Messages in this thread Patch in this message | | | From | Satyam Sharma <> | Date | Wed, 04 Jul 2007 16:38:04 +0530 | Subject | [PATCH -mm 5/9] netconsole: Introduce dev_status member |
| |
From: Satyam Sharma <ssatyam@cse.iitk.ac.in>
[5/9] netconsole: Introduce dev_status member
Introduce a new member in netconsole_target that tracks the status (up or down) of the underlying interface network device that the specific logging target netpoll is attached to.
We then join this up with the just-introduced net_device notifier, and introduce NETDEV_UP and NETDEV_DOWN notifications. By disabling the target when the corresponding local interface is down, we save the overhead of unnecessarily disabling interrupts and calling into the netpoll stack in console->write().
Signed-off-by: Satyam Sharma <ssatyam@cse.iitk.ac.in> Cc: Keiichi Kii <k-keiichi@bx.jp.nec.com> Cc: Takayoshi Kochi <t-kochi@bq.jp.nec.com>
---
drivers/net/netconsole.c | 42 +++++++++++++++++++++++++++++++----------- 1 file changed, 31 insertions(+), 11 deletions(-)
---
diff -ruNp a/drivers/net/netconsole.c b/drivers/net/netconsole.c --- a/drivers/net/netconsole.c 2007-07-03 22:05:51.000000000 +0530 +++ b/drivers/net/netconsole.c 2007-07-04 03:04:45.000000000 +0530 @@ -63,11 +63,23 @@ static int __init option_setup(char *opt __setup("netconsole=", option_setup); #endif +/* + * Why no net_dev_is_up() in netdevice.h? The kernel could lose a lot of + * weight if only netdevice.h had the good sense to export such a function. + * Oh well ... + */ +static inline int net_dev_is_up(struct net_device *net_dev) +{ + return ((net_dev->flags & IFF_UP) == IFF_UP); +} + /** * struct netconsole_target - Represents a configured netconsole target. + * @dev_status: Tracks whether the underlying interface is up or down. * @np: The netpoll structure for this target. */ struct netconsole_target { + int dev_status; struct netpoll np; }; @@ -89,11 +101,17 @@ static int netconsole_netdev_event(struc struct net_device *dev = ptr; struct netconsole_target *nt = &default_target; - if (!(event == NETDEV_CHANGEADDR || event == NETDEV_CHANGENAME)) - goto done; + if (!(event == NETDEV_UP || event == NETDEV_DOWN || + event == NETDEV_CHANGEADDR || event == NETDEV_CHANGENAME)) + goto done; if (nt->np.dev == dev) { switch (event) { + case NETDEV_UP: + case NETDEV_DOWN: + nt->dev_status = net_dev_is_up(nt->np.dev); + break; + case NETDEV_CHANGEADDR: memcpy(nt->np.local_mac, dev->dev_addr, ETH_ALEN); break; @@ -118,16 +136,16 @@ static void write_msg(struct console *co unsigned long flags; struct netconsole_target *nt = &default_target; - local_irq_save(flags); - - for (left = len; left;) { - frag = min(left, MAX_PRINT_CHUNK); - netpoll_send_udp(&nt->np, msg, frag); - msg += frag; - left -= frag; + if (nt->dev_status) { + local_irq_save(flags); + for (left = len; left;) { + frag = min(left, MAX_PRINT_CHUNK); + netpoll_send_udp(&nt->np, msg, frag); + msg += frag; + left -= frag; + } + local_irq_restore(flags); } - - local_irq_restore(flags); } static struct console netconsole = { @@ -154,6 +172,8 @@ static int __init init_netconsole(void) if (err) goto out; + nt->dev_status = net_dev_is_up(nt->np.dev); + err = register_netdevice_notifier(&netconsole_netdev_notifier); if (err) return err; - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |