From owner-freebsd-threads@FreeBSD.ORG Fri Jul 18 16:47:31 2003 Return-Path: Delivered-To: freebsd-threads@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 6566E37B401; Fri, 18 Jul 2003 16:47:31 -0700 (PDT) Received: from rwcrmhc11.comcast.net (rwcrmhc11.comcast.net [204.127.198.35]) by mx1.FreeBSD.org (Postfix) with ESMTP id E272C43FA3; Fri, 18 Jul 2003 16:47:30 -0700 (PDT) (envelope-from julian@elischer.org) Received: from interjet.elischer.org ([12.233.125.100]) by attbi.com (rwcrmhc11) with ESMTP id <2003071823473001300mf83se>; Fri, 18 Jul 2003 23:47:30 +0000 Received: from localhost (localhost.elischer.org [127.0.0.1]) by InterJet.elischer.org (8.9.1a/8.9.1) with ESMTP id QAA16427; Fri, 18 Jul 2003 16:47:23 -0700 (PDT) Date: Fri, 18 Jul 2003 16:47:22 -0700 (PDT) From: Julian Elischer To: deischen@freebsd.org In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII cc: threads@freebsd.org cc: Marcel Moolenaar Subject: Re: Rearranging kse mailbox X-BeenThere: freebsd-threads@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Threading on FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 18 Jul 2003 23:47:31 -0000 On Fri, 18 Jul 2003, Daniel Eischen wrote: > On Fri, 18 Jul 2003, Marcel Moolenaar wrote: > > > On Fri, Jul 18, 2003 at 03:08:40PM -0700, Julian Elischer wrote: > > > > > > the ia64 requires that the thread pointer points to > > > aome location that is 16 bytes long, the first 8 bytes > > > of which is a pointer to the TLS Dynamic thread vector, and the 2nd 8 > > > bytes is application specific, but in practice, must be a pointer to > > > the Thread's or KSE's mailbox (I guess KSE to be similar to the others.) > > > > > > ia32 requires just that the thread control info pointed to by %gs > > > SOMEWHERE contains a pointer to the dtv (where SOMEWHERE is a known > > > offset). (In our case the offset would be 0) > > > > > > This means that for the UTS to find the active thread under ia64 > > > takes an extra level of indirection. (node neither of these > > > affect upcalls as teh UTS upcall target function has the mailbox as an > > > argument and can access it independently of %gs or the tp. > > > > > > Am I right that "variant 2" (as seen in the ia32 case) > > > applies to allarchitectures other than ia64? > > > > That is what I need to find out. If the runtime specification has > > a register dedicated for TLS, like on ia64, it will likely behave > > more like ia64 than ia32. I think the amd64 runtime is new enough > > for it to be like ia64. > > The amd64 also has a %gs which is used for this. Only the > kernel can set it, though, so I think it needs to be per-KSE. > > > Note that the extra level of indirection on ia64 can be avoided if > > we put the thread control structure at a negative offset from TP. > > The layout would be something like: > > > > -... 0 8 16 ...+ > > [thread structure][DTV pointer][free][static TLS] > > ^ > > TP > > Can we make this work so that we are not limited to > 8192 (or whatever max user LDTs are) threads on i386? he's talking ia64.. > > -- > Dan Eischen > >