[lttng-dev] cds_lfht_resize() and QSBR

[lttng-dev] cds_lfht_resize() and QSBR

[Eugene Ivanov]

Hi,

According documentation "cds_lfht_resize should *not* be called from a
RCU read-side critical section", can I use this function with QSBR,
where almost everything is read-side CS? And cds_lfht_destroy()?

--
Eugene Ivanov


________________________________

This e-mail is confidential and may contain legally privileged information. It is intended only for the addressees. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message from your system.

[lttng-dev] cds_lfht_resize() and QSBR

[Mathieu Desnoyers]

Hi Eugene,

It's fine to use both lfht resize and destroy from URCU QSBR, because
we explicitly mark the threads "offline" (saving the old state),
and restore the original state, at the beginning and end of those
functions.

However, calls to cds_lfht_resize() and cds_lfht_destroy are considered
as an explicit quiescent state in URCU QSBR, therefore, don't expect
your RCU read-side critical section to extend across those 2 calls.

Thanks,

Mathieu

----- On Jul 27, 2015, at 12:03 PM, Eugene Ivanov Eugene.Ivanov at orc-group.com wrote:

> Hi,
> 
> According documentation "cds_lfht_resize should *not* be called from a
> RCU read-side critical section", can I use this function with QSBR,
> where almost everything is read-side CS? And cds_lfht_destroy()?
> 
> --
> Eugene Ivanov
> 
> 
> ________________________________
> 
> This e-mail is confidential and may contain legally privileged information. It
> is intended only for the addressees. If you have received this e-mail in error,
> kindly notify us immediately by telephone or e-mail and delete the message from
> your system.
> 
> _______________________________________________
> lttng-dev mailing list
> lttng-dev at lists.lttng.org
> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

[lttng-dev] cds_lfht_resize() and QSBR

[Eugene Ivanov]

Thank you, Mathieu!

On 07/27/2015 08:12 PM, Mathieu Desnoyers wrote:
> Hi Eugene,
>
> It's fine to use both lfht resize and destroy from URCU QSBR, because
> we explicitly mark the threads "offline" (saving the old state),
> and restore the original state, at the beginning and end of those
> functions.
>
> However, calls to cds_lfht_resize() and cds_lfht_destroy are considered
> as an explicit quiescent state in URCU QSBR, therefore, don't expect
> your RCU read-side critical section to extend across those 2 calls.
>
> Thanks,
>
> Mathieu
>
> ----- On Jul 27, 2015, at 12:03 PM, Eugene Ivanov Eugene.Ivanov at orc-group.com wrote:
>
>> Hi,
>>
>> According documentation "cds_lfht_resize should *not* be called from a
>> RCU read-side critical section", can I use this function with QSBR,
>> where almost everything is read-side CS? And cds_lfht_destroy()?
>>
>> --
>> Eugene Ivanov
>>
>>
>> ________________________________
>>
>> This e-mail is confidential and may contain legally privileged information. It
>> is intended only for the addressees. If you have received this e-mail in error,
>> kindly notify us immediately by telephone or e-mail and delete the message from
>> your system.
>>
>> _______________________________________________
>> lttng-dev mailing list
>> lttng-dev at lists.lttng.org
>> http://lists.lttng.org/cgi-bin/mailman/listinfo/lttng-dev

--
Eugene Ivanov


________________________________

This e-mail is confidential and may contain legally privileged information. It is intended only for the addressees. If you have received this e-mail in error, kindly notify us immediately by telephone or e-mail and delete the message from your system.