[prev in list] [next in list] [prev in thread] [next in thread] 

List:       openjdk-hotspot-dev
Subject:    Re: RFR: 8192123: Zero should use compiler built-ins for atomics on linux-arm
From:       Andrew Haley <aph () redhat ! com>
Date:       2017-11-29 16:16:54
Message-ID: 84581646-0d6e-f709-1618-cdf3c5848546 () redhat ! com
[Download RAW message or body]

On 29/11/17 15:45, John Paul Adrian Glaubitz wrote:
> On 11/29/2017 04:39 PM, coleen.phillimore@oracle.com wrote:
>>> Hmm.  This doesn't fix a bug, and there's a non-zero probability of
>>> introducing one.  I guess it should be OK, but this is a combination
>>> of performance improvement (possibly) and cleanup.
>>>
>> Please save this change for JDK 11.
> 
> I just made the same obvious change as I did for m68k. Is there really
> a risk of introducing a regression?

There's always a risk with any change.  In this case, we know that the
kernel builtin is very stable, and we don't know that every version of
GCC will always use the kernel builtin.

> It only affects Zero after all which is not officially supported, is it?
> 
> The supported ARMv7 Server build is not affected as this change is
> below the linux_zero directory.

Yea, but there's still a risk, supported or not.  It can surely wait
until 11.

-- 
Andrew Haley
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671
[prev in list] [next in list] [prev in thread] [next in thread]