From mboxrd@z Thu Jan 1 00:00:00 1970 From: mans@mansr.com (=?iso-8859-1?Q?M=E5ns_Rullg=E5rd?=) Date: Fri, 27 Jan 2012 13:47:01 +0000 Subject: oprofile and ARM A9 hardware counter In-Reply-To: <20120127132826.GD2347@mudshark.cambridge.arm.com> (Will Deacon's message of "Fri, 27 Jan 2012 13:28:26 +0000") References: <20120127121311.GB2347@mudshark.cambridge.arm.com> <20120127132826.GD2347@mudshark.cambridge.arm.com> Message-ID: To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Will Deacon writes: > 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. This was with the Linaro tilt-3.2 kernel from git://git.linaro.org/landing-teams/working/ti/kernel.git, commit 73e2c294444f209d281f7cd10b52b53b087e74f1. Maybe one of the many patches it has on top of 3.2 is to blame. -- M?ns Rullg?rd mans at mansr.com