From mboxrd@z Thu Jan 1 00:00:00 1970 From: will.deacon@arm.com (Will Deacon) Date: Fri, 27 Jan 2012 13:28:26 +0000 Subject: oprofile and ARM A9 hardware counter In-Reply-To: References: <20120127121311.GB2347@mudshark.cambridge.arm.com> Message-ID: <20120127132826.GD2347@mudshark.cambridge.arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Mans, On Fri, Jan 27, 2012 at 12:56:35PM +0000, M?ns Rullg?rd wrote: > Will Deacon writes: > > Did this lead anywhere in the end? It seems as though Ming Lei has a working > > setup but Stephane is unable to replicate it, despite applying the necessary > > patches and trying an updated bootloader. > > With the patches listed above plus the one in [1], I get PMU interrupts. > However, unless I restrict the profiled process to one CPU > (taskset 1 perf record ...), I get a panic in armpmu_event_update() with > the 'event' argument being null when called from armv7pmu_handle_irq(). > > [1] http://article.gmane.org/gmane.linux.ports.arm.omap/69696 Great, thanks for trying this out. Which version of the kernel were you using? I fixed a bunch of NULL pointer derefs. during the 3.2 window, but if you were using an -rc kernel you have have hit one of them. Will