Yeah, you're right.
On Fri, Dec 19, 2008 at 9:26 AM, Ali Saidi <[email protected]> wrote: > For our initial purposes the default executes the halt instruction and > should suffice as long as we have an implementation of halt that > quiesces the CPU, correct? > > Ali > > > > On Dec 19, 2008, at 10:08, "nathan binkert" <[email protected]> wrote: > >> Gabe, if you have any further questions on the x86 idle loop, I'm >> actually quite familiar with it because of the ASISA stuff I was >> doing. Ali is correct in how the idle loop works. One thing that is >> nice is that the idle function is actually a function pointer, so it >> is designed to be swapped with a different function. That makes it >> really easy for you to write an m5 specific function and just change >> the function pointer. (I've for example changed the idle function by >> loading a module.) >> >> Nate >> >> On Fri, Dec 19, 2008 at 6:36 AM, Ali Saidi <[email protected]> wrote: >>> >>> >>> There are a couple of psuedo instructions, although I believe that >>> x86 >>> at least has one type built in. >>> Here are the alpha patches: >>> http://repo.m5sim.org/linux-patches/file/0ab58d9bd9a5/m5/quiesce.diff >>> http://repo.m5sim.org/linux-patches/file/0ab58d9bd9a5/m5/quiesce_2.6.27.diff >>> >>> I'm pretty sure cpu_idle() eventually calls delaut_idle() which calls >>> safe_halt(). I can't find a definition for it, however I would >>> imagine >>> it executes the halt instruction and the cpu is quiesced until an >>> interrupt arrives so diff #2 in the list is already implemented in >>> x86. >>> >>> Diff #1 still needs to be implemented. To make it boot faster you'll >>> need to modify arch/x86/lib/delay.c is a simlar manner to how I >>> modified the alpha version. For that version I ended up adding a >>> parameter nanoseconds to the delay_loop() function since the caller >>> knew the number of nanoseconds and the loop only knew the number of >>> jiffies. With the number of nano seconds I simply quiesce for the >>> number of ns requested and then immediately test for the number of ns >>> requested. If the time hasn't arrived yet, do some math and put the >>> processor back to sleep. >>> >>> Ali >>> >>> >>> >>> >>> >>> On Dec 19, 2008, at 7:38 AM, Geoffrey Blake wrote: >>> >>>> I'm pretty sure in the alpha linux code, that they've added the >>>> quiesce() >>>> pseudo-inst to just skip past any busy wait loops. They've done this >>>> for the >>>> cpu_idle() loop as well in Alpha. >>>> >>>> -----Original Message----- >>>> From: [email protected] [mailto:[email protected]] On >>>> Behalf >>>> Of Gabe Black >>>> Sent: Friday, December 19, 2008 3:50 AM >>>> To: M5 Developer List >>>> Subject: [m5-dev] SLOOOOOOOOOOW IDE controller >>>> >>>> I finally have the IDE controller sort of working (yay!), but >>>> apparently there's a built in 3 millisecond busy loop delay before >>>> the >>>> device is recognized as ready to go. In general, did you need to do >>>> anything special to make the controller start up and work in a >>>> reasonable amount of real time for Alpha? >>>> >>>> Gabe >>>> _______________________________________________ >>>> m5-dev mailing list >>>> [email protected] >>>> http://m5sim.org/mailman/listinfo/m5-dev >>>> >>>> >>>> >>>> No virus found in this incoming message. >>>> Checked by AVG - http://www.avg.com >>>> Version: 8.0.176 / Virus Database: 270.9.19/1856 - Release Date: >>>> 12/18/2008 >>>> 8:06 PM >>>> >>>> _______________________________________________ >>>> m5-dev mailing list >>>> [email protected] >>>> http://m5sim.org/mailman/listinfo/m5-dev >>>> >>> >>> _______________________________________________ >>> m5-dev mailing list >>> [email protected] >>> http://m5sim.org/mailman/listinfo/m5-dev >>> >>> >> _______________________________________________ >> m5-dev mailing list >> [email protected] >> http://m5sim.org/mailman/listinfo/m5-dev >> > _______________________________________________ > m5-dev mailing list > [email protected] > http://m5sim.org/mailman/listinfo/m5-dev > > _______________________________________________ m5-dev mailing list [email protected] http://m5sim.org/mailman/listinfo/m5-dev
