[PATCH net-next 10/10] hv_netvsc: remove locking in netvsc_send()

From: K. Y. Srinivasan
Date: Mon Nov 23 2015 - 16:58:55 EST


From: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

Packet scheduler guarantees there won't be multiple senders for the same
queue and as we use q_idx for multi_send_data the spinlock is redundant.

Signed-off-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>
Signed-off-by: K. Y. Srinivasan <kys@xxxxxxxxxxxxx>
---
drivers/net/hyperv/hyperv_net.h | 1 -
drivers/net/hyperv/netvsc.c | 8 --------
2 files changed, 0 insertions(+), 9 deletions(-)

diff --git a/drivers/net/hyperv/hyperv_net.h b/drivers/net/hyperv/hyperv_net.h
index a9d2bdc5..f5b2145 100644
--- a/drivers/net/hyperv/hyperv_net.h
+++ b/drivers/net/hyperv/hyperv_net.h
@@ -633,7 +633,6 @@ struct nvsp_message {
#define RNDIS_PKT_ALIGN_DEFAULT 8

struct multi_send_data {
- spinlock_t lock; /* protect struct multi_send_data */
struct hv_netvsc_packet *pkt; /* netvsc pkt pending */
u32 count; /* counter of batched packets */
};
diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index 419b055..081f14f 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -38,7 +38,6 @@ static struct netvsc_device *alloc_net_device(struct hv_device *device)
{
struct netvsc_device *net_device;
struct net_device *ndev = hv_get_drvdata(device);
- int i;

net_device = kzalloc(sizeof(struct netvsc_device), GFP_KERNEL);
if (!net_device)
@@ -58,9 +57,6 @@ static struct netvsc_device *alloc_net_device(struct hv_device *device)
net_device->max_pkt = RNDIS_MAX_PKT_DEFAULT;
net_device->pkt_align = RNDIS_PKT_ALIGN_DEFAULT;

- for (i = 0; i < num_online_cpus(); i++)
- spin_lock_init(&net_device->msd[i].lock);
-
hv_set_drvdata(device, net_device);
return net_device;
}
@@ -850,7 +846,6 @@ int netvsc_send(struct hv_device *device,
u16 q_idx = packet->q_idx;
u32 pktlen = packet->total_data_buflen, msd_len = 0;
unsigned int section_index = NETVSC_INVALID_INDEX;
- unsigned long flag;
struct multi_send_data *msdp;
struct hv_netvsc_packet *msd_send = NULL, *cur_send = NULL;
bool try_batch;
@@ -867,7 +862,6 @@ int netvsc_send(struct hv_device *device,
msdp = &net_device->msd[q_idx];

/* batch packets in send buffer if possible */
- spin_lock_irqsave(&msdp->lock, flag);
if (msdp->pkt)
msd_len = msdp->pkt->total_data_buflen;

@@ -927,8 +921,6 @@ int netvsc_send(struct hv_device *device,
cur_send = packet;
}

- spin_unlock_irqrestore(&msdp->lock, flag);
-
if (msd_send) {
m_ret = netvsc_send_pkt(msd_send, net_device);

--
1.7.4.1

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