On Wed, 27 Aug 2003, Giovanni P. Tirloni wrote: > Hi, > > I've been reading about mbufs and how they're used for > holding network packets and socket buffers and the > output of 'netstat -m' for a idle machine I've here > made me curious about how FreeBSD handles it in -CURRENT. > > Why is it using so many mbufs when it's idle? My > small kwnowledge doesn't permit me to answer this > question yet ;)
The mbufs in question are (mostly) being used as receive buffers by the network drivers. With modern DMA based cards, you pre-allocate the buffers, then hand them over to the card's control. Once they're filled with packet data, the NIC informs the OS, which replaces them with new buffers. A lot of our drivers have 128 (or some power of 2) receive buffers, hence your mbuf usage. Mike "Silby" Silbersack _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-net To unsubscribe, send any mail to "[EMAIL PROTECTED]"
