On Wed, May 02, 2007 at 03:38:53AM -0400, Jeff Garzik wrote: > David Miller wrote: > >From: Jeff Garzik <[EMAIL PROTECTED]> > >Date: Wed, 02 May 2007 03:17:20 -0400 > > > >>Michael Chan wrote: > >>>[BNX2]: Enhance the heartbeat. > >>> > >>>In addition to the periodic heartbeat, we're adding a heartbeat > >>>request interrupt when the heartbeat is late. This is useful > >>>especially in -rt kernels where the timer frequently runs late. > >>> > >>>Signed-off-by: Michael Chan <[EMAIL PROTECTED]> > >>Should we really be adding code for such a special situation to upstream > >>code? > >> > >>I lean towards "no", but defer to your and DaveM's judgement here. > > > >My understanding of this situation is that if the timer is delayed a > >lot, which can happen with the -rt kernel, we don't send the heartbeat > >ping to the chip within the required margin. > > > >If the margin is not met, the ASF firmware takes this as a signal that > >the host system is down, and does things like reset the network card > >and other things we don't want it to do. > > Thanks for the explanation. > > My main concern was > > * adding code to use a kernel facility > * then, adding code to handle when that kernel facility doesn't work > > and also > > * adding code for a situation that never occurs in the upstream kernel.
Yeah, we shouldn't add this. If the rt kernel can't deliver low latency real time guarantees to the hardware it's pretty buggy :) - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
