Re: Remove or weaken hints about "effective resolution of sleep delays is 10 ms"? - Mailing list pgsql-hackers

From Merlin Moncure
Subject Re: Remove or weaken hints about "effective resolution of sleep delays is 10 ms"?
Date
Msg-id CAHyXU0zibW2iPrt6YgUT4Kv0Z5qvf+OpBVOUi4tNR_iP11Utgw@mail.gmail.com
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In response to Remove or weaken hints about "effective resolution of sleep delays is 10 ms"?  (Andres Freund <andres@anarazel.de>)
Responses Re: Remove or weaken hints about "effective resolution of sleep delays is 10 ms"?
List pgsql-hackers
On Wed, Feb 10, 2016 at 4:15 PM, Andres Freund <andres@anarazel.de> wrote:
> Hi,
>
> Several places in our docs have blurbs like
>> Note that on many systems, the effective resolution of sleep delays is
>> 10 milliseconds; setting <varname>wal_writer_delay</> to a value that
>> is not a multiple of 10 might have the same results as setting it to
>> the next higher multiple of 10.
> Afaik that's not the case on any recent operating system/hardware. So
> perhaps we should just remove all of those blurbs, or just replace them
> with something like "on some older systems the effective resolution of
> sleep delays is limited to multiples of 10 milliseconds"?

I guess we should probably explain what is actually happening, namely
that the precise sleep duration is delegated to the operating system
scheduler which may cause the process to sleep longer than requested.

merlin



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