ofproto/bond: only display hash entries with tx_byptes > 1KB

When recirculation is used to implement bond, all bond entries are
always populated regardless whether there is traffic going through
them or not. This change cuts down the noise when running
'ovs-appctl bond/show', by skipping '0KB' entries.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
ofproto/bond: Keep hash entry slave valid.

Bond recirculation needs to refresh the 'hidden rules' from
time to time. Keep hash entry slave valid to prevent those
hidden rules from being removed.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
ofproto/bond: properly maintain hash entry pr_rule

This is a bug causing per hash entry's pr_rule pointer not properly
maintained; they became NULL after each rebalancing. This patch fixes
this bug.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
ofproto-dpif: xlate should not attribute stats to bond entry when using recirc

When recirculation is used to implement bond, the bond entry stats are
collected from the hidden post recirculation rules. This bug causes
double counting of stats to some strenuous bond entries.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Jarno Rajahalme <jrajahalme@nicira.com>
datapath: Fix a double free bug for the sample action

When sample action returns with an error, the skb has already been
freed. This patch fix a bug to make sure we don't free it again.
dpif-netdev: Move hash function out of the recirc action, into its own action

Currently recirculation action can optionally compute hash. This patch
adds a hash action that is independent of the recirc action, which
no longer computes hash.  For megaflow bond with recirc, the output
to a bond port action will look like:

    hash(hash_l4(0)), recirc(<recirc_id>)

Obviously, when a recirculation application that does not depend on
hash value can just use the recirc action alone.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Reviewed-by: YAMAMOTO Takashi <yamamoto@valinux.co.jp>
Acked-by: Pravin B Shelar <pshelar@nicira.com
ofproto: New function ofproto_refresh_rule().

This function checks for a rule in the classifier:
* If the rule exists, reset its modified time.
* If an equivalent rule exists, reset that rule's modified time.
* If no rule exists, re-install the rule and reset its modified time.
* Finally, return the rule that was modified.

This function will be used to ensure that hard timeouts for learnt rules
are refreshed if traffic consistently hits a rule with a learn action in
it. The first user will be the next commit.

Signed-off-by: Joe Stringer <joestringer@nicira.com>
Acked-by: Ethan Jackson <ethan@nicira.com>
---
v1: Ensure rule->modified is updated correctly.
RFC: First post.
ofproto-dpif-xlate: Cache xlate_actions() effects.

This patch adds a new object called 'struct xlate_cache' which can be
set in 'struct xlate_in', and passed to xlate_actions() to cache the
modules affected by this flow translation. Subsequently, the caller can
pass the xcache to xlate_push_stats() to credit stats and perform side
effects for a lower cost than full flow translation.

These changes are aimed currently at long-lived flows, decreasing the
average dump duration for such flows by 50-80%. This allows more flows
to be supported in the datapath at a given time. Applying these changes
to short-lived flows is left for a later commit.

Signed-off-by: Joe Stringer <joestringer@nicira.com>
---
v1: Add caching for fin_timeout action.
    Expire netflows on xlate_cache_clear().
    Account to bonds using a copy of 'flow' rather than hash.
    Always build XC_NORMAL entry (previously only if may_learn is true)
    Rename xlate_from_cache()->xlate_push_stats()
    Add may_learn parameter to xlate_push_stats()
    Tidy up xlate_actions__() mirror/netflow code.
    Fold in style fixups.
RFC: First post.
revalidator: Only revalidate high-throughput flows.

Previously we would revalidate all flows if the "need_revalidate" flag
was raised. This patch modifies the logic to delete low throughput flows
rather than revalidate them. High-throughput flows are unaffected by
this change. This patch identifies the flows based on the mean time
between packets since the last dump.

This change is primarily targeted at situations where:
* Flow dump duration is high (~1 second)
* Revalidation is triggered. (eg, by bridge reconfiguration or learning)

After the need_revalidate flag is set, next time a new flow dump session
starts, revalidators will begin revalidating the flows. This full
revalidation is more expensive, which significantly increases the flow
dump duration. At the end of this dump session, the datapath flow
management algorithms kick in for the next dump:

* If flow dump duration becomes too long, the flow limit is decreased.
* The number of flows in the datapath then exceeds the flow_limit.
* As the flow_limit is exceeded, max_idle is temporarily set to 100ms.
* Revalidators delete all flows that haven't seen traffic recently.

The effect of this is that many low-throughput flows are deleted after
revalidation, even if they are valid. The revalidation is unnecessary
for flows that would be deleted anyway, so this patch skips the
revalidation step for those flows.

Note that this patch will only perform this optimization if the flow has
already been dumped at least once, and only if the time since the last
dump is sufficiently long. This gives the flow a chance to become
high-throughput.

Signed-off-by: Joe Stringer <joestringer@nicira.com>
---
v1: Determine "high-throughput" by packets rather than bytes.
    Calculate the mean time between packets for comparison, rather than
      comparing the number of packets since the last dump.
RFC: First post.