Re: [PATCH net-next 3/4] hv_netvsc: reset net_device_ctx->nvdev with rcu_assign_pointer()
From: Eric Dumazet <hidden>
Date: 2017-10-31 14:10:02
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On Tue, 2017-10-31 at 14:42 +0100, Vitaly Kuznetsov wrote:
quoted hunk ↗ jump to hunk
RCU_INIT_POINTER() is not suitable here as it doesn't give us ordering guarantees (see the comment in rcupdate.h). This is also not a hotpath. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> --- drivers/net/hyperv/netvsc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index bfc79698b8f4..12efb3e34775 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c@@ -560,7 +560,7 @@ void netvsc_device_remove(struct hv_device *device) netvsc_revoke_buf(device, net_device); - RCU_INIT_POINTER(net_device_ctx->nvdev, NULL); + rcu_assign_pointer(net_device_ctx->nvdev, NULL);
I see no point for this patch. Setting a NULL pointer needs no barrier at all.