Received-SPF: pass (google.com: best guess record for domain of linux-wireless-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Subject: Re: [PATCHv2] ath10k: Add wrapper function to ath10k debug
To:     =?UTF-8?Q?Micha=c5=82_Kazior?= <kazikcz@gmail.com>,
        Venkateswara Naralasetty <vnaralas@codeaurora.org>
Cc:     ath10k@lists.infradead.org,
        linux-wireless <linux-wireless@vger.kernel.org>,
        Kan Yan <kyan@chromium.org>
References: <1556283505-29539-1-git-send-email-vnaralas@codeaurora.org>
 <CABvG-CVxmnm=JsSsgYQqEzHHYU8RJDxqCZJn4Rzy=zPLtKY1hA@mail.gmail.com>
From:   Ben Greear <greearb@candelatech.com>
Organization: Candela Technologies
Message-ID: <52f8d2ff-9bd0-d456-e29a-c60b99a1eb8a@candelatech.com>
Date:   Fri, 26 Apr 2019 06:56:30 -0700
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101
 Thunderbird/60.4.0
MIME-Version: 1.0
In-Reply-To: <CABvG-CVxmnm=JsSsgYQqEzHHYU8RJDxqCZJn4Rzy=zPLtKY1hA@mail.gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Language: en-US
Content-Transfer-Encoding: 8bit
Sender: linux-wireless-owner@vger.kernel.org
Precedence: bulk

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