Date: Mon, 7 Jan 2002 11:34:19 -0700 From: Nate Williams <nate@yogotech.com> To: Dan Eischen <eischen@vigrid.com> Cc: Peter Wemm <peter@wemm.org>, Archie Cobbs <archie@dellroad.org>, Alfred Perlstein <bright@mu.org>, arch@FreeBSD.ORG Subject: Re: Request for review: getcontext, setcontext, etc Message-ID: <15417.59947.662052.836634@caddis.yogotech.com> In-Reply-To: <3C390746.5FE7648C@vigrid.com> References: <20020106232937.9F87D38CC@overcee.netplex.com.au> <3C390746.5FE7648C@vigrid.com>
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> > Also, I noticed that the i386 patch doesn't save FP state (!) which is > > one of the primary reasons for get/setcontext(). I'm not sure if this > > can be efficiently done since this user-level function will not know if > > the current context has touched the FPU yet.. > > Neither does the kernel, does it? I thought I saw comments in the > kernel (was it alpha?) about it being too bad that we couldn't tell > if the FPU was used. In libc_r, we currently only save and restore the > FP state when the context is generated from a signal handler (or perhaps > in the case of KSEs, when the thread was preempted). Hmm, IIRC, Java's green threads saves the FP context everytime it does a thread switch, since it has no way of knowing if the thread was doing FP context. Is there a way to force get/setcontext to always/conditionally save the FP context, for applications that either know they need to have it saved? Nate To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
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