You have to overrun the fifo on the hardware to see rx_dropped error from hardware. Currently your cpu is fast enough to keep up with the packet load.
On Wed, May 25, 2011 at 7:32 PM, Filo FeFi <j11...@yahoo.com> wrote: > Ah! > > I've been looking for it in kernel version 2.6.18 which doesn't seem > to have the function. I should have mentioned it. > > In my test, I'm send many packets to the ixgbe: > kernel 2.6.18 > ixgbe 3.3.9 w/o NAPI > > I'm seeing ixgbe's call to netif_rx() returning NET_RX_DROP, and it is > incrementing adapter->rx_dropped_backlog. However, this value isn't > reported by ifconfig's rx dropped. > > I can see ixgbe_ethtool.c sends it to ethtool, so I can use that; also, > as per Eric Dumazet's earlier email, I see that /proc/net/softnet_stat > drop count being incremented in the netif_rx() function. > > But so far, I keep seeing "0" in ifconfig's RX dropped. I'm wondering > under what situation can I see something other than "0". > > Thanks, > Ching > > > --- On Wed, 5/25/11, Alexander Duyck <alexander.h.du...@intel.com> wrote: > >> From: Alexander Duyck <alexander.h.du...@intel.com> >> Subject: Re: [E1000-devel] Question on net_stats->rx_dropped setting to "0" >> To: "Filo FeFi" <j11...@yahoo.com> >> Cc: "e1000-devel@lists.sourceforge.net" <e1000-devel@lists.sourceforge.net>, >> "Skidmore, Donald C" <donald.c.skidm...@intel.com> >> Date: Wednesday, May 25, 2011, 11:57 AM >> The function should be around line >> 1500 in /net/core/dev.c of the Linux >> kernel. I've included a link to it in lxr below. >> >> http://lxr.linux.no/#linux+v2.6.39/net/core/dev.c#L1498 >> >> Thanks, >> >> Alex >> >> On 05/25/2011 02:41 PM, Filo FeFi wrote: >> > Hi Don, >> > >> > Could you please elaborate a little on the >> dev_forward_skb() ? >> > Where can I find that function? >> > >> > I was about to conclude that ixgbe always report "0" >> for RX drop, >> > but I would like to know the correct answer. >> > >> > Thanks, >> > Ching >> > >> > --- On Mon, 5/23/11, Skidmore, Donald C<donald.c.skidm...@intel.com> >> wrote: >> > >> >> From: Skidmore, Donald C<donald.c.skidm...@intel.com> >> >> Subject: RE: [E1000-devel] Question on >> net_stats->rx_dropped setting to "0" >> >> To: "Filo FeFi"<j11...@yahoo.com>, >> "e1000-devel@lists.sourceforge.net"<e1000-devel@lists.sourceforge.net> >> >> Date: Monday, May 23, 2011, 5:55 PM >> >> Hi Ching, >> >> >> >> As you noted we (ixgbe) doesn't modify this value, >> other >> >> than initialing it to zero. However >> elsewhere in the >> >> stack it is modified. One example being >> dev_forward_skb(). >> >> So ixgbe devices may report rx_dropped as >> something other >> >> than "0". >> >> >> >> Thanks, >> >> -Don >> >> >> >>> -----Original Message----- >> >>> From: Filo FeFi [mailto:j11...@yahoo.com] >> >>> Sent: Thursday, May 19, 2011 7:19 PM >> >>> To: e1000-devel@lists.sourceforge.net >> >>> Subject: [E1000-devel] Question on >> >> net_stats->rx_dropped setting to "0" >> >>> Dear ixgbe developers: >> >>> >> >>> I'm debugging a problem where some frames get >> dropped >> >> by the ixgbe >> >>> driver (version 2.0.44-k2), i.e. /proc/net/dev >> "drop" >> >> is not 0. >> >>> Reading the ixgbe-3.3.9/2.0.44.13/2.0.44.14 >> source, I >> >> see the line >> >>> (in ixgbe_main.c ixgbe_update_stats()): >> >> "net_stats->rx_dropped = 0;" >> >>> So, does this mean that ixgbe always reports >> "0" for RX >> >> dropped? >> >>> Under what circumstances would /proc/net/dev's >> drop >> >> count for ixgbe >> >>> be incremented/changed from "0"? >> >>> >> >>> Thank you, >> >>> Ching Tai >> >>> (650) 506-1454 >> >>> >> >>> >> >>> >> ------------------------------------------------------------------------ >> >>> ------ >> >>> What Every C/C++ and Fortran developer Should >> Know! >> >>> Read this article and learn how Intel has >> extended the >> >> reach of its >> >>> next-generation tools to help Windows* and >> Linux* C/C++ >> >> and Fortran >> >>> developers boost performance applications - >> including >> >> clusters. >> >>> http://p.sf.net/sfu/intel-dev2devmay >> >>> >> _______________________________________________ >> >>> E1000-devel mailing list >> >>> E1000-devel@lists.sourceforge.net >> >>> https://lists.sourceforge.net/lists/listinfo/e1000-devel >> >>> To learn more about Intel® Ethernet, visit >> >>> http://communities.intel.com/community/wired >> > >> ------------------------------------------------------------------------------ >> > vRanger cuts backup time in half-while increasing >> security. >> > With the market-leading solution for virtual backup >> and recovery, >> > you get blazing-fast, flexible, and affordable data >> protection. >> > Download your free trial now. >> > http://p.sf.net/sfu/quest-d2dcopy1 >> > _______________________________________________ >> > E1000-devel mailing list >> > E1000-devel@lists.sourceforge.net >> > https://lists.sourceforge.net/lists/listinfo/e1000-devel >> > To learn more about Intel® Ethernet, visit >> > http://communities.intel.com/community/wired >> >> > > ------------------------------------------------------------------------------ > vRanger cuts backup time in half-while increasing security. > With the market-leading solution for virtual backup and recovery, > you get blazing-fast, flexible, and affordable data protection. > Download your free trial now. > http://p.sf.net/sfu/quest-d2dcopy1 > _______________________________________________ > E1000-devel mailing list > E1000-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/e1000-devel > To learn more about Intel® Ethernet, visit > http://communities.intel.com/community/wired > ------------------------------------------------------------------------------ vRanger cuts backup time in half-while increasing security. 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