Re: [PATCH 1/4] Net device error logging, revised
From: Jim Keniston <hidden>
Date: 2003-08-27 01:10:23
Also in:
lkml
Jeff Garzik wrote:
Jim Keniston wrote:quoted
#define netdev_printk(sevlevel, netdev, msglevel, format, arg...) \ do { \ if (NETIF_MSG_##msglevel == NETIF_MSG_ALL || ((netdev)->msg_enable & NETIF_MSG_##msglevel)) { \ char pfx[40]; \ printk(sevlevel "%s: " format , make_netdev_msg_prefix(pfx, netdev) , ## arg); \ }} while (0) This would make your code bigger, but not that much bigger for the common case where the msglevel is omitted (and the 'if(...)' is optimized out)."NETIF_MSG_" is silly and should be eliminated.
From this, I infer that you think that the option to "omit" the msglevel arg --
e.g., netdev_err(dev,, "NIC is fried!\n"); /* always logged */ -- is silly. No big deal. Its sole purpose is to help keep netdev_* calls terse.
A separate "NETIF_MSG_ALL" test is not needed, because msg_enable is a bitmask. A msg_enable of 0xffffffff will naturally create a NETIF_MSG_ALL.
But how do you code a netdev_* call where you ALWAYS want the message (including netdev_printk-style prefix) logged, regardless of the value of msg_enable? That's what NETIF_MSG_ALL is for (and why it might be better called NETIF_MSG_ALWAYS)... netdev_err(dev, ALL, "NIC is fried!\n"); /* always logged */ or netdev_err(dev, ALWAYS, "NIC is fried!\n"); /* always logged */
Also, whatever mechanism is created, it needs to preserve the feature of
the existing system:
if (a quick bitmask test)
do something
And preferably "do something" is not inlined, because printk'ing --
although it may appear in a fast path during debugging -- cannot be
considered a fast path itself.
JeffSorry, I'm not sure what you're getting at here. netdev_* doesn't prevent people from using the existing netif_msg_* macros; it just provides shorthand for the (usual) case where "do something" is "printk". Jim