[PATCH v2 net 5/6] net: mvneta: The mvneta_percpu_elect function should be atomic
From: Sergei Shtylyov <hidden>
Date: 2016-02-01 13:33:50
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lkml, netdev
On 2/1/2016 4:07 PM, Gregory CLEMENT wrote:
quoted hunk ↗ jump to hunk
Electing a CPU must be done in an atomic way: it should be done after or before the removal/insertion of a CPU and this function is not reentrant. During the loop of mvneta_percpu_elect we associates the queues to the CPUs, if there is a topology change during this loop, then the mapping between the CPUs and the queues could be wrong. During this loop the interrupt mask is also updating for each CPUs, It should not be changed in the same time by other part of the driver. This patch adds spinlock to create the needed critical sections. Signed-off-by: Gregory CLEMENT <redacted> --- drivers/net/ethernet/marvell/mvneta.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+)diff --git a/drivers/net/ethernet/marvell/mvneta.c b/drivers/net/ethernet/marvell/mvneta.c index 1ed813d478e8..4d40d2fde7ca 100644 --- a/drivers/net/ethernet/marvell/mvneta.c +++ b/drivers/net/ethernet/marvell/mvneta.c
[...]
quoted hunk ↗ jump to hunk
@@ -2855,6 +2859,11 @@ static void mvneta_percpu_elect(struct mvneta_port *pp) { int online_cpu_idx, max_cpu, cpu, i = 0; + /* Electing a CPU must done in an atomic way: it should be
Must be done.
+ * done after or before the removal/insertion of a CPU and + * this function is not reentrant. + */ + spin_lock(&pp->lock); online_cpu_idx = pp->rxq_def % num_online_cpus(); max_cpu = num_present_cpus();
[...] MBR, Sergei