RFR(M): 8166970: Adapt mutex padding according to DEFAULT_CACHE_LINE_SIZE

[Thomas Stüfe]

Hi Martin,

you do not have to do the subclassing just to find out the size of all
members preceding _name. Just use offsetof():

CACHE_LINE_PADDING = DEFAULT_CACHE_LINE_SIZE - offsetof(_name)

...Kind Regards, Thomas


On Fri, Sep 30, 2016 at 5:48 PM, Doerr, Martin <martin.doerr at sap.com> wrote:

> Hi,
>
> the current implementation of Monitor padding (mutex.cpp) assumes that
> cache lines are 64 Bytes. There's a platform dependent define
> "DEFAULT_CACHE_LINE_SIZE" available which can be used. Purpose of padding
> is to avoid false sharing.
>
> My proposed change is here:
> http://cr.openjdk.java.net/~mdoerr/8166970_mutex_padding/webrev.00/
>
> Please review. If will also need a sponsor.
>
> Thanks and best regards,
> Martin
>
>