On Wed, Feb 28, 2018 at 2:14 PM, Ben Pfaff <[email protected]> wrote: > On Mon, Feb 26, 2018 at 01:43:39PM -0800, William Tu wrote: >> On Wed, Feb 14, 2018 at 3:03 PM, Ben Pfaff <[email protected]> wrote: >> > On Wed, Feb 14, 2018 at 10:56:08AM -0800, William Tu wrote: >> >> Usually ofproto/trace is used to debug the flow translation error. >> >> When translation error such as recursion too deep or too many resubmit, >> >> the issue might happen momentary; flows causing the recursion expire >> >> when users try to debug it. This patch enables the ofproto trace >> >> automatically when recursion is too deep or too many resubmit, by >> >> invoking the translation again, and log the ofproto trace as warnings. >> >> Since the log will be huge, rate limit to one per minute. >> >> >> >> VMWare-BZ: #2054659 >> >> Signed-off-by: William Tu <[email protected]> >> >> Tested-by: Greg Rose <[email protected]> >> >> Reviewed-by: Greg Rose <[email protected]> >> > >> > Thanks for working on this! >> > >> > Some of the data passed to ofproto_trace() is also passed to the >> > xlate_actions() call, indirectly. Did you check whether that data is >> > possibly modified by xlate_actions()? If it is, then we might have to >> > reconsider this approach, because flow data, etc. is very large and I >> > don't think that we can afford to always make a copy of it in advance on >> > the chance that the original might be needed for tracing later. >> >> We pass the "const struct flow *" and "const struct dp_packet *" to >> the ofproto_trace(), >> so I think these two data is unmodified and xlate_in_init() actually make a >> copy >> of the "struct flow", so xlate_actions() modifies a separate copy of the >> flow. > > OK. > >> > I think that VLOG_WARN is a very high log level for this data. I would >> > tend to use DBG. >> > >> I worried that most of the time DBG is not on, and asking people >> to turn it on and reproduce the issue is hard. Can we keep VLOG_WARN and >> rate limit to very low frequent, "VLOG_RATE_LIMIT_INIT(1, 5);",? > > OK, let's try that.
Thanks Ben. Should I send another version of the patch? William _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
