From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stas Sergeev Subject: Re: freezes when not emulating CPU Date: Fri, 18 Sep 2009 01:05:11 +0400 Message-ID: <4AB2A487.2060205@aknet.ru> References: <4AAA2D35.3040309@aknet.ru> <4AAE6090.5030603@aknet.ru> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-msdos-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii"; format="flowed" To: Samuel Bronson Cc: Bart Oldeman , dosemu 18.09.2009 00:37, Samuel Bronson wrote: > Well, I believe that's essentially what Intel suggests OSes do on > task-switch -- leave some flag set/cleared that will cause the next FP > operation to give an exception so that it can switch the FP registers > at that time. Whether or not this would be a good idea for DOSEMU > depends on how often you do a vm86 call vs how often the FP registers > are needed, and on how expensive it is to actually enter a state from > which the next FP access will cause a signal compared to just doing > the reload each time. dosemu is not interrupted by the DOS code, so the full reload is never really needed. You just need the "known good state", rather than the "full previous state". If whatever is needed is only fninit/ldmxcsr, then I guess it is just cool.