From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Mosberger Date: Thu, 10 Jan 2002 23:37:17 +0000 Subject: RE: [Linux-ia64] [PATCH] Support for alternative kernel profiler Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-ia64@vger.kernel.org >>>>> On Thu, 10 Jan 2002 15:26:58 -0800, "Luck, Tony" said: Tony> We don't currently have any way for different software Tony> packages to share the performance counters, so it's very Tony> likely that there would be interactions with Stephane's PMU Tony> code (e.g. I rewrite cr.pmv to a new vector and re-write all Tony> of the pmc[] and pmd[] registers for my own purposes ... this Tony> will upset Stephane's code, similarly my code does not expect Tony> anyone else to touch any PMU registers, or fiddle with Tony> psr.pp/dcr.pp). Tony> It would probably be safest to turn off CONFIG_PERFMON in a Tony> kernel that is going to load an alternate profiler ... my Tony> profiler seems to cope ok provided nobody calls Tony> sys_perfmonctl(). This hardly seems like an ideal solution. If you just want to keep your patch for yourself, that's probably OK, but if it is to become part of the kernel, we should look into a way for safely sharing the PMU. The first obvious way to try is to do the profiling you want on top of perfmon. --david