Eric Dumazet 910699a81f net: avoid possible false sharing in sk_leave_memory_pressure() ...

[ Upstream commit 503978aca4 ]

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 (memory_pressure && *memory_pressure)
        *memory_pressure = 0;

to :

if (memory_pressure)
        *memory_pressure = 0;

Fixes: 0604475119 ("tcp: add TCPMemoryPressuresChrono counter")
Fixes: 180d8cd942 ("foundations of per-cgroup memory pressure controlling.")
Fixes: 3ab224be6d ("[NET] CORE: Introducing new memory accounting interface.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

2020-01-27 14:51:18 +01:00

83 KiB

Raw Blame History

View Raw