linux-netdev lists. With the v2.6.0-test6 version of
these macros, we addressed all the issues that reviewers had raised.
This is just an update for v2.6.0-test11.
As previously discussed, these macros are in demand now (e.g., for
the e1000 driver) and have essentially no impact on drivers that
don't use them.
RECAP (from previous posts):
Calls to the netdev_* macros (netdev_printk and wrappers such as
netdev_err) are intended to replace calls to printk in network device
drivers. These macros have the following characteristics:
- Same format + args as the corresponding printk call.
- Approximately the same amount of text as the corresponding printk call.
- The first arg is a pointer to the net_device struct.
- The second arg, which is a NETIF_MSG_* message level, can be used to
implement verbosity control.
- Standard message prefixes: verbose (interface name, driver name, bus ID)
during probe, or just the interface name once the device is registered.
- The current implementation just calls printk. However, the netdev_*
interface (and availability of the net_device pointer) opens the door
for logging additional information (via printk, via evlog/netlink, etc.)
as desired, with no change to driver code.
Examples:
netdev_err(netdev, RX_ERR, "No mem: dropped packet\n");
logs a message such as the following if the NETIF_MSG_RX_ERR bit is set
in netdev->msg_enable.
eth2: No mem: dropped packet
netdev_fatal(netdev, PROBE, "The EEPROM Checksum Is Not Valid\n");
or
netdev_err(netdev, ALL, "The EEPROM Checksum Is Not Valid\n");
unconditionally logs a message such as:
eth%d (e1000 0000:00:03.0): The EEPROM Checksum Is Not Valid
The message's prefix includes the driver name and bus ID because the
message is logged at probe time, before netdev is registered.
SAMPLE DRIVERS
As examples of how the netdev_* macros could be used, patches for the
v2.6.0-test11 e100, e1000, and tg3 drivers are available on request.
LINUX v2.4 SUPPORT
Since there is no v2.6-style struct device underlying the net_device,
a v2.4.23-compatible version of netdev_printk would always log the
interface name as the message prefix:
#define netdev_printk(sevlevel, netdev, msglevel, format, arg...) \
do { \
if (NETIF_MSG_##msglevel == NETIF_MSG_ALL \
|| (netdev->msg_enable & NETIF_MSG_##msglevel)) { \
printk(sevlevel "%s: " format , netdev->name , ## arg); \
} \
} while (0)
Jim Keniston
IBM Linux Technology Center
Jim Keniston wrote:
The enclosed patch implements the netdev_* error-logging macros for
network drivers. These macros have been discussed at length on the
linux-kernel and linux-netdev lists. With the v2.6.0-test6 version of
these macros, we addressed all the issues that reviewers had raised.
This is just an update for v2.6.0-test11.
As previously discussed, these macros are in demand now (e.g., for
the e1000 driver) and have essentially no impact on drivers that
don't use them.
RECAP (from previous posts):
Calls to the netdev_* macros (netdev_printk and wrappers such as
netdev_err) are intended to replace calls to printk in network device
drivers. These macros have the following characteristics:
- Same format + args as the corresponding printk call.
- Approximately the same amount of text as the corresponding printk call.
- The first arg is a pointer to the net_device struct.
- The second arg, which is a NETIF_MSG_* message level, can be used to
implement verbosity control.
- Standard message prefixes: verbose (interface name, driver name, bus ID)
during probe, or just the interface name once the device is registered.
- The current implementation just calls printk. However, the netdev_*
interface (and availability of the net_device pointer) opens the door
for logging additional information (via printk, via evlog/netlink, etc.)
as desired, with no change to driver code.
Examples:
netdev_err(netdev, RX_ERR, "No mem: dropped packet\n");
logs a message such as the following if the NETIF_MSG_RX_ERR bit is set
in netdev->msg_enable.
eth2: No mem: dropped packet
netdev_fatal(netdev, PROBE, "The EEPROM Checksum Is Not Valid\n");
or
netdev_err(netdev, ALL, "The EEPROM Checksum Is Not Valid\n");
unconditionally logs a message such as:
eth%d (e1000 0000:00:03.0): The EEPROM Checksum Is Not Valid
The message's prefix includes the driver name and bus ID because the
message is logged at probe time, before netdev is registered.
SAMPLE DRIVERS
As examples of how the netdev_* macros could be used, patches for the
v2.6.0-test11 e100, e1000, and tg3 drivers are available on request.
LINUX v2.4 SUPPORT
Since there is no v2.6-style struct device underlying the net_device,
a v2.4.23-compatible version of netdev_printk would always log the
interface name as the message prefix:
#define netdev_printk(sevlevel, netdev, msglevel, format, arg...) \
do { \
if (NETIF_MSG_##msglevel == NETIF_MSG_ALL \
|| (netdev->msg_enable & NETIF_MSG_##msglevel)) { \
printk(sevlevel "%s: " format , netdev->name , ## arg); \
} \
} while (0)
I discussed this a bit with David. My personal feelings are that I
prefer just leaving all the printk's as they are. But Linus and GregKH
have been accepting patches into other parts of the tree like this one,
and logging additional already-computer-parsed information is probably
not a bad thing long-term, so perhaps I've been being a bit of a Luddite
on this issue.
It's definitely too late for 2.6.0-testX mainline merging, until Andrew
(2.6) and Linus (2.7) re-open their respective trees, but a good first
step would be for me to merge this into the net-drivers-2.5-exp queue.
Jeff
On Fri, Dec 05, 2003 at 03:03:36PM -0500, Jeff Garzik wrote:
I discussed this a bit with David. My personal feelings are that I
prefer just leaving all the printk's as they are. But Linus and GregKH
have been accepting patches into other parts of the tree like this one,
and logging additional already-computer-parsed information is probably
not a bad thing long-term, so perhaps I've been being a bit of a Luddite
on this issue.
To be fair, the patches I've taken (dev_err and friends) are _much_
simpler than these, so accepting them was not that big of a deal. It
enabled the subsystems that have started to use them (USB and I2C) to
log better messages (we now know exactly which device caused the errors,
instead of just which driver).
So please judge this patch on its own, and feel no pressure due to the
dev_*() calls :)
thanks,
greg k-h