[dpdk-dev] net/failsafe: fix Rx interrupt reinstallation
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Commit Message
Hi Matan,
On Tue, Feb 13, 2018 at 10:59:32PM +0000, Matan Azrad wrote:
> Fail-safe dev_start() operation can be called by both the application
> and the hot-plug alarm mechanism.
>
> The installation of Rx interrupt are triggered from dev_start() in any
> time it is called while actually the Rx interrupt should be installed
> only by the application calls.
>
> So, each plug-in event causes reinstallation which causes memory leak.
>
> Trigger the Rx interrupt installation only for application calls.
>
> Fixes: 9e0360aebf23 ("net/failsafe: register as Rx interrupt mode")
>
> Signed-off-by: Matan Azrad <matan@mellanox.com>
> ---
> drivers/net/failsafe/failsafe_ops.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/net/failsafe/failsafe_ops.c b/drivers/net/failsafe/failsafe_ops.c
> index 057e435..bbbd335 100644
> --- a/drivers/net/failsafe/failsafe_ops.c
> +++ b/drivers/net/failsafe/failsafe_ops.c
> @@ -181,10 +181,12 @@
> int ret;
>
> fs_lock(dev, 0);
> - ret = failsafe_rx_intr_install(dev);
> - if (ret) {
> - fs_unlock(dev, 0);
> - return ret;
> + if (PRIV(dev)->alarm_lock == 0) {
I dislike having to rely on unrelated context of execution to decide a
code-path.
I'd prefer to make interrupt installation dependent on the interrupt
state instead.
I think it should be possible to forbid reinstallation within
failsafe_rx_intr_install directly, e.g.
This way the logic is self-dependent and the check limited to this
component.
There might be better way to do this, it's only an example to explain my
point.
> + ret = failsafe_rx_intr_install(dev);
> + if (ret) {
> + fs_unlock(dev, 0);
> + return ret;
> + }
> }
> FOREACH_SUBDEV(sdev, i, dev) {
> if (sdev->state != DEV_ACTIVE)
> --
> 1.9.5
>
Comments
Hi Gaetan
Agree, will send V2.
> -----Original Message-----
> From: Gaëtan Rivet [mailto:gaetan.rivet@6wind.com]
> Sent: Wednesday, February 14, 2018 3:52 PM
> To: Matan Azrad <matan@mellanox.com>
> Cc: dev@dpdk.org
> Subject: Re: [PATCH] net/failsafe: fix Rx interrupt reinstallation
>
> Hi Matan,
>
> On Tue, Feb 13, 2018 at 10:59:32PM +0000, Matan Azrad wrote:
> > Fail-safe dev_start() operation can be called by both the application
> > and the hot-plug alarm mechanism.
> >
> > The installation of Rx interrupt are triggered from dev_start() in any
> > time it is called while actually the Rx interrupt should be installed
> > only by the application calls.
> >
> > So, each plug-in event causes reinstallation which causes memory leak.
> >
> > Trigger the Rx interrupt installation only for application calls.
> >
> > Fixes: 9e0360aebf23 ("net/failsafe: register as Rx interrupt mode")
> >
> > Signed-off-by: Matan Azrad <matan@mellanox.com>
> > ---
> > drivers/net/failsafe/failsafe_ops.c | 10 ++++++----
> > 1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/net/failsafe/failsafe_ops.c
> > b/drivers/net/failsafe/failsafe_ops.c
> > index 057e435..bbbd335 100644
> > --- a/drivers/net/failsafe/failsafe_ops.c
> > +++ b/drivers/net/failsafe/failsafe_ops.c
> > @@ -181,10 +181,12 @@
> > int ret;
> >
> > fs_lock(dev, 0);
> > - ret = failsafe_rx_intr_install(dev);
> > - if (ret) {
> > - fs_unlock(dev, 0);
> > - return ret;
> > + if (PRIV(dev)->alarm_lock == 0) {
>
> I dislike having to rely on unrelated context of execution to decide a code-
> path.
>
> I'd prefer to make interrupt installation dependent on the interrupt state
> instead.
>
> I think it should be possible to forbid reinstallation within
> failsafe_rx_intr_install directly, e.g.
>
> diff --git a/drivers/net/failsafe/failsafe_intr.c
> b/drivers/net/failsafe/failsafe_intr.c
> index f6ff04dc8..46c3aa5f2 100644
> --- a/drivers/net/failsafe/failsafe_intr.c
> +++ b/drivers/net/failsafe/failsafe_intr.c
> @@ -523,7 +523,8 @@ failsafe_rx_intr_install(struct rte_eth_dev *dev)
> const struct rte_intr_conf *const intr_conf =
> &priv->dev->data->dev_conf.intr_conf;
>
> - if (intr_conf->rxq == 0)
> + if (intr_conf->rxq == 0 ||
> + dev->intr_handle != NULL)
> return 0;
> if (fs_rx_intr_vec_install(priv) < 0)
> return -rte_errno;
>
> This way the logic is self-dependent and the check limited to this component.
>
> There might be better way to do this, it's only an example to explain my
> point.
>
> > + ret = failsafe_rx_intr_install(dev);
> > + if (ret) {
> > + fs_unlock(dev, 0);
> > + return ret;
> > + }
> > }
> > FOREACH_SUBDEV(sdev, i, dev) {
> > if (sdev->state != DEV_ACTIVE)
> > --
> > 1.9.5
> >
>
> --
> Gaëtan Rivet
> 6WIND
@@ -523,7 +523,8 @@ failsafe_rx_intr_install(struct rte_eth_dev *dev)
const struct rte_intr_conf *const intr_conf =
&priv->dev->data->dev_conf.intr_conf;
- if (intr_conf->rxq == 0)
+ if (intr_conf->rxq == 0 ||
+ dev->intr_handle != NULL)
return 0;
if (fs_rx_intr_vec_install(priv) < 0)
return -rte_errno;