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| author | Eric Dumazet <edumazet@google.com> | 2017-03-29 10:45:44 -0700 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-03-30 12:40:34 -0700 |
| commit | 142c6594acbcc32391af9c15f8cd65c6c177698f (patch) | |
| tree | c5f1c429b886d50480e7244d2275e18defa5de22 /drivers/net/bonding | |
| parent | ed8bfd5c1ca6e2911c797da611fdada958ab44c0 (diff) | |
| download | linux-142c6594acbcc32391af9c15f8cd65c6c177698f.tar.gz linux-142c6594acbcc32391af9c15f8cd65c6c177698f.tar.bz2 linux-142c6594acbcc32391af9c15f8cd65c6c177698f.zip | |
bonding: refine bond_fold_stats() wrap detection
Some device drivers reset their stats at down/up events, possibly
fooling bonding stats, since they operate with relative deltas.
It is nearly not possible to fix drivers, since some of them compute the
tx/rx counters based on per rx/tx queue stats, and the queues can be
reconfigured (ethtool -L) between the down/up sequence.
Lets avoid accumulating 'negative' values that render bonding stats
useless.
It is better to lose small deltas, assuming the bonding stats are
fetched at a reasonable frequency.
Fixes: 5f0c5f73e5ef ("bonding: make global bonding stats more reliable")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/bonding')
| -rw-r--r-- | drivers/net/bonding/bond_main.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index 6cea964ab70a..27359dab78a1 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -3332,12 +3332,17 @@ static void bond_fold_stats(struct rtnl_link_stats64 *_res, for (i = 0; i < sizeof(*_res) / sizeof(u64); i++) { u64 nv = new[i]; u64 ov = old[i]; + s64 delta = nv - ov; /* detects if this particular field is 32bit only */ if (((nv | ov) >> 32) == 0) - res[i] += (u32)nv - (u32)ov; - else - res[i] += nv - ov; + delta = (s64)(s32)((u32)nv - (u32)ov); + + /* filter anomalies, some drivers reset their stats + * at down/up events. + */ + if (delta > 0) + res[i] += delta; } } |