>-----Original Message----- >From: Andrew Morton [mailto:[EMAIL PROTECTED] >Subject: Re: [Discuss][i386] Platform SMIs and their >interferance with tsc based delay calibration > > >Please don't send emails which contain 500-column lines?
Sorry. Something got messed up during cut and paste onto my mailer. >> Solution: >> The patch below makes the calibration routine aware of >asynchronous events >> like SMIs. We increase the delay calibration time and also >identify any >> significant errors (greater than 12.5%) in the calibration >and notify it >> to user. Like to know your comments on this. > >I find calibrate_delay_tsc() quite confusing. Are you sure that the >variable names are correct? > > + tsc_rate_max = (post_end - pre_start) / DELAY_CALIBRATION_TICKS; > + tsc_rate_min = (pre_end - post_start) / DELAY_CALIBRATION_TICKS; > >that looks strange. I'm sure it all makes sense if one understands the >algorithm, but it shouldn't be this hard. Please reissue the >patch with >adequate comments which describe what the code is doing. > I will resend the patch soon with more comments. I think the variable names here are bit confusing. >Shouldn't calibrate_delay_tsc() be __devinit? (That may >generate warnings >from reference_discarded.pl, but they're false positives) > > >From a maintainability POV it's not good that x86 is no longer >using the >generic calibrate_delay() code. Can you rework the code so that all >architectures must implement arch_calibrate_delay(), then >provide stubs for >all except x86? After all, other architectures/platforms may >have the same >problem. > Agreed. I will add a stub in other architectures. That way we don't have to duplicate the current delay_calibration under i386. Thanks, Venki - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
