sco...@freebsd.org Bcc: Subject: Full 32bit flowid from igb(4) [was: Re: Unbalanced LACP link] Reply-To: In-Reply-To: <20150319175145.gh53...@strugglingcoder.info>
On 03/19/15 at 10:51P, hiren panchasara wrote: > On 03/17/15 at 12:34P, Adrian Chadd wrote: > > On 17 March 2015 at 11:33, Jason Wolfe <nitrobo...@gmail.com> wrote: > > > On Mon, Mar 16, 2015 at 2:43 AM, Hans Petter Selasky <h...@selasky.org> > > > wrote: > > >> On 03/16/15 10:37, Vitalii Duk wrote: > > >>> > > >>> I've changed use_flowid to 0 and it helped! But isn't it setting > > >>> significant? In a description it says "Shift flowid bits to prevent > > >>> multiqueue collisions". > > >> > > >> > > >> Hi, > > >> > > >> Maybe your ethernet hardware is not properly setting the m_flowid ... > > >> > > >> --HPS > > >> > > > > > > Flip use_flowid back to 1 and try setting > > > net.link.lagg.default_flowid_shift / net.link.lagg.X.flowid_shift to 0 > > > as Hiren suggested. r260179 added this shift, which has caused us > > > balancing issues with the i350/igb. > > > > > > https://svnweb.freebsd.org/base?view=revision&revision=260179 > > > > > > Based on Adrian's comment about igb/ixgbe not setting the 'full > > > flowid' under normal conditions, does that mean this shift should be 0 > > > by default to ensure we don't break balancing for devices that only > > > set the CPU/MSIX queue? > > > > Or we can just see if there's anything wrong with putting the full 32 > > bit RSS flowid in received packets that have them. > > It'd be nice to have but for now I am proposing following to fix a known > broken case because of an optimization: > https://reviews.freebsd.org/D2098 Turns out, setting flowid_shift to 0 is not the correct solution. Please look at the review above for more details. Looking at the code, we have a way to get full flowid but it's hidden under "ifdef RSS": rxr->fmp->m_pkthdr.flowid = le32toh(cur->wb.lower.hi_dword.rss); Using just this line gives me good hash on I350 igb(4) chipset that we have. Is it possible to expose this outside RSS? Would this break other things/chips? Cheers, Hiren
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