diff options
| author | Eric Dumazet <edumazet@google.com> | 2017-03-29 10:45:44 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-22 09:17:45 +0100 |
| commit | 8c989a6803e4e235cd50d789a7ebe6fad10f747d (patch) | |
| tree | 1cbdf342292c9a464ea04e7e8c7fa33ce0cccd17 /drivers/net/bonding | |
| parent | 508126005146f7a8d0c44c2acd02f0fce1665ccd (diff) | |
bonding: refine bond_fold_stats() wrap detection
[ Upstream commit 142c6594acbcc32391af9c15f8cd65c6c177698f ]
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>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 6b4b43319ffa..c3f3096b24ae 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -3331,12 +3331,17 @@ 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; } } |