From: Stephen Hemminger <stephen@networkplumber.org>
To: Saeed Mahameed <saeedm@mellanox.com>
Cc: "David S. Miller" <davem@davemloft.net>,
netdev@vger.kernel.org, Gal Pressman <galp@mellanox.com>,
kernel-team@fb.com
Subject: Re: [net 1/6] net/mlx5e: Use a spinlock to synchronize statistics
Date: Mon, 15 May 2017 15:51:19 -0700 [thread overview]
Message-ID: <20170515155119.040047d1@xeon-e3> (raw)
In-Reply-To: <20170512115650.11635-2-saeedm@mellanox.com>
On Fri, 12 May 2017 14:56:45 +0300
Saeed Mahameed <saeedm@mellanox.com> wrote:
> diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en.h b/drivers/net/ethernet/mellanox/mlx5/core/en.h
> index 0099a3e397bc..c41cf7e82795 100644
> --- a/drivers/net/ethernet/mellanox/mlx5/core/en.h
> +++ b/drivers/net/ethernet/mellanox/mlx5/core/en.h
> @@ -756,6 +756,7 @@ struct mlx5e_priv {
> struct mlx5_core_dev *mdev;
> struct net_device *netdev;
> struct mlx5e_stats stats;
> + rwlock_t stats_lock;
A reader-writer lock is slower than a spin_lock.
The only case where reader/writer lock is preferred is when writer
will hold onto the lock for a significant amount of time.
Also you only need each statistic to be atomic, the network device API
never guarantees transactional update across multiple statistics.
next prev parent reply other threads:[~2017-05-15 22:51 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-05-12 11:56 [pull request][net 0/6] Mellanox, mlx5 fixes 2017-05-12 Saeed Mahameed
2017-05-12 11:56 ` [net 1/6] net/mlx5e: Use a spinlock to synchronize statistics Saeed Mahameed
2017-05-12 16:13 ` David Miller
2017-05-14 8:52 ` Saeed Mahameed
2017-05-15 18:39 ` David Miller
2017-05-15 22:51 ` Stephen Hemminger [this message]
2017-05-12 11:56 ` [net 2/6] net/mlx5e: Use the correct pause values for ethtool advertising Saeed Mahameed
2017-05-12 11:56 ` [net 3/6] net/mlx5e: Fix ethtool pause support and advertise reporting Saeed Mahameed
2017-05-12 11:56 ` [net 4/6] net/mlx5e: Fix setup TC ndo Saeed Mahameed
2017-05-12 11:56 ` [net 5/6] net/mlx5e: IPoIB, Only support regular RQ for now Saeed Mahameed
2017-05-12 11:56 ` [net 6/6] net/mlx5: Use underlay QPN from the root name space Saeed Mahameed
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