Stack usage reduced from 3024 (!) to 576.
Most of those 3k came from a bug:
#define IXGB_REG_DUMP_LEN 136*sizeof(uint32_t)
^^^^^^^^^^^^^^^^^
...
uint32_t regs_buff[IXGB_REG_DUMP_LEN];
Bug fixed. Two large on-stack variables moved to kmalloc space.
Stack usage is still high because gcc will
allocate too much space for these cases:
case ETHTOOL_GSET:{
struct ethtool_cmd ecmd = { ETHTOOL_GSET };
ixgb_ethtool_gset(adapter, &ecmd);
if (copy_to_user(addr, &ecmd, sizeof(ecmd)))
return -EFAULT;
return 0;
}
case ETHTOOL_SSET:{
struct ethtool_cmd ecmd;
if (copy_from_user(&ecmd, addr, sizeof(ecmd)))
return -EFAULT;
return ixgb_ethtool_sset(adapter, &ecmd);
}
There will be space for _two_ ecmd's on stack.
Shall it be worked around with ugly union of structs
or we'll just wait for better gcc?
Compile-tested only.
--
vda
On Sun, 2004-09-19 at 13:33, Denis Vlasenko wrote:
> Stack usage is still high because gcc will
> allocate too much space for these cases:
>
> case ETHTOOL_GSET:{
> struct ethtool_cmd ecmd = { ETHTOOL_GSET };
> ixgb_ethtool_gset(adapter, &ecmd);
> if (copy_to_user(addr, &ecmd, sizeof(ecmd)))
> return -EFAULT;
> return 0;
> }
> case ETHTOOL_SSET:{
> struct ethtool_cmd ecmd;
> if (copy_from_user(&ecmd, addr, sizeof(ecmd)))
> return -EFAULT;
> return ixgb_ethtool_sset(adapter, &ecmd);
> }
>
> There will be space for _two_ ecmd's on stack.
>
> Shall it be worked around with ugly union of structs
> or we'll just wait for better gcc?
You could convert it to use ethtool_ops.
--
Dave Dillow <[email protected]>
Dave Dillow wrote:
> On Sun, 2004-09-19 at 13:33, Denis Vlasenko wrote:
>
>>Stack usage is still high because gcc will
>>allocate too much space for these cases:
>>
>> case ETHTOOL_GSET:{
>> struct ethtool_cmd ecmd = { ETHTOOL_GSET };
>> ixgb_ethtool_gset(adapter, &ecmd);
>> if (copy_to_user(addr, &ecmd, sizeof(ecmd)))
>> return -EFAULT;
>> return 0;
>> }
>> case ETHTOOL_SSET:{
>> struct ethtool_cmd ecmd;
>> if (copy_from_user(&ecmd, addr, sizeof(ecmd)))
>> return -EFAULT;
>> return ixgb_ethtool_sset(adapter, &ecmd);
>> }
>>
>>There will be space for _two_ ecmd's on stack.
>>
>>Shall it be worked around with ugly union of structs
>>or we'll just wait for better gcc?
>
>
> You could convert it to use ethtool_ops.
Check -mm to make sure viro hasn't already converted it to ethtool_ops...
Jeff