From harmony-dev-return-17776-apmail-incubator-harmony-dev-archive=incubator.apache.org@incubator.apache.org Wed Nov 01 08:20:59 2006 Return-Path: Delivered-To: apmail-incubator-harmony-dev-archive@www.apache.org Received: (qmail 96538 invoked from network); 1 Nov 2006 08:20:58 -0000 Received: from hermes.apache.org (HELO mail.apache.org) (140.211.11.2) by minotaur.apache.org with SMTP; 1 Nov 2006 08:20:58 -0000 Received: (qmail 37655 invoked by uid 500); 1 Nov 2006 08:21:06 -0000 Delivered-To: apmail-incubator-harmony-dev-archive@incubator.apache.org Received: (qmail 37624 invoked by uid 500); 1 Nov 2006 08:21:05 -0000 Mailing-List: contact harmony-dev-help@incubator.apache.org; run by ezmlm Precedence: bulk List-Help: List-Unsubscribe: List-Post: List-Id: Reply-To: harmony-dev@incubator.apache.org Delivered-To: mailing list harmony-dev@incubator.apache.org Received: (qmail 37615 invoked by uid 99); 1 Nov 2006 08:21:05 -0000 Received: from herse.apache.org (HELO herse.apache.org) (140.211.11.133) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 01 Nov 2006 00:21:05 -0800 X-ASF-Spam-Status: No, hits=2.5 required=10.0 tests=DNS_FROM_RFC_ABUSE,HTML_MESSAGE,SPF_PASS X-Spam-Check-By: apache.org Received-SPF: pass (herse.apache.org: domain of mike.fursov@gmail.com designates 64.233.182.184 as permitted sender) Received: from [64.233.182.184] (HELO nf-out-0910.google.com) (64.233.182.184) by apache.org (qpsmtpd/0.29) with ESMTP; Wed, 01 Nov 2006 00:20:52 -0800 Received: by nf-out-0910.google.com with SMTP id m18so578240nfc for ; Wed, 01 Nov 2006 00:20:31 -0800 (PST) DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=beta; d=gmail.com; h=received:message-id:date:from:to:subject:in-reply-to:mime-version:content-type:references; b=djyALvCwQASbC7axLEXBVa0gqs1kQ9D2YYRTLpFKEI4wJa/kBtixqI0w1SlBYPUnifZynNP+yxROk7JuGTYoBv6JlBP5gbygZ1YaHPipsbB2pH+zbQrEoj8lEQPQBLL42Lo6jP4EG6z5RIZdLs6Qj6RuHELNrfUllE3VzxgOEm8= Received: by 10.78.204.1 with SMTP id b1mr8457045hug; Wed, 01 Nov 2006 00:20:31 -0800 (PST) Received: by 10.78.182.4 with HTTP; Wed, 1 Nov 2006 00:20:30 -0800 (PST) Message-ID: Date: Wed, 1 Nov 2006 14:20:30 +0600 From: "Mikhail Fursov" To: harmony-dev@incubator.apache.org Subject: Re: [drlvm][sablevm] Desing of Class Unloading Support In-Reply-To: <51d555c70610311454s24d2089cx7eeb9af17d7ebfaf@mail.gmail.com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_15361_14215536.1162369230967" References: <5836de490610240251p120dfa56x736fbb5eb1898aca@mail.gmail.com> <12385bbd0610291051l4a23f64h8f726e1103a4bc59@mail.gmail.com> <45450269.4020503@sablevm.org> <4dd1f3f00610291553x5d7b2bc9seb2c419bd4fa54ff@mail.gmail.com> <45461100.50304@sablevm.org> <51d555c70610301610qf3f2c67g35899c9bbc6a4d3d@mail.gmail.com> <4547A6E4.5080903@sablevm.org> <12385bbd0610311259m1012cdadl4f9452dc336dbac7@mail.gmail.com> <4547BC2B.2080600@sablevm.org> <51d555c70610311454s24d2089cx7eeb9af17d7ebfaf@mail.gmail.com> X-Virus-Checked: Checked by ClamAV on apache.org ------=_Part_15361_14215536.1162369230967 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline On 11/1/06, Rana Dasgupta wrote: > > Maybe for GC's that don't support pinning, the JIT can compare > object->vtable->class for guarded > devirtiualization, or even not do guarded devirtualization, sort of > support > the GC in downlevel mode I think this is not a long term solution for a JIT. IMO the best solutions for a JIT with unpinned vtables would be 1) Short term: turn devirtualization off (As Egor has proposed) 2) Long term: patch devirtualization calls when GC moves object (usual enumeration routine) Storing vtable in the object without additional indirection in memory is important from the performance POV. -- Mikhail Fursov ------=_Part_15361_14215536.1162369230967--