On Tue, 16 Nov 2010, Maxim Sobolev wrote:
Log: MFC r207554:Add new tunable 'net.link.ifqmaxlen' to set default send interface queue length. The default value for this parameter is 50, which is quite low for many of today's uses and the only way to modify this parameter right now is to edit if_var.h file. Also add read-only sysctl with the same name, so that it's possible to retrieve the current value.
This was quite low for yestdeay's uses (starting in about 1995), but today it is little missed since only yesterday's low-end hardware uses it. Most of today's interfaces are 1Gbps, and for this it is almost essential for the hardware to have a ring buffer with > 50 entries, so most of today's drivers ignore ifqmaxlen and set the queue length to the almost equally bogus value of the ring buffer size (-1). I set it to about 10000 instead in bge and em (10000 is too large, but fixes streaming under certain loads when hz is small).
Modified: stable/7/sys/arm/at91/if_ate.c stable/7/sys/arm/xscale/ixp425/if_npe.c stable/7/sys/contrib/dev/oltr/if_oltr.c stable/7/sys/dev/ae/if_ae.c stable/7/sys/dev/an/if_an.c stable/7/sys/dev/ar/if_ar.c stable/7/sys/dev/arl/if_arl.c stable/7/sys/dev/ath/if_ath.c stable/7/sys/dev/awi/awi.c stable/7/sys/dev/ce/if_ce.c stable/7/sys/dev/cm/smc90cx6.c stable/7/sys/dev/cnw/if_cnw.c stable/7/sys/dev/cp/if_cp.c stable/7/sys/dev/cs/if_cs.c stable/7/sys/dev/ctau/if_ct.c stable/7/sys/dev/cx/if_cx.c stable/7/sys/dev/cxgb/cxgb_main.c stable/7/sys/dev/ed/if_ed.c stable/7/sys/dev/ep/if_ep.c stable/7/sys/dev/ex/if_ex.c stable/7/sys/dev/ie/if_ie.c stable/7/sys/dev/iicbus/if_ic.c stable/7/sys/dev/ipw/if_ipw.c stable/7/sys/dev/iwi/if_iwi.c stable/7/sys/dev/le/lance.c stable/7/sys/dev/malo/if_malo.c stable/7/sys/dev/my/if_my.c stable/7/sys/dev/nxge/if_nxge.c stable/7/sys/dev/pdq/pdq_ifsubr.c stable/7/sys/dev/ppbus/if_plip.c stable/7/sys/dev/ral/rt2560.c stable/7/sys/dev/ral/rt2661.c stable/7/sys/dev/ray/if_ray.c stable/7/sys/dev/sbni/if_sbni.c stable/7/sys/dev/sbsh/if_sbsh.c stable/7/sys/dev/sn/if_sn.c stable/7/sys/dev/snc/dp83932.c stable/7/sys/dev/sr/if_sr.c stable/7/sys/dev/usb/if_aue.c stable/7/sys/dev/usb/if_axe.c stable/7/sys/dev/usb/if_cdce.c stable/7/sys/dev/usb/if_cue.c stable/7/sys/dev/usb/if_kue.c stable/7/sys/dev/usb/if_rue.c stable/7/sys/dev/usb/if_rum.c stable/7/sys/dev/usb/if_udav.c stable/7/sys/dev/usb/if_ural.c stable/7/sys/dev/usb/if_zyd.c stable/7/sys/dev/usb/udbp.c stable/7/sys/dev/vx/if_vx.c stable/7/sys/dev/wi/if_wi.c stable/7/sys/dev/wl/if_wl.c stable/7/sys/dev/wpi/if_wpi.c stable/7/sys/dev/xe/if_xe.c stable/7/sys/i4b/capi/capi_l4if.c stable/7/sys/i4b/driver/i4b_ing.c stable/7/sys/i4b/driver/i4b_isppp.c stable/7/sys/i4b/driver/i4b_trace.c stable/7/sys/i4b/layer1/ifpi/i4b_ifpi_pci.c stable/7/sys/i4b/layer1/ifpi2/i4b_ifpi2_pci.c stable/7/sys/i4b/layer1/ifpnp/i4b_ifpnp_avm.c stable/7/sys/i4b/layer1/ihfc/i4b_ihfc_drv.c stable/7/sys/i4b/layer1/isic/i4b_bchan.c stable/7/sys/i4b/layer1/itjc/i4b_itjc_pci.c stable/7/sys/i4b/layer1/iwic/i4b_iwic_bchan.c stable/7/sys/i4b/layer4/i4b_i4bdrv.c
Note that there is only yeterday's hardware in this list. The queue length should be per-interface and configured only by a sysctl, or better, drivers dynamically configure it to a good value. Bruce _______________________________________________ svn-src-all@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
