Re: [PATCHv2] ath10k: Add wrapper function to ath10k debug

[Ben Greear <greearb@candelatech.com>]

On 4/26/19 6:44 AM, Michał Kazior wrote:
> On Fri, 26 Apr 2019 at 14:58, Venkateswara Naralasetty
> <vnaralas@codeaurora.org> wrote:
>>
>> ath10k_dbg() is called in ath10k_process_rx() with huge set of arguments
>> which is causing CPU overhead even when debug_mask is not set.
>> Good improvement was observed in the receive side performance when call
>> to ath10k_dbg() is avoided in the RX path.
> [...]
> 
>> +/* Avoid calling __ath10k_dbg() if debug_mask is not set and tracing
>> + * disabled.
>> + */
>> +#define ath10k_dbg(ar, dbg_mask, fmt, ...)                     \
>> +do {                                                           \
>> +       if ((ath10k_debug_mask & dbg_mask) ||                   \
>> +           trace_ath10k_log_dbg_enabled())                     \
>> +               __ath10k_dbg(ar, dbg_mask, fmt, ##__VA_ARGS__); \
>> +} while (0)
> 
> Did you consider using jump labels (see include/linux/jump_label.h)?
> It's what tracing uses under the hood. I wonder if you could squeeze
> out a bit more performance with that? I guess you'd need to add
> `struct static_key ath10k_dbg_mask_keys[ATH10K_DBG_MAX]` and re-do
> ath10k_debug_mask enum a bit.

Maybe first test with debugging just compiled out to see if there is still
any significant overhead with this new patch applied?

Thanks,
Ben

-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com