> -----Original Message----- > From: Premi, Sanjeev > Sent: Friday, June 24, 2011 7:24 PM > To: linux-omap@xxxxxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx > Cc: Premi, Sanjeev > Subject: [PATCHv2] omap2+: pm: cpufreq: Fix loops_per_jiffy > calculation > > Currently, loops_per_jiffy is being calculated twice for > non-SMP processors. > - Before calling cpufreq_notify_transition() > - From within cpufreq_notify_transition() > > Double adjustment leads to incorrect value being assigned to > loops_per_jiffy. This manifests as incorrect BogoMIPS in > "cat /proc/cpuinfo". > > The value of loops_per_jiffy needs to be calculated only > when CONFIG_SMP is true. It is the core change included > in this patch. > > The patch also leverages the definition of for_each_cpu() > with and without CONFIG_SMP to consolidate the mechanism > to call cpufreq_notify_transition(). > > Signed-off-by: Sanjeev Premi <premi@xxxxxx> > --- > Changes since v1: > * loops_per_jiffy are updated when CONFIG_SMP is true. > * leverage definition of for_each_cpu() > > Tested on OMAP3EVM with and without CONFIG_SMP. > Since the log is rather long, will be posting the log in > a follow-up mail. > [snip]...[snip] Snapshot of test log - with and without SMP included here: To ensure compile-time and run-time checks for SMP are visible, the patch was tested with this code inserted at enty of function omap_target(). #ifdef CONFIG_SMP printk (KERN_ERR "I am defined SMP!\n"); #else printk (KERN_ERR "I am not defined SMP!\n"); #endif if (is_smp()) printk (KERN_ERR "Runtime evaluating to SMP!\n"); else printk (KERN_ERR "Runtime evaluating to no SMP!\n"); With CONFIG_SMP disabled ======================== [root@OMAP3EVM /]# cd /sys/devices/system/cpu/cpu0/cpufreq/ [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# cat scaling_available_frequencies 300000 600000 800000 1000000 [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# echo 300000 > scaling_setspeed [ 56.278137] I am not defined SMP! [ 56.281768] Runtime evaluating to no SMP! [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# cat cpuinfo_cur_freq 300000 [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# cat /proc/cpuinfo Processor : ARMv7 Processor rev 2 (v7l) BogoMIPS : 298.32 Features : swp half thumb fastmult vfp edsp thumbee neon vfpv3 CPU implementer : 0x41 CPU architecture: 7 CPU variant : 0x3 CPU part : 0xc08 CPU revision : 2 Hardware : OMAP3 EVM Revision : 0020 Serial : 0000000000000000 [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# echo 800000 > scaling_setspeed [ 96.938049] I am not defined SMP! [ 96.941833] Runtime evaluating to no SMP! [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# cat /proc/cpuinfo Processor : ARMv7 Processor rev 2 (v7l) BogoMIPS : 796.19 Features : swp half thumb fastmult vfp edsp thumbee neon vfpv3 CPU implementer : 0x41 CPU architecture: 7 CPU variant : 0x3 CPU part : 0xc08 CPU revision : 2 Hardware : OMAP3 EVM Revision : 0020 Serial : 0000000000000000 [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# echo 100000 > scaling_setspeed [ 110.865631] I am not defined SMP! [ 110.870025] Runtime evaluating to no SMP! [root@OMAP3EVM cpufreq]# echo 1000000 > scaling_setspeed [ 116.258941] I am not defined SMP! [ 116.262725] Runtime evaluating to no SMP! [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# cat cpuinfo_cur_freq 1000000 [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# cat /proc/cpuinfo Processor : ARMv7 Processor rev 2 (v7l) BogoMIPS : 996.74 Features : swp half thumb fastmult vfp edsp thumbee neon vfpv3 CPU implementer : 0x41 CPU architecture: 7 CPU variant : 0x3 CPU part : 0xc08 CPU revision : 2 Hardware : OMAP3 EVM Revision : 0020 Serial : 0000000000000000 [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# With CONFIG_SMP enabled ======================== [root@OMAP3EVM /]# cd /sys/devices/system/cpu/cpu0/cpufreq/ [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# cat scaling_available_frequencies 300000 600000 800000 1000000 [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# echo 300000 > scaling_setspeed [ 25.040496] I am defined SMP! [ 25.043884] Runtime evaluating to no SMP! [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# cat /proc/cpuinfo Processor : ARMv7 Processor rev 2 (v7l) processor : 0 BogoMIPS : 298.32 Features : swp half thumb fastmult vfp edsp thumbee neon vfpv3 CPU implementer : 0x41 CPU architecture: 7 CPU variant : 0x3 CPU part : 0xc08 CPU revision : 2 Hardware : OMAP3 EVM Revision : 0020 Serial : 0000000000000000 [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# cat cpuinfo_cur_freq 300000 [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# echo 800000 > scaling_setspeed [ 46.333618] I am defined SMP! [ 46.336822] Runtime evaluating to no SMP! [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# cat cpuinfo_cur_freq 800000 [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# cat /proc/cpuinfo Processor : ARMv7 Processor rev 2 (v7l) processor : 0 BogoMIPS : 796.19 Features : swp half thumb fastmult vfp edsp thumbee neon vfpv3 CPU implementer : 0x41 CPU architecture: 7 CPU variant : 0x3 CPU part : 0xc08 CPU revision : 2 Hardware : OMAP3 EVM Revision : 0020 Serial : 0000000000000000 [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# echo 600000 > scaling_setspeed [ 1344.705413] I am defined SMP! [ 1344.709259] Runtime evaluating to no SMP! [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# [root@OMAP3EVM cpufreq]# cat /proc/cpuinfo Processor : ARMv7 Processor rev 2 (v7l) processor : 0 BogoMIPS : 597.64 Features : swp half thumb fastmult vfp edsp thumbee neon vfpv3 CPU implementer : 0x41 CPU architecture: 7 CPU variant : 0x3 CPU part : 0xc08 CPU revision : 2 Hardware : OMAP3 EVM Revision : 0020 Serial : 0000000000000000 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
