harmony-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Xiao-Feng Li" <xiaofeng...@gmail.com>
Subject Re: [jira] Commented: (HARMONY-5399) [drlvm][jit] Enabling arraycopy optimization for primitive types when write barriers are enabled
Date Fri, 18 Jan 2008 10:33:08 GMT
On 18 Jan 2008 12:52:28 +0300, Egor Pasko <egor.pasko@gmail.com> wrote:
> On the 0x3CF day of Apache Harmony Xiao-Feng Li wrote:
> > On Jan 18, 2008 2:30 PM, George Timoshenko (JIRA) <jira@apache.org> wrote:
> > >
> > >     [ https://issues.apache.org/jira/browse/HARMONY-5399?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12560243#action_12560243
]
> > >
> > > George Timoshenko commented on HARMONY-5399:
> > > --------------------------------------------
> > >
> > > I have one consern.
> > >
> > > By the modification of "arraycopyOptimizable" you turn of the both
> > >
> > > genArrayCopy and
> > > genArrayCopyRepMove
> > >
> > > optimizations of the arrays of Object types.
> > >
> > > BUT the first one, genArrayCopy, does not use REP instruction. It generates
a copying loop so it can work with WB.
> >
> >
> > For array write, it's ok to have only one WB for the whole object. In
> > my current generational GC design, I use WB actually for object
> > remembering rather than slot remembering. So one WB for the whole
> > arraycopy is enough.
> >
> > (Well, write barrier support in DRLVM needs cleanup thenafter.)
>
> So, you are not planning to get WB for each object in the array in the
> nearest future? then we can stick to one WB per array for now before
> the cleanup happens, right?

Actually, I only want to ease the work by JIT team at the moment. The
real situation is, we need both slot remembering and object
remembering. They could be needed separately by different GCs, or they
could be used simultaneously by the same GC. This needs cleanup once
the current development wave is passed.

Thanks,
xiaofeng

> I would +1 then.
>
> P.S. hm, I thought you have several GC designs and experiment between
> them.. and some had WB per slot strategy..
>
> > Thanks,
> > xiaofeng
> >
> > >
> > > > [drlvm][jit] Enabling arraycopy optimization for primitive types when
write barriers are enabled
> > > > ------------------------------------------------------------------------------------------------
> > > >
> > > >                 Key: HARMONY-5399
> > > >                 URL: https://issues.apache.org/jira/browse/HARMONY-5399
> > > >             Project: Harmony
> > > >          Issue Type: Improvement
> > > >         Environment: All
> > > >            Reporter: Aleksey Shipilev
> > > >         Attachments: WB-2.patch, WB-3.patch, WB-4.patch
> > > >
> > > >
> > > > JIT arraycopy optimization is disabled automatically when WB are enabled.
Attached patch re-enables arraycopy optimization for arrays of primitive types, which shouldn't
interfere with WB activity.
> > >
> > > --
> > > This message is automatically generated by JIRA.
> > > -
> > > You can reply to this email to add a comment to the issue online.
> > >
> > >
> >
> >
> >
> > --
> > http://xiao-feng.blogspot.com
> >
>
> --
> Egor Pasko
>
>



-- 
http://xiao-feng.blogspot.com

Mime
View raw message