> -----Original Message----- > From: linux-omap-owner@xxxxxxxxxxxxxxx [mailto:linux-omap- > owner@xxxxxxxxxxxxxxx] On Behalf Of Siarhei Siamashka > Sent: 2010-04-01 21:02 > To: G, Manjunath Kondaiah; Koskinen Aaro (Nokia-D/Helsinki) > Cc: linux-omap@xxxxxxxxxxxxxxx; DebBarma, Tarun Kanti > Subject: Re: [PATCH] OMAP GPTimer for OProfile(Errata#628216) > > On Thursday 01 April 2010 18:24:08 ext Manjunatha GK wrote: > > From: DebBarma, Tarun Kanti <tarun.kanti@xxxxxx> > > > > [ARM Cortex-A8 Errata 628216] > > If a Perf Counter OVFL occurs simultaneously with an update to a CP14 or > > CP15 register, the OVFL status can be lost. > > > > In order to workaround problem in Cortex-A8 Performance Counter, OMAP > > GPTIMER is used by OProfile. > > Thanks for digging this up. But even though GPTIMER has a lower overhead, > there is actually a better (more portable) fix which is on the way into > mainline kernel: > http://marc.info/?l=oprofile-list&m=126754919315010&w=2 > > Samples collection frequency can be adjusted by another patch (the default > 128Hz used on most ARM boards/devices is way too low). > > oprofile kernel module can be loaded with 'timer=1' parameter to override > the use of buggy Cortex-A8 PMU. [Ghorai] ok. Your patch did not work if I build inside kernel image. Here is the error - $>opcontrol --setup --vmlinux=/vmlinux cpu_type 'unset' is not valid you should upgrade oprofile or force the use of timer mode /usr/bin/objdump > > -- > Best regards, > Siarhei Siamashka > -- > 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 -- 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
