From: Aharon Landau <[email protected]>
This patch adds the ability to get the name, index and status of all
counters for each link through RDMA netlink. This can be used for
user-space to get the current optional-counter mode.
Examples:
$ rdma statistic mode
link rocep8s0f0/1 optional-counters cc_rx_ce_pkts
$ rdma statistic mode supported
link rocep8s0f0/1 supported optional-counters cc_rx_ce_pkts,cc_rx_cnp_pkts,cc_tx_cnp_pkts
link rocep8s0f1/1 supported optional-counters cc_rx_ce_pkts,cc_rx_cnp_pkts,cc_tx_cnp_pkts
Signed-off-by: Aharon Landau <[email protected]>
Signed-off-by: Neta Ostrovsky <[email protected]>
Reviewed-by: Mark Zhang <[email protected]>
Signed-off-by: Leon Romanovsky <[email protected]>
---
drivers/infiniband/core/nldev.c | 154 +++++++++++++++++++++++--------
include/uapi/rdma/rdma_netlink.h | 3 +
2 files changed, 121 insertions(+), 36 deletions(-)
diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
index 67519730b1ac..d9443983efdc 100644
--- a/drivers/infiniband/core/nldev.c
+++ b/drivers/infiniband/core/nldev.c
@@ -154,6 +154,8 @@ static const struct nla_policy nldev_policy[RDMA_NLDEV_ATTR_MAX] = {
[RDMA_NLDEV_NET_NS_FD] = { .type = NLA_U32 },
[RDMA_NLDEV_SYS_ATTR_NETNS_MODE] = { .type = NLA_U8 },
[RDMA_NLDEV_SYS_ATTR_COPY_ON_FORK] = { .type = NLA_U8 },
+ [RDMA_NLDEV_ATTR_STAT_HWCOUNTER_INDEX] = { .type = NLA_U32 },
+ [RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC] = { .type = NLA_U8 },
};
static int put_driver_name_print_type(struct sk_buff *msg, const char *name,
@@ -2046,49 +2048,90 @@ static int nldev_stat_del_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
return ret;
}
-static int stat_get_doit_default_counter(struct sk_buff *skb,
- struct nlmsghdr *nlh,
- struct netlink_ext_ack *extack,
- struct nlattr *tb[])
+static int stat_get_doit_stats_list(struct sk_buff *skb,
+ struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack,
+ struct nlattr *tb[],
+ struct ib_device *device, u32 port,
+ struct rdma_hw_stats *stats)
{
- struct rdma_hw_stats *stats;
- struct nlattr *table_attr;
- struct ib_device *device;
- int ret, num_cnts, i;
+ struct nlattr *table, *entry;
struct sk_buff *msg;
- u32 index, port;
- u64 v;
+ int i;
- if (!tb[RDMA_NLDEV_ATTR_DEV_INDEX] || !tb[RDMA_NLDEV_ATTR_PORT_INDEX])
- return -EINVAL;
+ msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
- index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
- device = ib_device_get_by_index(sock_net(skb->sk), index);
- if (!device)
- return -EINVAL;
+ nlh = nlmsg_put(
+ msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
+ RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_STAT_GET), 0, 0);
- if (!device->ops.alloc_hw_port_stats || !device->ops.get_hw_stats) {
- ret = -EINVAL;
- goto err;
- }
+ if (fill_nldev_handle(msg, device) ||
+ nla_put_u32(msg, RDMA_NLDEV_ATTR_PORT_INDEX, port))
+ goto err_msg;
- port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
- stats = ib_get_hw_stats_port(device, port);
- if (!stats) {
- ret = -EINVAL;
- goto err;
+ table = nla_nest_start(msg, RDMA_NLDEV_ATTR_STAT_HWCOUNTERS);
+ if (!table)
+ goto err_msg;
+
+ mutex_lock(&stats->lock);
+ for (i = 0; i < stats->num_counters; i++) {
+ entry = nla_nest_start(msg,
+ RDMA_NLDEV_ATTR_STAT_HWCOUNTER_ENTRY);
+ if (!entry)
+ goto err_msg_table;
+
+ if (nla_put_string(msg,
+ RDMA_NLDEV_ATTR_STAT_HWCOUNTER_ENTRY_NAME,
+ stats->descs[i].name) ||
+ nla_put_u32(msg, RDMA_NLDEV_ATTR_STAT_HWCOUNTER_INDEX, i))
+ goto err_msg_entry;
+
+ if ((stats->descs[i].flags & IB_STAT_FLAG_OPTIONAL) &&
+ (nla_put_u8(msg, RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC,
+ !test_bit(i, stats->is_disabled))))
+ goto err_msg_entry;
+
+ nla_nest_end(msg, entry);
}
+ mutex_unlock(&stats->lock);
+
+ nla_nest_end(msg, table);
+ nlmsg_end(msg, nlh);
+ return rdma_nl_unicast(sock_net(skb->sk), msg, NETLINK_CB(skb).portid);
+
+err_msg_entry:
+ nla_nest_cancel(msg, entry);
+err_msg_table:
+ mutex_unlock(&stats->lock);
+ nla_nest_cancel(msg, table);
+err_msg:
+ nlmsg_free(msg);
+ return -EMSGSIZE;
+}
+
+static int stat_get_doit_stats_values(struct sk_buff *skb, struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack,
+ struct nlattr *tb[],
+ struct ib_device *device, u32 port,
+ struct rdma_hw_stats *stats)
+{
+ struct nlattr *table_attr;
+ int ret, num_cnts, i;
+ struct sk_buff *msg;
+ u64 v;
+
+ if (!device->ops.alloc_hw_port_stats || !device->ops.get_hw_stats)
+ return -EINVAL;
msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
- if (!msg) {
- ret = -ENOMEM;
- goto err;
- }
+ if (!msg)
+ return -ENOMEM;
- nlh = nlmsg_put(msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
- RDMA_NL_GET_TYPE(RDMA_NL_NLDEV,
- RDMA_NLDEV_CMD_STAT_GET),
- 0, 0);
+ nlh = nlmsg_put(
+ msg, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
+ RDMA_NL_GET_TYPE(RDMA_NL_NLDEV, RDMA_NLDEV_CMD_STAT_GET), 0, 0);
if (fill_nldev_handle(msg, device) ||
nla_put_u32(msg, RDMA_NLDEV_ATTR_PORT_INDEX, port)) {
@@ -2098,7 +2141,8 @@ static int stat_get_doit_default_counter(struct sk_buff *skb,
mutex_lock(&stats->lock);
- num_cnts = device->ops.get_hw_stats(device, stats, port, 0);
+ num_cnts = device->ops.get_hw_stats(device, stats, port,
+ stats->num_counters);
if (num_cnts < 0) {
ret = -EINVAL;
goto err_stats;
@@ -2125,7 +2169,6 @@ static int stat_get_doit_default_counter(struct sk_buff *skb,
mutex_unlock(&stats->lock);
nlmsg_end(msg, nlh);
- ib_device_put(device);
return rdma_nl_unicast(sock_net(skb->sk), msg, NETLINK_CB(skb).portid);
err_table:
@@ -2134,7 +2177,46 @@ static int stat_get_doit_default_counter(struct sk_buff *skb,
mutex_unlock(&stats->lock);
err_msg:
nlmsg_free(msg);
-err:
+ return ret;
+}
+
+static int stat_get_doit_default_counter(struct sk_buff *skb,
+ struct nlmsghdr *nlh,
+ struct netlink_ext_ack *extack,
+ struct nlattr *tb[])
+{
+ struct rdma_hw_stats *stats;
+ struct ib_device *device;
+ u32 index, port;
+ int ret;
+
+ if (!tb[RDMA_NLDEV_ATTR_DEV_INDEX] || !tb[RDMA_NLDEV_ATTR_PORT_INDEX])
+ return -EINVAL;
+
+ index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
+ device = ib_device_get_by_index(sock_net(skb->sk), index);
+ if (!device)
+ return -EINVAL;
+
+ port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
+ if (!rdma_is_port_valid(device, port)) {
+ ret = -EINVAL;
+ goto end;
+ }
+
+ stats = ib_get_hw_stats_port(device, port);
+ if (!stats) {
+ ret = -EINVAL;
+ goto end;
+ }
+
+ if (tb[RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC])
+ ret = stat_get_doit_stats_list(skb, nlh, extack, tb,
+ device, port, stats);
+ else
+ ret = stat_get_doit_stats_values(skb, nlh, extack, tb, device,
+ port, stats);
+end:
ib_device_put(device);
return ret;
}
diff --git a/include/uapi/rdma/rdma_netlink.h b/include/uapi/rdma/rdma_netlink.h
index 75a1ae2311d8..2017970279ed 100644
--- a/include/uapi/rdma/rdma_netlink.h
+++ b/include/uapi/rdma/rdma_netlink.h
@@ -549,6 +549,9 @@ enum rdma_nldev_attr {
RDMA_NLDEV_SYS_ATTR_COPY_ON_FORK, /* u8 */
+ RDMA_NLDEV_ATTR_STAT_HWCOUNTER_INDEX, /* u32 */
+ RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC, /* u8 */
+
/*
* Always the end
*/
--
2.31.1
On Wed, Sep 15, 2021 at 02:07:25AM +0300, Leon Romanovsky wrote:
> +static int stat_get_doit_default_counter(struct sk_buff *skb,
> + struct nlmsghdr *nlh,
> + struct netlink_ext_ack *extack,
> + struct nlattr *tb[])
> +{
> + struct rdma_hw_stats *stats;
> + struct ib_device *device;
> + u32 index, port;
> + int ret;
> +
> + if (!tb[RDMA_NLDEV_ATTR_DEV_INDEX] || !tb[RDMA_NLDEV_ATTR_PORT_INDEX])
> + return -EINVAL;
> +
> + index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
> + device = ib_device_get_by_index(sock_net(skb->sk), index);
> + if (!device)
> + return -EINVAL;
> +
> + port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
> + if (!rdma_is_port_valid(device, port)) {
> + ret = -EINVAL;
> + goto end;
> + }
> +
> + stats = ib_get_hw_stats_port(device, port);
> + if (!stats) {
> + ret = -EINVAL;
> + goto end;
> + }
> +
> + if (tb[RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC])
> + ret = stat_get_doit_stats_list(skb, nlh, extack, tb,
> + device, port, stats);
> + else
> + ret = stat_get_doit_stats_values(skb, nlh, extack, tb, device,
> + port, stats);
This seems strange, why is the output of a get contingent on a ignored
input attribute? Shouldn't the HWCOUNTER_DYNAMIC just always be
emitted?
Jason
On 9/28/2021 1:30 AM, Jason Gunthorpe wrote:
> On Wed, Sep 15, 2021 at 02:07:25AM +0300, Leon Romanovsky wrote:
>> +static int stat_get_doit_default_counter(struct sk_buff *skb,
>> + struct nlmsghdr *nlh,
>> + struct netlink_ext_ack *extack,
>> + struct nlattr *tb[])
>> +{
>> + struct rdma_hw_stats *stats;
>> + struct ib_device *device;
>> + u32 index, port;
>> + int ret;
>> +
>> + if (!tb[RDMA_NLDEV_ATTR_DEV_INDEX] || !tb[RDMA_NLDEV_ATTR_PORT_INDEX])
>> + return -EINVAL;
>> +
>> + index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
>> + device = ib_device_get_by_index(sock_net(skb->sk), index);
>> + if (!device)
>> + return -EINVAL;
>> +
>> + port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
>> + if (!rdma_is_port_valid(device, port)) {
>> + ret = -EINVAL;
>> + goto end;
>> + }
>> +
>> + stats = ib_get_hw_stats_port(device, port);
>> + if (!stats) {
>> + ret = -EINVAL;
>> + goto end;
>> + }
>> +
>> + if (tb[RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC])
>> + ret = stat_get_doit_stats_list(skb, nlh, extack, tb,
>> + device, port, stats);
>> + else
>> + ret = stat_get_doit_stats_values(skb, nlh, extack, tb, device,
>> + port, stats);
>
> This seems strange, why is the output of a get contingent on a ignored
> input attribute? Shouldn't the HWCOUNTER_DYNAMIC just always be
> emitted?
The CMD_STAT_GET is originally used to get the default hwcounter
statistic (the value of all hwstats), now we also want to use this
command to get a list of counters (just name and status), so kernel
differentiates these 2 cases based on HWCOUNTER_DYNAMIC attr.
On Tue, Sep 28, 2021 at 05:12:39PM +0800, Mark Zhang wrote:
> On 9/28/2021 1:30 AM, Jason Gunthorpe wrote:
> > On Wed, Sep 15, 2021 at 02:07:25AM +0300, Leon Romanovsky wrote:
> > > +static int stat_get_doit_default_counter(struct sk_buff *skb,
> > > + struct nlmsghdr *nlh,
> > > + struct netlink_ext_ack *extack,
> > > + struct nlattr *tb[])
> > > +{
> > > + struct rdma_hw_stats *stats;
> > > + struct ib_device *device;
> > > + u32 index, port;
> > > + int ret;
> > > +
> > > + if (!tb[RDMA_NLDEV_ATTR_DEV_INDEX] || !tb[RDMA_NLDEV_ATTR_PORT_INDEX])
> > > + return -EINVAL;
> > > +
> > > + index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
> > > + device = ib_device_get_by_index(sock_net(skb->sk), index);
> > > + if (!device)
> > > + return -EINVAL;
> > > +
> > > + port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
> > > + if (!rdma_is_port_valid(device, port)) {
> > > + ret = -EINVAL;
> > > + goto end;
> > > + }
> > > +
> > > + stats = ib_get_hw_stats_port(device, port);
> > > + if (!stats) {
> > > + ret = -EINVAL;
> > > + goto end;
> > > + }
> > > +
> > > + if (tb[RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC])
> > > + ret = stat_get_doit_stats_list(skb, nlh, extack, tb,
> > > + device, port, stats);
> > > + else
> > > + ret = stat_get_doit_stats_values(skb, nlh, extack, tb, device,
> > > + port, stats);
> >
> > This seems strange, why is the output of a get contingent on a ignored
> > input attribute? Shouldn't the HWCOUNTER_DYNAMIC just always be
> > emitted?
>
> The CMD_STAT_GET is originally used to get the default hwcounter statistic
> (the value of all hwstats), now we also want to use this command to get a
> list of counters (just name and status), so kernel differentiates these 2
> cases based on HWCOUNTER_DYNAMIC attr.
Don't do that, it is not how netlink works. Either the whole attribute
should be returned or you need a new get command
Jason
On 9/28/2021 7:52 PM, Jason Gunthorpe wrote:
> On Tue, Sep 28, 2021 at 05:12:39PM +0800, Mark Zhang wrote:
>> On 9/28/2021 1:30 AM, Jason Gunthorpe wrote:
>>> On Wed, Sep 15, 2021 at 02:07:25AM +0300, Leon Romanovsky wrote:
>>>> +static int stat_get_doit_default_counter(struct sk_buff *skb,
>>>> + struct nlmsghdr *nlh,
>>>> + struct netlink_ext_ack *extack,
>>>> + struct nlattr *tb[])
>>>> +{
>>>> + struct rdma_hw_stats *stats;
>>>> + struct ib_device *device;
>>>> + u32 index, port;
>>>> + int ret;
>>>> +
>>>> + if (!tb[RDMA_NLDEV_ATTR_DEV_INDEX] || !tb[RDMA_NLDEV_ATTR_PORT_INDEX])
>>>> + return -EINVAL;
>>>> +
>>>> + index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
>>>> + device = ib_device_get_by_index(sock_net(skb->sk), index);
>>>> + if (!device)
>>>> + return -EINVAL;
>>>> +
>>>> + port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
>>>> + if (!rdma_is_port_valid(device, port)) {
>>>> + ret = -EINVAL;
>>>> + goto end;
>>>> + }
>>>> +
>>>> + stats = ib_get_hw_stats_port(device, port);
>>>> + if (!stats) {
>>>> + ret = -EINVAL;
>>>> + goto end;
>>>> + }
>>>> +
>>>> + if (tb[RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC])
>>>> + ret = stat_get_doit_stats_list(skb, nlh, extack, tb,
>>>> + device, port, stats);
>>>> + else
>>>> + ret = stat_get_doit_stats_values(skb, nlh, extack, tb, device,
>>>> + port, stats);
>>>
>>> This seems strange, why is the output of a get contingent on a ignored
>>> input attribute? Shouldn't the HWCOUNTER_DYNAMIC just always be
>>> emitted?
>>
>> The CMD_STAT_GET is originally used to get the default hwcounter statistic
>> (the value of all hwstats), now we also want to use this command to get a
>> list of counters (just name and status), so kernel differentiates these 2
>> cases based on HWCOUNTER_DYNAMIC attr.
>
> Don't do that, it is not how netlink works. Either the whole attribute
> should be returned or you need a new get command
Will add a new get command for backward compatibility, thanks.
On Tue, Sep 28, 2021 at 08:52:17AM -0300, Jason Gunthorpe wrote:
> On Tue, Sep 28, 2021 at 05:12:39PM +0800, Mark Zhang wrote:
> > On 9/28/2021 1:30 AM, Jason Gunthorpe wrote:
> > > On Wed, Sep 15, 2021 at 02:07:25AM +0300, Leon Romanovsky wrote:
> > > > +static int stat_get_doit_default_counter(struct sk_buff *skb,
> > > > + struct nlmsghdr *nlh,
> > > > + struct netlink_ext_ack *extack,
> > > > + struct nlattr *tb[])
> > > > +{
> > > > + struct rdma_hw_stats *stats;
> > > > + struct ib_device *device;
> > > > + u32 index, port;
> > > > + int ret;
> > > > +
> > > > + if (!tb[RDMA_NLDEV_ATTR_DEV_INDEX] || !tb[RDMA_NLDEV_ATTR_PORT_INDEX])
> > > > + return -EINVAL;
> > > > +
> > > > + index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
> > > > + device = ib_device_get_by_index(sock_net(skb->sk), index);
> > > > + if (!device)
> > > > + return -EINVAL;
> > > > +
> > > > + port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
> > > > + if (!rdma_is_port_valid(device, port)) {
> > > > + ret = -EINVAL;
> > > > + goto end;
> > > > + }
> > > > +
> > > > + stats = ib_get_hw_stats_port(device, port);
> > > > + if (!stats) {
> > > > + ret = -EINVAL;
> > > > + goto end;
> > > > + }
> > > > +
> > > > + if (tb[RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC])
> > > > + ret = stat_get_doit_stats_list(skb, nlh, extack, tb,
> > > > + device, port, stats);
> > > > + else
> > > > + ret = stat_get_doit_stats_values(skb, nlh, extack, tb, device,
> > > > + port, stats);
> > >
> > > This seems strange, why is the output of a get contingent on a ignored
> > > input attribute? Shouldn't the HWCOUNTER_DYNAMIC just always be
> > > emitted?
> >
> > The CMD_STAT_GET is originally used to get the default hwcounter statistic
> > (the value of all hwstats), now we also want to use this command to get a
> > list of counters (just name and status), so kernel differentiates these 2
> > cases based on HWCOUNTER_DYNAMIC attr.
>
> Don't do that, it is not how netlink works. Either the whole attribute
> should be returned or you need a new get command
The netlink way is to be independent on returned parameter, if it not
supported, this parameter won't be available at all. This makes HWCOUNTER_DYNAMIC
to work exactly as netlink would do.
Thanks
>
> Jason
On Wed, Sep 29, 2021 at 03:26:25PM +0300, Leon Romanovsky wrote:
> On Tue, Sep 28, 2021 at 08:52:17AM -0300, Jason Gunthorpe wrote:
> > On Tue, Sep 28, 2021 at 05:12:39PM +0800, Mark Zhang wrote:
> > > On 9/28/2021 1:30 AM, Jason Gunthorpe wrote:
> > > > On Wed, Sep 15, 2021 at 02:07:25AM +0300, Leon Romanovsky wrote:
> > > > > +static int stat_get_doit_default_counter(struct sk_buff *skb,
> > > > > + struct nlmsghdr *nlh,
> > > > > + struct netlink_ext_ack *extack,
> > > > > + struct nlattr *tb[])
> > > > > +{
> > > > > + struct rdma_hw_stats *stats;
> > > > > + struct ib_device *device;
> > > > > + u32 index, port;
> > > > > + int ret;
> > > > > +
> > > > > + if (!tb[RDMA_NLDEV_ATTR_DEV_INDEX] || !tb[RDMA_NLDEV_ATTR_PORT_INDEX])
> > > > > + return -EINVAL;
> > > > > +
> > > > > + index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);
> > > > > + device = ib_device_get_by_index(sock_net(skb->sk), index);
> > > > > + if (!device)
> > > > > + return -EINVAL;
> > > > > +
> > > > > + port = nla_get_u32(tb[RDMA_NLDEV_ATTR_PORT_INDEX]);
> > > > > + if (!rdma_is_port_valid(device, port)) {
> > > > > + ret = -EINVAL;
> > > > > + goto end;
> > > > > + }
> > > > > +
> > > > > + stats = ib_get_hw_stats_port(device, port);
> > > > > + if (!stats) {
> > > > > + ret = -EINVAL;
> > > > > + goto end;
> > > > > + }
> > > > > +
> > > > > + if (tb[RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC])
> > > > > + ret = stat_get_doit_stats_list(skb, nlh, extack, tb,
> > > > > + device, port, stats);
> > > > > + else
> > > > > + ret = stat_get_doit_stats_values(skb, nlh, extack, tb, device,
> > > > > + port, stats);
> > > >
> > > > This seems strange, why is the output of a get contingent on a ignored
> > > > input attribute? Shouldn't the HWCOUNTER_DYNAMIC just always be
> > > > emitted?
> > >
> > > The CMD_STAT_GET is originally used to get the default hwcounter statistic
> > > (the value of all hwstats), now we also want to use this command to get a
> > > list of counters (just name and status), so kernel differentiates these 2
> > > cases based on HWCOUNTER_DYNAMIC attr.
> >
> > Don't do that, it is not how netlink works. Either the whole attribute
> > should be returned or you need a new get command
>
> The netlink way is to be independent on returned parameter, if it not
> supported, this parameter won't be available at all. This makes HWCOUNTER_DYNAMIC
> to work exactly as netlink would do.
The issue is making the output dependent on the input:
+ if (tb[RDMA_NLDEV_ATTR_STAT_HWCOUNTER_DYNAMIC])
Setting HWCOUNTER_DYNAMIC as an input flag to get the GET to return a
completely different output format is not netlinky
Either always return HWCOUNTER_DYNAMIC or make another query to get it
Jason