On Wed, Feb 5, 2014 at 9:51 PM, Mike Frysinger <[email protected]> wrote: > On Wednesday, February 05, 2014 16:41:15 Cristian Ionescu-Idbohrn wrote: >> On Wed, 5 Feb 2014, Denys Vlasenko wrote: >> > On Tue, Feb 4, 2014 at 8:48 PM, Cristian Ionescu-Idbohrn > <[email protected]> wrote: >> > > The backside of this, IIRC, is that udhcpc will eat up huge chunks of >> > > CPU parsing "uninteresting" packets, on "heavy" loaded networks. >> > >> > udhcpc does not listen to the network after it established a lease. >> >> As I said, it's not the wait to get a lease that is a problem but the >> high CPU load (parsing packets). > > what is using the high CPU load ? not udhcpc, but the kernel itself ? > > what kernel are you using exactly ? what arch ?
udhcpc uses raw socket to receive *all IPv4 packets* when it waits for initial DHCP server responses. Therefore, it can get potentially lots and lots of unrelated packets, and needs to check and discard each of them. I am not convinced this is a problem in practice. I want to avoid fixing a non-existing problem. We "fixed" it once with BPF filter, creating a real problem: for some people, presence of that filter broke udhcpc. (For me it worked). _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
