* [ath9k-devel] ath9k-rng: high cpu load
@ 2016-03-04 15:21 Oleksij Rempel
2016-03-11 9:46 ` miaoqing at codeaurora.org
0 siblings, 1 reply; 4+ messages in thread
From: Oleksij Rempel @ 2016-03-04 15:21 UTC (permalink / raw)
To: ath9k-devel
Hallo all,
on my last train trip i noticed that ath9k-rng produce continuous 15%
cpu load. Probably two factor coused this issue:
- my STA was not associated with any AP
- on the road there is enough noise.
from why i see, this code has all reasons to consume all CPU time it
get, so far ath9k_rng_data_read can provide some data.
while (!kthread_should_stop()) {
bytes_read = ath9k_rng_data_read(sc, rng_buf,
ATH9K_RNG_BUF_SIZE);
if (unlikely(!bytes_read)) {
msleep_interruptible(10);
continue;
}
/* sleep until entropy bits under write_wakeup_threshold */
add_hwgenerator_randomness((void *)rng_buf, bytes_read,
ATH9K_RNG_ENTROPY(bytes_read));
}
--
Regards,
Oleksij
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* [ath9k-devel] ath9k-rng: high cpu load
2016-03-04 15:21 [ath9k-devel] ath9k-rng: high cpu load Oleksij Rempel
@ 2016-03-11 9:46 ` miaoqing at codeaurora.org
2016-03-14 14:47 ` Oleksij Rempel
0 siblings, 1 reply; 4+ messages in thread
From: miaoqing at codeaurora.org @ 2016-03-11 9:46 UTC (permalink / raw)
To: ath9k-devel
Hi Oleksij,
Please try the attached patch. No valid ADC randomness will cause the issue.
--
Regards,
Miaoqing
> Hallo all,
>
> on my last train trip i noticed that ath9k-rng produce continuous 15%
> cpu load. Probably two factor coused this issue:
> - my STA was not associated with any AP
> - on the road there is enough noise.
>
> from why i see, this code has all reasons to consume all CPU time it
> get, so far ath9k_rng_data_read can provide some data.
>
> while (!kthread_should_stop()) {
> bytes_read = ath9k_rng_data_read(sc, rng_buf,
> ATH9K_RNG_BUF_SIZE);
> if (unlikely(!bytes_read)) {
> msleep_interruptible(10);
> continue;
> }
>
> /* sleep until entropy bits under write_wakeup_threshold
> */
> add_hwgenerator_randomness((void *)rng_buf, bytes_read,
> ATH9K_RNG_ENTROPY(bytes_read));
> }
>
> --
> Regards,
> Oleksij
>
>
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* [ath9k-devel] ath9k-rng: high cpu load
2016-03-11 9:46 ` miaoqing at codeaurora.org
@ 2016-03-14 14:47 ` Oleksij Rempel
2016-03-14 15:14 ` Oleksij Rempel
0 siblings, 1 reply; 4+ messages in thread
From: Oleksij Rempel @ 2016-03-14 14:47 UTC (permalink / raw)
To: ath9k-devel
Hi, compilation is filed with:
CC [M] drivers/net/wireless/ath/wcn36xx/smd.o
/home/oleksij/tmp/linux/drivers/net/wireless/ath/ath9k/rng.c: In
function ?ath9k_rng_delay_get?:
/home/oleksij/tmp/linux/drivers/net/wireless/ath/ath9k/rng.c:61:3:
error: ?delay? undeclared (first use in this function)
delay = 10;
^
/home/oleksij/tmp/linux/drivers/net/wireless/ath/ath9k/rng.c:61:3: note:
each undeclared identifier is reported only once for each function it
appears in
/home/oleksij/tmp/linux/drivers/net/wireless/ath/ath9k/rng.c:68:1:
warning: control reaches end of non-void function [-Wreturn-type]
}
^
/home/oleksij/tmp/linux/scripts/Makefile.build:258: recipe for target
'drivers/net/wireless/ath/ath9k/rng.o' failed
Am 11.03.2016 um 10:38 schrieb miaoqing at codeaurora.org:
> Hi Oleksij,
>
> Please try the attached patch. No valid ADC randomness will cause the issue.
>
> --
> Regards,
> Miaoqing
>
>
>> Hallo all,
>>
>> on my last train trip i noticed that ath9k-rng produce continuous 15%
>> cpu load. Probably two factor coused this issue:
>> - my STA was not associated with any AP
>> - on the road there is enough noise.
>>
>> from why i see, this code has all reasons to consume all CPU time it
>> get, so far ath9k_rng_data_read can provide some data.
>>
>> while (!kthread_should_stop()) {
>> bytes_read = ath9k_rng_data_read(sc, rng_buf,
>> ATH9K_RNG_BUF_SIZE);
>> if (unlikely(!bytes_read)) {
>> msleep_interruptible(10);
>> continue;
>> }
>>
>> /* sleep until entropy bits under write_wakeup_threshold
>> */
>> add_hwgenerator_randomness((void *)rng_buf, bytes_read,
>> ATH9K_RNG_ENTROPY(bytes_read));
>> }
>>
>> --
>> Regards,
>> Oleksij
>>
>>
--
Regards,
Oleksij
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* [ath9k-devel] ath9k-rng: high cpu load
2016-03-14 14:47 ` Oleksij Rempel
@ 2016-03-14 15:14 ` Oleksij Rempel
0 siblings, 0 replies; 4+ messages in thread
From: Oleksij Rempel @ 2016-03-14 15:14 UTC (permalink / raw)
To: ath9k-devel
After fixing compilation error it looks better now.
Am 14.03.2016 um 15:47 schrieb Oleksij Rempel:
> Hi, compilation is filed with:
>
> CC [M] drivers/net/wireless/ath/wcn36xx/smd.o
> /home/oleksij/tmp/linux/drivers/net/wireless/ath/ath9k/rng.c: In
> function ?ath9k_rng_delay_get?:
> /home/oleksij/tmp/linux/drivers/net/wireless/ath/ath9k/rng.c:61:3:
> error: ?delay? undeclared (first use in this function)
> delay = 10;
> ^
> /home/oleksij/tmp/linux/drivers/net/wireless/ath/ath9k/rng.c:61:3: note:
> each undeclared identifier is reported only once for each function it
> appears in
> /home/oleksij/tmp/linux/drivers/net/wireless/ath/ath9k/rng.c:68:1:
> warning: control reaches end of non-void function [-Wreturn-type]
> }
> ^
> /home/oleksij/tmp/linux/scripts/Makefile.build:258: recipe for target
> 'drivers/net/wireless/ath/ath9k/rng.o' failed
>
>
> Am 11.03.2016 um 10:38 schrieb miaoqing at codeaurora.org:
>> Hi Oleksij,
>>
>> Please try the attached patch. No valid ADC randomness will cause the issue.
>>
>> --
>> Regards,
>> Miaoqing
>>
>>
>>> Hallo all,
>>>
>>> on my last train trip i noticed that ath9k-rng produce continuous 15%
>>> cpu load. Probably two factor coused this issue:
>>> - my STA was not associated with any AP
>>> - on the road there is enough noise.
>>>
>>> from why i see, this code has all reasons to consume all CPU time it
>>> get, so far ath9k_rng_data_read can provide some data.
>>>
>>> while (!kthread_should_stop()) {
>>> bytes_read = ath9k_rng_data_read(sc, rng_buf,
>>> ATH9K_RNG_BUF_SIZE);
>>> if (unlikely(!bytes_read)) {
>>> msleep_interruptible(10);
>>> continue;
>>> }
>>>
>>> /* sleep until entropy bits under write_wakeup_threshold
>>> */
>>> add_hwgenerator_randomness((void *)rng_buf, bytes_read,
>>> ATH9K_RNG_ENTROPY(bytes_read));
>>> }
>>>
>>> --
>>> Regards,
>>> Oleksij
>>>
>>>
>
>
>
>
> _______________________________________________
> ath9k-devel mailing list
> ath9k-devel at lists.ath9k.org
> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>
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2016-03-04 15:21 [ath9k-devel] ath9k-rng: high cpu load Oleksij Rempel
2016-03-11 9:46 ` miaoqing at codeaurora.org
2016-03-14 14:47 ` Oleksij Rempel
2016-03-14 15:14 ` Oleksij Rempel
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