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
