Date: Wed, 6 Aug 2003 06:25:09 +0800 From: David Xu <davidxu@FreeBSD.org> To: Julian Elischer <julian@elischer.org>, Marcel Moolenaar <marcel@xcllnt.net> Cc: threads@FreeBSD.org Subject: Re: Good news: KSE on ia64 is starting to work Message-ID: <200308060625.09817.davidxu@FreeBSD.org> In-Reply-To: <Pine.BSF.4.21.0308051013210.82100-100000@InterJet.elischer.org> References: <Pine.BSF.4.21.0308051013210.82100-100000@InterJet.elischer.org>
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On Wednesday 06 August 2003 01:22, Julian Elischer wrote: > On Tue, 5 Aug 2003, Marcel Moolenaar wrote: > > Ok, > > > > I have a couple of changes and fixes in my tree that makes KSE on > > ia64 work. I have a couple of questions before I can commit it: > > On ia64 the TP will point to the TDB, as the spec says. > > there is only one case where this negatively impacts > libKSE and that is where the thread is setting itself into a critical > region. > > in i386 it is > > movl #0, %gs(offset) (clear a value in the KCB) > > which can be done atomically > since on ia64 TP points to teh THREAD structure, > we have a second method of setting a critical region which is inthe TCB > instead of being in the KCB, because > > using pdp11 syntax, > offset(TCB)->reg > NULL -> offset2(reg) > > cannot be done atomically and pre-emption may result in teh thread > switching KSEs between teh two instructions. > So on ia64 the critical region is defined as being enterred when > the alternative flag in the TCB is used.. > > David and Dan have more info and patches > I had committed a patch for kernel, the patch introduces a TMF_NOUPCALL flag which can be used for ia64 and alpha in libkse. I think Dan can commit his libkse patch now. David Xu
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