Hi Neale,
I ran perf output and here are the top contenders (no suspects):
http://pasteboard.co/2yxUamC1f.png
-nagp
On Mon, Apr 10, 2017 at 2:52 PM, Neale Ranns (nranns) <nra...@cisco.com>
wrote:
>
>
> Hi nagp,
>
>
>
> From your ‘sh fib walk’ output we can see:
>
>
>
> 1. DBGvpp# show fib walk
>
> 2. …
>
> 3. Sleep Types:
>
> 4. Short Long:
>
> 5. 0 717658:
>
>
>
> indicating the process is sleeping for its “long” period:
>
>
>
> /**
>
> * @brief Durations for the sleep types [in seconds]
>
> */
>
> static f64 fib_walk_sleep_duration[] = {
>
> [FIB_WALK_LONG_SLEEP] = 1e-3,
>
> [FIB_WALK_SHORT_SLEEP] = 1e-8,
>
> };
>
>
>
> I’d suggest ‘[sudo] perf top’ as a means to determine what is consuming
> the CPU time.
>
>
>
> Regards,
>
> neale
>
>
>
>
>
> *From: *Nagaprabhanjan Bellaru <nagp.li...@gmail.com>
> *Date: *Monday, 10 April 2017 at 09:53
> *To: *"Neale Ranns (nranns)" <nra...@cisco.com>
> *Cc: *vpp-dev <vpp-dev@lists.fd.io>
> *Subject: *Re: [vpp-dev] fib-walk is consuming 100% CPU..
>
>
>
> Thanks Neale!!
>
> I don't see any loops in the routes in the fib. In fact, as soon as vpp
> starts, I see the CPU going to 100%.
>
> The output of "sh fib walk" is at: https://pastebin.com/G9YEkVGc
>
> The output of "sh run" is at: https://pastebin.com/RYtF9fHM
>
> "sh run" shows number of suspends as high, possibly because of a short
> sleep duration?
>
>
>
>
>
> On Mon, Apr 10, 2017 at 2:04 PM, Neale Ranns (nranns) <nra...@cisco.com>
> wrote:
>
> Hi nagp,
>
>
>
> A FIB walk that consumes 100% CPU is usually indicative of a cycle/loop in
> the FIB undirected graph. Cycles in routing should not form permanently,
> i.e. the routing protocols will eventually converge away from the loop, but
> they can form temporarily.
>
> Use;
>
> ‘sh fib walk’
>
> to see the objects/nodes in the graph that are being visited in the walk.
> This will give you output like:
>
>
>
> Brief History (last 128 walks):
>
> …
>
> [@6]: path-list:12 visits:1 duration:0.00 completed:85.06 sync,
> reason:evaluate,
>
> …
>
>
>
> you can then see in detail with;
>
> ‘sb fib <TYPE> <INSTANCE>’
>
> e.g.
>
> ‘sh fib path-list 12’
>
> ‘sh fib entry 19’
>
>
>
> if no cycle exists let me know. If one does exist, please debug from the
> from a routing perspective.
>
>
>
> Regards,
>
> /neale
>
>
>
> *From: *<vpp-dev-boun...@lists.fd.io> on behalf of Nagaprabhanjan Bellaru
> <nagp.li...@gmail.com>
> *Date: *Monday, 10 April 2017 at 09:04
> *To: *vpp-dev <vpp-dev@lists.fd.io>
> *Subject: *[vpp-dev] fib-walk is consuming 100% CPU..
>
>
>
> There are a few routes in FIB, but fib-walk takes up 100% CPU. "show run"
> shows fib-wak process running perpetually.
>
> Is there anything that we can do to get around this?
>
> Thanks,
>
> -nagp
>
>
>
>
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