Do you think we should try for an implementation that restarts the APs each time in the first pass implementation? [Jeff] I think software semaphore is acceptable solution now. My former question is to confirm if there is any issue if sending IPI.
Jeff -----Original Message----- From: Jordan Justen [mailto:[email protected]] Sent: Friday, September 12, 2014 8:01 AM To: Fan, Jeff Cc: Chen Fan; [email protected] Subject: Re: [RFC v2 00/15] Introduce Mp Service protocol to UefiCpuPkg On Thu, Sep 11, 2014 at 12:36 AM, Fan, Jeff <[email protected]> wrote: > I added my comments in [Jeff]. I think quoting works better. Oh well... > -----Original Message----- > From: Jordan Justen [mailto:[email protected]] > Sent: Thursday, September 11, 2014 3:21 PM > To: Fan, Jeff > Cc: Chen Fan; [email protected] > Subject: Re: [RFC v2 00/15] Introduce Mp Service protocol to > UefiCpuPkg > > On Wed, Sep 10, 2014 at 11:56 PM, Fan, Jeff <[email protected]> wrote: >> Why did you get rid of sending IPI to wake up APs? Do you encounter any >> issue with it? >> From your patch, I don't know why StarupThisAP () cannot work correctly. >> Could you send me your AP routine test code and test procedure? > > I think that a startup IPI is used once, but not again after the APs have > been woken once. At least, that was my feedback previously. > [Jeff] We observed that polling a semaphore in memory for all APs may lead > the bad boot performance on real platform. So, normally we place APs in one > hlt-loop and sending start IPI to wake up them. > Sure, semaphore is also one of our methods to wake up AP. This is good information. I only asked Chen to start this way because it should be simpler for the first pass implementation. I figured a restart process might need to be added to cover a case of an AP that gets stuck. Do you think we should try for an implementation that restarts the APs each time in the first pass implementation? Thanks, -Jordan ------------------------------------------------------------------------------ Want excitement? Manually upgrade your production database. When you want reliability, choose Perforce Perforce version control. Predictably reliable. http://pubads.g.doubleclick.net/gampad/clk?id=157508191&iu=/4140/ostg.clktrk _______________________________________________ edk2-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/edk2-devel
