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| author |   Eric Dumazet <edumazet@google.com> | 2019-10-09 09:20:02 -0700 |
|---|---|---|
| committer |   Jakub Kicinski <jakub.kicinski@netronome.com> | 2019-10-09 21:29:33 -0700 |
| commit | 4ffdd22e49f47db543906d75453a0048a53071ab (patch) | |
| tree | 3fe252f49f9e7e4997a70c124594f6b459ee709b /net/core/sock.c | |
| parent | netfilter: conntrack: avoid possible false sharing (diff) | |
| download | linux-dev-4ffdd22e49f47db543906d75453a0048a53071ab.tar.xz linux-dev-4ffdd22e49f47db543906d75453a0048a53071ab.zip | |
tun: remove possible false sharing in tun_flow_update()
As mentioned in https://github.com/google/ktsan/wiki/READ_ONCE-and-WRITE_ONCE#it-may-improve-performance
a C compiler can legally transform
if (e->queue_index != queue_index)
e->queue_index = queue_index;
to :
e->queue_index = queue_index;
Note that the code using jiffies has no issue, since jiffies
has volatile attribute.
if (e->updated != jiffies)
e->updated = jiffies;
Fixes: 83b1bc122cab ("tun: align write-heavy flow entry members to a cache line")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Zhang Yu <zhangyu31@baidu.com>
Cc: Wang Li <wangli39@baidu.com>
Cc: Li RongQing <lirongqing@baidu.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Diffstat (limited to 'net/core/sock.c')
0 files changed, 0 insertions, 0 deletions