Re: Question about list_sort() RCU version.

[Mathieu Desnoyers <mathieu.desnoyers@efficios.com>]

----- On Jun 16, 2020, at 4:17 PM, Chaitanya Kulkarni Chaitanya.Kulkarni@wdc.com wrote:

> Hi RCU maintainers and experts,
> 
> I'm working on a linux kernel upstream project which is in the tree.
> With the POC I can already see that significant performance improvement
> with RCU in the fast path which are replacing rw semaphore, but not
> having list_sort() rcu variant is blocking the developement and getting
> code upstream.

Why do you need list_sort() ? Is there any way you could simply insert your
new elements into the list in already-sorted order ? This would ensure that
the list is always in a sorted state, which I suspect will be expected by
RCU readers.

Thanks,

Mathieu


> 
> I was not able to find the such helper implemented for the RCU flavor of
> list.
> 
> Can someone provide information about :-
> 
> 1. Is there any plan to have list_sort_rcu() ? if so when can we expect
>    that ? (Also how can I help ?)
> 
> 2. In case there is no plan what are design considerations if someone
>    wants to implement the code and submit it upstream ?
>    (Also how can I help here ?
-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com