diff options
| author | Eric Dumazet <edumazet@google.com> | 2022-02-25 08:18:55 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2022-02-28 11:40:47 +0000 |
| commit | b3483bc7a1f2673b35331e60668104ba2be46510 (patch) | |
| tree | 2d43f17047844c6ce22ece7d96ff6e085061dc81 /net/core/sysctl_net_core.c | |
| parent | 6a4696c4284f758e8418e5507c3c757ecdf262a4 (diff) | |
| download | lwn-b3483bc7a1f2673b35331e60668104ba2be46510.tar.gz lwn-b3483bc7a1f2673b35331e60668104ba2be46510.zip | |
net/sysctl: avoid two synchronize_rcu() calls
Both rps_sock_flow_sysctl() and flow_limit_cpu_sysctl()
are using synchronize_rcu() right before freeing memory
either by vfree() or kfree()
They can switch to kvfree_rcu(ptr) and kfree_rcu(ptr) to benefit
from asynchronous mode, instead of blocking the current thread.
Note that kvfree_rcu(ptr) and kfree_rcu(ptr) eventually can
have to use synchronize_rcu() in some memory pressure cases.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/sysctl_net_core.c')
| -rw-r--r-- | net/core/sysctl_net_core.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c index dbeb8ecbcd98..7123fe7feeac 100644 --- a/net/core/sysctl_net_core.c +++ b/net/core/sysctl_net_core.c @@ -103,8 +103,7 @@ static int rps_sock_flow_sysctl(struct ctl_table *table, int write, if (orig_sock_table) { static_branch_dec(&rps_needed); static_branch_dec(&rfs_needed); - synchronize_rcu(); - vfree(orig_sock_table); + kvfree_rcu(orig_sock_table); } } } @@ -142,8 +141,7 @@ static int flow_limit_cpu_sysctl(struct ctl_table *table, int write, lockdep_is_held(&flow_limit_update_mutex)); if (cur && !cpumask_test_cpu(i, mask)) { RCU_INIT_POINTER(sd->flow_limit, NULL); - synchronize_rcu(); - kfree(cur); + kfree_rcu(cur); } else if (!cur && cpumask_test_cpu(i, mask)) { cur = kzalloc_node(len, GFP_KERNEL, cpu_to_node(i)); |