On 08.10.2018 22:07, Randy Dunlap wrote:
> On 10/8/18 1:00 PM, Heiner Kallweit wrote:
>> bool is good as parameter type or function return type, but if used
>> for struct members it consumes more memory than needed.
>> Changing the bool members of struct net_device to bitfield members
>> allows to decrease the memory footprint of this struct.
>>
>> Signed-off-by: Heiner Kallweit <hkallwe...@gmail.com>
>> ---
>> include/linux/netdevice.h | 24 +++++++++++++-----------
>> 1 file changed, 13 insertions(+), 11 deletions(-)
>>
>> diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
>> index 76603ee13..3d7b8df2e 100644
>> --- a/include/linux/netdevice.h
>> +++ b/include/linux/netdevice.h
>> @@ -1651,10 +1651,6 @@ enum netdev_priv_flags {
>> * @dev_port: Used to differentiate devices that share
>> * the same function
>> * @addr_list_lock: XXX: need comments on this one
>> - * @uc_promisc: Counter that indicates promiscuous mode
>> - * has been enabled due to the need to listen to
>> - * additional unicast addresses in a device that
>> - * does not implement ndo_set_rx_mode()
>> * @uc: unicast mac addresses
>> * @mc: multicast mac addresses
>> * @dev_addrs: list of device hw addresses
>> @@ -1714,11 +1710,9 @@ enum netdev_priv_flags {
>> * @link_watch_list: XXX: need comments on this one
>> *
>> * @reg_state: Register/unregister state machine
>> - * @dismantle: Device is going to be freed
>> * @rtnl_link_state: This enum represents the phases of creating
>> * a new link
>> *
>> - * @needs_free_netdev: Should unregister perform free_netdev?
>> * @priv_destructor: Called from unregister
>> * @npinfo: XXX: need comments on this one
>> * @nd_net: Network namespace this network device is inside
>> @@ -1758,6 +1752,15 @@ enum netdev_priv_flags {
>> * @qdisc_tx_busylock: lockdep class annotating Qdisc->busylock spinlock
>> * @qdisc_running_key: lockdep class annotating Qdisc->running seqcount
>> *
>> + * @uc_promisc: Counter that indicates promiscuous mode
>> + * has been enabled due to the need to listen to
>> + * additional unicast addresses in a device that
>> + * does not implement ndo_set_rx_mode()
>
> Hi,
>
> I see that all you did is copy/paste that text (above), but I wouldn't call
> a single bit a [1-bit] Counter.
>
I stumbled across this comment too. Neither a bool member nor a 1-bit
bitfield member should be called a counter. I kept the original comment,
but I'm totally fine with changing Counter -> Flag and will provide a v2.
> thanks,
>
