From: Antoine Tenart <atenart@kernel.org>
To: davem@davemloft.net, kuba@kernel.org, alexander.duyck@gmail.com
Cc: Antoine Tenart <atenart@kernel.org>, netdev@vger.kernel.org
Subject: [PATCH net-next v2 09/12] net-sysfs: remove the rtnl lock when accessing the xps maps
Date: Mon, 8 Feb 2021 18:19:14 +0100 [thread overview]
Message-ID: <20210208171917.1088230-10-atenart@kernel.org> (raw)
In-Reply-To: <20210208171917.1088230-1-atenart@kernel.org>
Now that nr_ids and num_tc are stored in the xps dev_maps, which are RCU
protected, we do not have the need to protect the xps_cpus_show and
xps_rxqs_show functions with the rtnl lock.
Signed-off-by: Antoine Tenart <atenart@kernel.org>
---
net/core/net-sysfs.c | 26 ++++----------------------
1 file changed, 4 insertions(+), 22 deletions(-)
diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c
index c2276b589cfb..6ce5772e799e 100644
--- a/net/core/net-sysfs.c
+++ b/net/core/net-sysfs.c
@@ -1328,17 +1328,12 @@ static ssize_t xps_cpus_show(struct netdev_queue *queue,
index = get_netdev_queue_index(queue);
- if (!rtnl_trylock())
- return restart_syscall();
-
/* If queue belongs to subordinate dev use its map */
dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
tc = netdev_txq_to_tc(dev, index);
- if (tc < 0) {
- ret = -EINVAL;
- goto err_rtnl_unlock;
- }
+ if (tc < 0)
+ return -EINVAL;
rcu_read_lock();
dev_maps = rcu_dereference(dev->xps_maps[XPS_CPUS]);
@@ -1371,16 +1366,12 @@ static ssize_t xps_cpus_show(struct netdev_queue *queue,
out_no_maps:
rcu_read_unlock();
- rtnl_unlock();
-
len = bitmap_print_to_pagebuf(false, buf, mask, nr_ids);
bitmap_free(mask);
return len < PAGE_SIZE ? len : -EINVAL;
err_rcu_unlock:
rcu_read_unlock();
-err_rtnl_unlock:
- rtnl_unlock();
return ret;
}
@@ -1435,14 +1426,9 @@ static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf)
index = get_netdev_queue_index(queue);
- if (!rtnl_trylock())
- return restart_syscall();
-
tc = netdev_txq_to_tc(dev, index);
- if (tc < 0) {
- ret = -EINVAL;
- goto err_rtnl_unlock;
- }
+ if (tc < 0)
+ return -EINVAL;
rcu_read_lock();
dev_maps = rcu_dereference(dev->xps_maps[XPS_RXQS]);
@@ -1475,8 +1461,6 @@ static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf)
out_no_maps:
rcu_read_unlock();
- rtnl_unlock();
-
len = bitmap_print_to_pagebuf(false, buf, mask, nr_ids);
bitmap_free(mask);
@@ -1484,8 +1468,6 @@ static ssize_t xps_rxqs_show(struct netdev_queue *queue, char *buf)
err_rcu_unlock:
rcu_read_unlock();
-err_rtnl_unlock:
- rtnl_unlock();
return ret;
}
--
2.29.2
next prev parent reply other threads:[~2021-02-08 17:24 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-08 17:19 [PATCH net-next v2 00/12] net: xps: improve the xps maps handling Antoine Tenart
2021-02-08 17:19 ` [PATCH net-next v2 01/12] net-sysfs: convert xps_cpus_show to bitmap_zalloc Antoine Tenart
2021-02-08 17:19 ` [PATCH net-next v2 02/12] net-sysfs: store the return of get_netdev_queue_index in an unsigned int Antoine Tenart
2021-02-08 17:19 ` [PATCH net-next v2 03/12] net-sysfs: make xps_cpus_show and xps_rxqs_show consistent Antoine Tenart
2021-02-08 17:19 ` [PATCH net-next v2 04/12] net: embed num_tc in the xps maps Antoine Tenart
2021-02-08 17:19 ` [PATCH net-next v2 05/12] net: embed nr_ids " Antoine Tenart
2021-02-08 17:19 ` [PATCH net-next v2 06/12] net: assert the rtnl lock is held when calling __netif_set_xps_queue Antoine Tenart
2021-02-23 6:27 ` [net] 81bb8ff453: assertion_failed kernel test robot
2021-02-08 17:19 ` [PATCH net-next v2 07/12] net: remove the xps possible_mask Antoine Tenart
2021-02-08 21:43 ` Alexander Duyck
2021-02-09 8:47 ` Antoine Tenart
2021-02-08 17:19 ` [PATCH net-next v2 08/12] net: move the xps maps to an array Antoine Tenart
2021-02-08 17:19 ` Antoine Tenart [this message]
2021-02-08 22:20 ` [PATCH net-next v2 09/12] net-sysfs: remove the rtnl lock when accessing the xps maps Alexander Duyck
2021-02-09 9:12 ` Antoine Tenart
2021-02-09 9:20 ` Antoine Tenart
2021-02-08 17:19 ` [PATCH net-next v2 10/12] net: add an helper to copy xps maps to the new dev_maps Antoine Tenart
2021-02-08 17:19 ` [PATCH net-next v2 11/12] net: improve queue removal readability in __netif_set_xps_queue Antoine Tenart
2021-02-08 17:19 ` [PATCH net-next v2 12/12] net-sysfs: move the xps cpus/rxqs retrieval in a common function Antoine Tenart
2021-02-08 22:45 ` Alexander Duyck
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