Messages in this thread | | | Subject | Re: [PATCH v2 net 5/6] net: mvneta: The mvneta_percpu_elect function should be atomic | From | Sergei Shtylyov <> | Date | Mon, 1 Feb 2016 16:33:44 +0300 |
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On 2/1/2016 4:07 PM, Gregory CLEMENT wrote:
> 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 <gregory.clement@free-electrons.com> > --- > 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 [...] > @@ -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
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