Add support to set per-NAPI defer_hard_irqs and gro_flush_timeout.
Signed-off-by: Joe Damato <jdamato@fastly.com>
---
Documentation/netlink/specs/netdev.yaml | 11 ++++++
include/uapi/linux/netdev.h | 1 +
net/core/netdev-genl-gen.c | 18 ++++++++++
net/core/netdev-genl-gen.h | 1 +
net/core/netdev-genl.c | 45 +++++++++++++++++++++++++
tools/include/uapi/linux/netdev.h | 1 +
6 files changed, 77 insertions(+)
diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index bf13613eaa0d..7b4ea5a6e73d 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -690,6 +690,17 @@ operations:
reply:
attributes:
- id
+ -
+ name: napi-set
+ doc: Set configurable NAPI instance settings.
+ attribute-set: napi
+ flags: [ admin-perm ]
+ do:
+ request:
+ attributes:
+ - id
+ - defer-hard-irqs
+ - gro-flush-timeout
kernel-family:
headers: [ "linux/list.h"]
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index cacd33359c76..e3ebb49f60d2 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -201,6 +201,7 @@ enum {
NETDEV_CMD_NAPI_GET,
NETDEV_CMD_QSTATS_GET,
NETDEV_CMD_BIND_RX,
+ NETDEV_CMD_NAPI_SET,
__NETDEV_CMD_MAX,
NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)
diff --git a/net/core/netdev-genl-gen.c b/net/core/netdev-genl-gen.c
index b28424ae06d5..e197bd84997c 100644
--- a/net/core/netdev-genl-gen.c
+++ b/net/core/netdev-genl-gen.c
@@ -22,6 +22,10 @@ static const struct netlink_range_validation netdev_a_page_pool_ifindex_range =
.max = 2147483647ULL,
};
+static const struct netlink_range_validation netdev_a_napi_defer_hard_irqs_range = {
+ .max = 2147483647ULL,
+};
+
/* Common nested types */
const struct nla_policy netdev_page_pool_info_nl_policy[NETDEV_A_PAGE_POOL_IFINDEX + 1] = {
[NETDEV_A_PAGE_POOL_ID] = NLA_POLICY_FULL_RANGE(NLA_UINT, &netdev_a_page_pool_id_range),
@@ -87,6 +91,13 @@ static const struct nla_policy netdev_bind_rx_nl_policy[NETDEV_A_DMABUF_FD + 1]
[NETDEV_A_DMABUF_QUEUES] = NLA_POLICY_NESTED(netdev_queue_id_nl_policy),
};
+/* NETDEV_CMD_NAPI_SET - do */
+static const struct nla_policy netdev_napi_set_nl_policy[NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT + 1] = {
+ [NETDEV_A_NAPI_ID] = { .type = NLA_U32, },
+ [NETDEV_A_NAPI_DEFER_HARD_IRQS] = NLA_POLICY_FULL_RANGE(NLA_U32, &netdev_a_napi_defer_hard_irqs_range),
+ [NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT] = { .type = NLA_UINT, },
+};
+
/* Ops table for netdev */
static const struct genl_split_ops netdev_nl_ops[] = {
{
@@ -171,6 +182,13 @@ static const struct genl_split_ops netdev_nl_ops[] = {
.maxattr = NETDEV_A_DMABUF_FD,
.flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
},
+ {
+ .cmd = NETDEV_CMD_NAPI_SET,
+ .doit = netdev_nl_napi_set_doit,
+ .policy = netdev_napi_set_nl_policy,
+ .maxattr = NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT,
+ .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
+ },
};
static const struct genl_multicast_group netdev_nl_mcgrps[] = {
diff --git a/net/core/netdev-genl-gen.h b/net/core/netdev-genl-gen.h
index 8cda334fd042..e09dd7539ff2 100644
--- a/net/core/netdev-genl-gen.h
+++ b/net/core/netdev-genl-gen.h
@@ -33,6 +33,7 @@ int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
int netdev_nl_qstats_get_dumpit(struct sk_buff *skb,
struct netlink_callback *cb);
int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info);
+int netdev_nl_napi_set_doit(struct sk_buff *skb, struct genl_info *info);
enum {
NETDEV_NLGRP_MGMT,
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 64e5e4cee60d..59523318d620 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -303,6 +303,51 @@ int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
return err;
}
+static int
+netdev_nl_napi_set_config(struct napi_struct *napi, struct genl_info *info)
+{
+ u64 gro_flush_timeout = 0;
+ u32 defer = 0;
+
+ if (info->attrs[NETDEV_A_NAPI_DEFER_HARD_IRQS]) {
+ defer = nla_get_u32(info->attrs[NETDEV_A_NAPI_DEFER_HARD_IRQS]);
+ napi_set_defer_hard_irqs(napi, defer);
+ }
+
+ if (info->attrs[NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT]) {
+ gro_flush_timeout = nla_get_uint(info->attrs[NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT]);
+ napi_set_gro_flush_timeout(napi, gro_flush_timeout);
+ }
+
+ return 0;
+}
+
+int netdev_nl_napi_set_doit(struct sk_buff *skb, struct genl_info *info)
+{
+ struct napi_struct *napi;
+ unsigned int napi_id;
+ int err;
+
+ if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_NAPI_ID))
+ return -EINVAL;
+
+ napi_id = nla_get_u32(info->attrs[NETDEV_A_NAPI_ID]);
+
+ rtnl_lock();
+
+ napi = napi_by_id(napi_id);
+ if (napi) {
+ err = netdev_nl_napi_set_config(napi, info);
+ } else {
+ NL_SET_BAD_ATTR(info->extack, info->attrs[NETDEV_A_NAPI_ID]);
+ err = -ENOENT;
+ }
+
+ rtnl_unlock();
+
+ return err;
+}
+
static int
netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
u32 q_idx, u32 q_type, const struct genl_info *info)
diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index cacd33359c76..e3ebb49f60d2 100644
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -201,6 +201,7 @@ enum {
NETDEV_CMD_NAPI_GET,
NETDEV_CMD_QSTATS_GET,
NETDEV_CMD_BIND_RX,
+ NETDEV_CMD_NAPI_SET,
__NETDEV_CMD_MAX,
NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)
--
2.34.1On Wed, Oct 9, 2024 at 2:56 AM Joe Damato <jdamato@fastly.com> wrote:
>
> Add support to set per-NAPI defer_hard_irqs and gro_flush_timeout.
>
> Signed-off-by: Joe Damato <jdamato@fastly.com>
> ---
> Documentation/netlink/specs/netdev.yaml | 11 ++++++
> include/uapi/linux/netdev.h | 1 +
> net/core/netdev-genl-gen.c | 18 ++++++++++
> net/core/netdev-genl-gen.h | 1 +
> net/core/netdev-genl.c | 45 +++++++++++++++++++++++++
> tools/include/uapi/linux/netdev.h | 1 +
> 6 files changed, 77 insertions(+)
>
> diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
> index bf13613eaa0d..7b4ea5a6e73d 100644
> --- a/Documentation/netlink/specs/netdev.yaml
> +++ b/Documentation/netlink/specs/netdev.yaml
> @@ -690,6 +690,17 @@ operations:
> reply:
> attributes:
> - id
> + -
> + name: napi-set
> + doc: Set configurable NAPI instance settings.
> + attribute-set: napi
> + flags: [ admin-perm ]
> + do:
> + request:
> + attributes:
> + - id
> + - defer-hard-irqs
> + - gro-flush-timeout
>
> kernel-family:
> headers: [ "linux/list.h"]
> diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
> index cacd33359c76..e3ebb49f60d2 100644
> --- a/include/uapi/linux/netdev.h
> +++ b/include/uapi/linux/netdev.h
> @@ -201,6 +201,7 @@ enum {
> NETDEV_CMD_NAPI_GET,
> NETDEV_CMD_QSTATS_GET,
> NETDEV_CMD_BIND_RX,
> + NETDEV_CMD_NAPI_SET,
>
> __NETDEV_CMD_MAX,
> NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)
> diff --git a/net/core/netdev-genl-gen.c b/net/core/netdev-genl-gen.c
> index b28424ae06d5..e197bd84997c 100644
> --- a/net/core/netdev-genl-gen.c
> +++ b/net/core/netdev-genl-gen.c
> @@ -22,6 +22,10 @@ static const struct netlink_range_validation netdev_a_page_pool_ifindex_range =
> .max = 2147483647ULL,
> };
>
> +static const struct netlink_range_validation netdev_a_napi_defer_hard_irqs_range = {
> + .max = 2147483647ULL,
Would (u64)INT_MAX work ?
> +};
> +
> /* Common nested types */
> const struct nla_policy netdev_page_pool_info_nl_policy[NETDEV_A_PAGE_POOL_IFINDEX + 1] = {
> [NETDEV_A_PAGE_POOL_ID] = NLA_POLICY_FULL_RANGE(NLA_UINT, &netdev_a_page_pool_id_range),
> @@ -87,6 +91,13 @@ static const struct nla_policy netdev_bind_rx_nl_policy[NETDEV_A_DMABUF_FD + 1]
> [NETDEV_A_DMABUF_QUEUES] = NLA_POLICY_NESTED(netdev_queue_id_nl_policy),
> };
>
> +/* NETDEV_CMD_NAPI_SET - do */
> +static const struct nla_policy netdev_napi_set_nl_policy[NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT + 1] = {
> + [NETDEV_A_NAPI_ID] = { .type = NLA_U32, },
> + [NETDEV_A_NAPI_DEFER_HARD_IRQS] = NLA_POLICY_FULL_RANGE(NLA_U32, &netdev_a_napi_defer_hard_irqs_range),
> + [NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT] = { .type = NLA_UINT, },
> +};
> +
> /* Ops table for netdev */
> static const struct genl_split_ops netdev_nl_ops[] = {
> {
> @@ -171,6 +182,13 @@ static const struct genl_split_ops netdev_nl_ops[] = {
> .maxattr = NETDEV_A_DMABUF_FD,
> .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
> },
> + {
> + .cmd = NETDEV_CMD_NAPI_SET,
> + .doit = netdev_nl_napi_set_doit,
> + .policy = netdev_napi_set_nl_policy,
> + .maxattr = NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT,
> + .flags = GENL_ADMIN_PERM | GENL_CMD_CAP_DO,
> + },
> };
>
> static const struct genl_multicast_group netdev_nl_mcgrps[] = {
> diff --git a/net/core/netdev-genl-gen.h b/net/core/netdev-genl-gen.h
> index 8cda334fd042..e09dd7539ff2 100644
> --- a/net/core/netdev-genl-gen.h
> +++ b/net/core/netdev-genl-gen.h
> @@ -33,6 +33,7 @@ int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
> int netdev_nl_qstats_get_dumpit(struct sk_buff *skb,
> struct netlink_callback *cb);
> int netdev_nl_bind_rx_doit(struct sk_buff *skb, struct genl_info *info);
> +int netdev_nl_napi_set_doit(struct sk_buff *skb, struct genl_info *info);
>
> enum {
> NETDEV_NLGRP_MGMT,
> diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
> index 64e5e4cee60d..59523318d620 100644
> --- a/net/core/netdev-genl.c
> +++ b/net/core/netdev-genl.c
> @@ -303,6 +303,51 @@ int netdev_nl_napi_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb)
> return err;
> }
>
> +static int
> +netdev_nl_napi_set_config(struct napi_struct *napi, struct genl_info *info)
> +{
> + u64 gro_flush_timeout = 0;
> + u32 defer = 0;
> +
> + if (info->attrs[NETDEV_A_NAPI_DEFER_HARD_IRQS]) {
> + defer = nla_get_u32(info->attrs[NETDEV_A_NAPI_DEFER_HARD_IRQS]);
> + napi_set_defer_hard_irqs(napi, defer);
> + }
> +
> + if (info->attrs[NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT]) {
> + gro_flush_timeout = nla_get_uint(info->attrs[NETDEV_A_NAPI_GRO_FLUSH_TIMEOUT]);
> + napi_set_gro_flush_timeout(napi, gro_flush_timeout);
> + }
> +
> + return 0;
> +}
> +
> +int netdev_nl_napi_set_doit(struct sk_buff *skb, struct genl_info *info)
> +{
> + struct napi_struct *napi;
> + unsigned int napi_id;
> + int err;
> +
> + if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_NAPI_ID))
> + return -EINVAL;
> +
> + napi_id = nla_get_u32(info->attrs[NETDEV_A_NAPI_ID]);
> +
> + rtnl_lock();
Hmm.... please see my patch there :
https://patchwork.kernel.org/project/netdevbpf/patch/20241009232728.107604-2-edumazet@google.com/
Lets not add another rtnl_lock() :/
> +
> + napi = napi_by_id(napi_id);
> + if (napi) {
> + err = netdev_nl_napi_set_config(napi, info);
> + } else {
> + NL_SET_BAD_ATTR(info->extack, info->attrs[NETDEV_A_NAPI_ID]);
> + err = -ENOENT;
> + }
> +
> + rtnl_unlock();
> +
> + return err;
> +}
> +
> static int
> netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
> u32 q_idx, u32 q_type, const struct genl_info *info)
> diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
> index cacd33359c76..e3ebb49f60d2 100644
> --- a/tools/include/uapi/linux/netdev.h
> +++ b/tools/include/uapi/linux/netdev.h
> @@ -201,6 +201,7 @@ enum {
> NETDEV_CMD_NAPI_GET,
> NETDEV_CMD_QSTATS_GET,
> NETDEV_CMD_BIND_RX,
> + NETDEV_CMD_NAPI_SET,
>
> __NETDEV_CMD_MAX,
> NETDEV_CMD_MAX = (__NETDEV_CMD_MAX - 1)
> --
> 2.34.1
>
On Thu, 10 Oct 2024 06:24:54 +0200 Eric Dumazet wrote:
> > +static const struct netlink_range_validation netdev_a_napi_defer_hard_irqs_range = {
> > + .max = 2147483647ULL,
>
> Would (u64)INT_MAX work ?
I sent a codegen change for this. The codegen is a bit of a mess.
> > +int netdev_nl_napi_set_doit(struct sk_buff *skb, struct genl_info *info)
> > +{
> > + struct napi_struct *napi;
> > + unsigned int napi_id;
> > + int err;
> > +
> > + if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_NAPI_ID))
> > + return -EINVAL;
> > +
> > + napi_id = nla_get_u32(info->attrs[NETDEV_A_NAPI_ID]);
> > +
> > + rtnl_lock();
>
> Hmm.... please see my patch there :
>
> https://patchwork.kernel.org/project/netdevbpf/patch/20241009232728.107604-2-edumazet@google.com/
>
> Lets not add another rtnl_lock() :/
It's not as easy since NAPIs can come and go at driver's whim.
I'm quietly hoping we can convert all netdev-nl NAPI accesses
to use the netdev->lock protection I strong-armed Paolo into
adding in his shaper series. But perhaps we can do that after
this series? NAPI GET already takes RTNL lock.
On Thu, Oct 10, 2024 at 5:19 PM Jakub Kicinski <kuba@kernel.org> wrote:
>
> On Thu, 10 Oct 2024 06:24:54 +0200 Eric Dumazet wrote:
> > > +static const struct netlink_range_validation netdev_a_napi_defer_hard_irqs_range = {
> > > + .max = 2147483647ULL,
> >
> > Would (u64)INT_MAX work ?
>
> I sent a codegen change for this. The codegen is a bit of a mess.
>
> > > +int netdev_nl_napi_set_doit(struct sk_buff *skb, struct genl_info *info)
> > > +{
> > > + struct napi_struct *napi;
> > > + unsigned int napi_id;
> > > + int err;
> > > +
> > > + if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_NAPI_ID))
> > > + return -EINVAL;
> > > +
> > > + napi_id = nla_get_u32(info->attrs[NETDEV_A_NAPI_ID]);
> > > +
> > > + rtnl_lock();
> >
> > Hmm.... please see my patch there :
> >
> > https://patchwork.kernel.org/project/netdevbpf/patch/20241009232728.107604-2-edumazet@google.com/
> >
> > Lets not add another rtnl_lock() :/
>
> It's not as easy since NAPIs can come and go at driver's whim.
> I'm quietly hoping we can convert all netdev-nl NAPI accesses
> to use the netdev->lock protection I strong-armed Paolo into
> adding in his shaper series. But perhaps we can do that after
> this series? NAPI GET already takes RTNL lock.
napi_by_id() is protected by rcu and its own spinlock ( napi_hash_lock )
I do not see why rtnl is needed.
This will also be a big issue with per netns-RTNL anyway.
On Thu, Oct 10, 2024 at 05:30:26PM +0200, Eric Dumazet wrote:
> On Thu, Oct 10, 2024 at 5:19 PM Jakub Kicinski <kuba@kernel.org> wrote:
> >
> > On Thu, 10 Oct 2024 06:24:54 +0200 Eric Dumazet wrote:
> > > > +static const struct netlink_range_validation netdev_a_napi_defer_hard_irqs_range = {
> > > > + .max = 2147483647ULL,
> > >
> > > Would (u64)INT_MAX work ?
> >
> > I sent a codegen change for this. The codegen is a bit of a mess.
> >
> > > > +int netdev_nl_napi_set_doit(struct sk_buff *skb, struct genl_info *info)
> > > > +{
> > > > + struct napi_struct *napi;
> > > > + unsigned int napi_id;
> > > > + int err;
> > > > +
> > > > + if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_NAPI_ID))
> > > > + return -EINVAL;
> > > > +
> > > > + napi_id = nla_get_u32(info->attrs[NETDEV_A_NAPI_ID]);
> > > > +
> > > > + rtnl_lock();
> > >
> > > Hmm.... please see my patch there :
> > >
> > > https://patchwork.kernel.org/project/netdevbpf/patch/20241009232728.107604-2-edumazet@google.com/
> > >
> > > Lets not add another rtnl_lock() :/
> >
> > It's not as easy since NAPIs can come and go at driver's whim.
> > I'm quietly hoping we can convert all netdev-nl NAPI accesses
> > to use the netdev->lock protection I strong-armed Paolo into
> > adding in his shaper series. But perhaps we can do that after
> > this series? NAPI GET already takes RTNL lock.
>
>
> napi_by_id() is protected by rcu and its own spinlock ( napi_hash_lock )
> I do not see why rtnl is needed.
> This will also be a big issue with per netns-RTNL anyway.
I deeply appreciate and respect both of your thoughts on this; I
will hold off on sending a v6 until a decision is made on this
particular issue.
Thank you both for your careful review and analysis.
On Thu, Oct 10, 2024 at 6:40 PM Joe Damato <jdamato@fastly.com> wrote:
>
> On Thu, Oct 10, 2024 at 05:30:26PM +0200, Eric Dumazet wrote:
> > On Thu, Oct 10, 2024 at 5:19 PM Jakub Kicinski <kuba@kernel.org> wrote:
> > >
> > > On Thu, 10 Oct 2024 06:24:54 +0200 Eric Dumazet wrote:
> > > > > +static const struct netlink_range_validation netdev_a_napi_defer_hard_irqs_range = {
> > > > > + .max = 2147483647ULL,
> > > >
> > > > Would (u64)INT_MAX work ?
> > >
> > > I sent a codegen change for this. The codegen is a bit of a mess.
> > >
> > > > > +int netdev_nl_napi_set_doit(struct sk_buff *skb, struct genl_info *info)
> > > > > +{
> > > > > + struct napi_struct *napi;
> > > > > + unsigned int napi_id;
> > > > > + int err;
> > > > > +
> > > > > + if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_NAPI_ID))
> > > > > + return -EINVAL;
> > > > > +
> > > > > + napi_id = nla_get_u32(info->attrs[NETDEV_A_NAPI_ID]);
> > > > > +
> > > > > + rtnl_lock();
> > > >
> > > > Hmm.... please see my patch there :
> > > >
> > > > https://patchwork.kernel.org/project/netdevbpf/patch/20241009232728.107604-2-edumazet@google.com/
> > > >
> > > > Lets not add another rtnl_lock() :/
> > >
> > > It's not as easy since NAPIs can come and go at driver's whim.
> > > I'm quietly hoping we can convert all netdev-nl NAPI accesses
> > > to use the netdev->lock protection I strong-armed Paolo into
> > > adding in his shaper series. But perhaps we can do that after
> > > this series? NAPI GET already takes RTNL lock.
> >
> >
> > napi_by_id() is protected by rcu and its own spinlock ( napi_hash_lock )
> > I do not see why rtnl is needed.
> > This will also be a big issue with per netns-RTNL anyway.
>
> I deeply appreciate and respect both of your thoughts on this; I
> will hold off on sending a v6 until a decision is made on this
> particular issue.
>
I do not want to block your series.
Whatever is needed later, I can handle.
On Fri, Oct 11, 2024 at 07:19:47PM +0200, Eric Dumazet wrote:
> On Thu, Oct 10, 2024 at 6:40 PM Joe Damato <jdamato@fastly.com> wrote:
> >
> > On Thu, Oct 10, 2024 at 05:30:26PM +0200, Eric Dumazet wrote:
> > > On Thu, Oct 10, 2024 at 5:19 PM Jakub Kicinski <kuba@kernel.org> wrote:
> > > >
> > > > On Thu, 10 Oct 2024 06:24:54 +0200 Eric Dumazet wrote:
> > > > > > +static const struct netlink_range_validation netdev_a_napi_defer_hard_irqs_range = {
> > > > > > + .max = 2147483647ULL,
> > > > >
> > > > > Would (u64)INT_MAX work ?
> > > >
> > > > I sent a codegen change for this. The codegen is a bit of a mess.
> > > >
> > > > > > +int netdev_nl_napi_set_doit(struct sk_buff *skb, struct genl_info *info)
> > > > > > +{
> > > > > > + struct napi_struct *napi;
> > > > > > + unsigned int napi_id;
> > > > > > + int err;
> > > > > > +
> > > > > > + if (GENL_REQ_ATTR_CHECK(info, NETDEV_A_NAPI_ID))
> > > > > > + return -EINVAL;
> > > > > > +
> > > > > > + napi_id = nla_get_u32(info->attrs[NETDEV_A_NAPI_ID]);
> > > > > > +
> > > > > > + rtnl_lock();
> > > > >
> > > > > Hmm.... please see my patch there :
> > > > >
> > > > > https://patchwork.kernel.org/project/netdevbpf/patch/20241009232728.107604-2-edumazet@google.com/
> > > > >
> > > > > Lets not add another rtnl_lock() :/
> > > >
> > > > It's not as easy since NAPIs can come and go at driver's whim.
> > > > I'm quietly hoping we can convert all netdev-nl NAPI accesses
> > > > to use the netdev->lock protection I strong-armed Paolo into
> > > > adding in his shaper series. But perhaps we can do that after
> > > > this series? NAPI GET already takes RTNL lock.
> > >
> > >
> > > napi_by_id() is protected by rcu and its own spinlock ( napi_hash_lock )
> > > I do not see why rtnl is needed.
> > > This will also be a big issue with per netns-RTNL anyway.
> >
> > I deeply appreciate and respect both of your thoughts on this; I
> > will hold off on sending a v6 until a decision is made on this
> > particular issue.
> >
>
> I do not want to block your series.
>
> Whatever is needed later, I can handle.
Thank you, Eric.
I am happy to help with the future changes if needed. Feel free to
reach out if you'd like me to assist in any way as I know you have a
tremendous amount of work on your plate.
I will submit the v6 shortly, after I've rebased and retested.
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