lkml.org 
[lkml]   [2022]   [Sep]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    Date
    SubjectRe: [PATCH v5 06/18] rcu: Introduce call_rcu_lazy() API implementation
    From


    On 9/7/2022 6:03 AM, Frederic Weisbecker wrote:
    > On Tue, Sep 06, 2022 at 12:15:19PM -0400, Joel Fernandes wrote:
    >>>> +
    >>>> + // We had CBs in the bypass list before. There is nothing else to do if:
    >>>> + // There were only non-lazy CBs before, in this case, the bypass timer
    >>>
    >>> Kind of misleading. I would replace "There were only non-lazy CBs before" with
    >>> "There was at least one non-lazy CBs before".
    >>
    >> I really mean "There were only non-lazy CBs ever queued in the bypass list
    >> before". That's the bypass_is_lazy variable. So I did not fully understand your
    >> suggested comment change.
    >
    > I may well be missing something but to me it seems that:
    >
    > bypass_is_lazy = all bypass callbacks are lazy
    > !bypass_is_lazy = there is at least one non-lazy bypass callback
    >
    > And indeed as long as there is at least one non-lazy callback, we don't
    > want to rely on the LAZY timer.
    >
    > Am I overlooking something?

    No you are not over looking and you are very right that I may need to change the
    comment.

    To clarify my intent, a wake up or timer adjustment needs to be done only if:

    1. Bypass list was fully empty before (this is the first bypass list entry).

    Or both the below conditions are met:

    1. Bypass list had only lazy CBs before.

    2. The new CB is non-lazy.

    Instead of saying, "nothing needs to be done if...", I will change it to:

    // A wake up of the grace period kthread or timer adjustment needs to
    // be done only if:
    // 1. Bypass list was empty before (this is the first bypass queue).
    // Or, both the below conditions are met:
    // 1. Bypass list had only lazy CBs before.
    // 2. The new CB is non-lazy.

    That sounds less confusing...

    Or, I can just make the edit you suggested... let me know either way!

    Thanks!

    - Joel

    \
     
     \ /
      Last update: 2022-09-07 16:01    [W:3.325 / U:0.016 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site