From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7F8D1C433F5 for ; Wed, 5 Jan 2022 11:26:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239679AbiAEL0H (ORCPT ); Wed, 5 Jan 2022 06:26:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56548 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239665AbiAEL0F (ORCPT ); Wed, 5 Jan 2022 06:26:05 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 019D2C061761; Wed, 5 Jan 2022 03:26:05 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id A3DE5B81A5F; Wed, 5 Jan 2022 11:26:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0AE60C36AEB; Wed, 5 Jan 2022 11:25:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641381962; bh=p7ARozmpHvdBcT5Sr9I/4lpUUJk42PlcQIdWxwnken8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=f085ntndt8wl1xZbURfzaE4LBumsXRrBAOzVzTWwKQUPQIzjxy1HKaK9h+S2ume8G D7qitRy09jLdWFQ6oaz0VVniaWFsa3ynQ2176GyOoePj2cYVMoLGIm9JRka0bUgn5f 9wmuAr0/HkdiWrzcz03ztA02HKm1i42tNYb6qnJHUcIVJIMLE/y8KHgGrxUW248RTV uPJUzeWm7ghp7fKTc7oPDnqBer3UVc5uDolxzyaOKEeDfpM/V1lAhOW3ZUdQ9L8btR 96Jcmc1htW1mypF5aS4jnDOfVfWE5v7bvtaLygOcX+xY963g+uxEneJbI/B+ZZsjfL UOdhbMn+SSVzA== Date: Wed, 5 Jan 2022 11:25:55 +0000 From: Will Deacon To: Geert Uytterhoeven Cc: Rob Herring , Mark Rutland , Peter Zijlstra , Vince Weaver , Jonathan Corbet , Catalin Marinas , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Borislav Petkov , the arch/x86 maintainers , "H. Peter Anvin" , Linux Kernel Mailing List , Linux ARM , linux-perf-users@vger.kernel.org, Linux-Renesas Subject: Re: [PATCH v13 3/5] arm64: perf: Add userspace counter access disable switch Message-ID: <20220105112555.GA3113@willie-the-truck> References: <20211208201124.310740-1-robh@kernel.org> <20211208201124.310740-4-robh@kernel.org> <20220104135658.GC1827@willie-the-truck> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220104135658.GC1827@willie-the-truck> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 04, 2022 at 01:56:59PM +0000, Will Deacon wrote: > On Tue, Dec 28, 2021 at 12:07:02PM +0100, Geert Uytterhoeven wrote: > > On Wed, Dec 8, 2021 at 9:19 PM Rob Herring wrote: > > > Like x86, some users may want to disable userspace PMU counter > > > altogether. Add a sysctl 'perf_user_access' file to control userspace > > > counter access. The default is '0' which is disabled. Writing '1' > > > enables access. > > > > > > Note that x86 supports globally enabling user access by writing '2' to > > > /sys/bus/event_source/devices/cpu/rdpmc. As there's not existing > > > userspace support to worry about, this shouldn't be necessary for Arm. > > > It could be added later if the need arises. > > > > Thanks for your patch, which is now commit e2012600810c9ded ("arm64: > > perf: Add userspace counter access disable switch") in arm64/for-next/core. > > > > This is causing two issues on Renesas Salvator-XS with R-Car H3. > > One during kernel boot: > > > > hw perfevents: enabled with armv8_cortex_a53 PMU driver, 7 > > counters available > > +sysctl duplicate entry: /kernel//perf_user_access > > +CPU: 0 PID: 1 Comm: swapper/0 Not tainted > > 5.16.0-rc3-arm64-renesas-00003-ge2012600810c #1420 > > +Hardware name: Renesas Salvator-X 2nd version board based on r8a77951 (DT) > > +Call trace: > > + dump_backtrace+0x0/0x190 > > + show_stack+0x14/0x20 > > + dump_stack_lvl+0x88/0xb0 > > + dump_stack+0x14/0x2c > > + __register_sysctl_table+0x384/0x818 > > + register_sysctl+0x20/0x28 > > + armv8_pmu_init.constprop.0+0x118/0x150 > > + armv8_a57_pmu_init+0x1c/0x28 > > + arm_pmu_device_probe+0x1b4/0x558 > > + armv8_pmu_device_probe+0x18/0x20 > > + platform_probe+0x64/0xd0 > > + really_probe+0xb4/0x2f8 > > + __driver_probe_device+0x74/0xd8 > > + driver_probe_device+0x3c/0xe0 > > + __driver_attach+0x80/0x110 > > + bus_for_each_dev+0x6c/0xc0 > > + driver_attach+0x20/0x28 > > + bus_add_driver+0x138/0x1e0 > > + driver_register+0x60/0x110 > > + __platform_driver_register+0x24/0x30 > > + armv8_pmu_driver_init+0x18/0x20 > > + do_one_initcall+0x15c/0x31c > > + kernel_init_freeable+0x2f0/0x354 > > + kernel_init+0x20/0x120 > > + ret_from_fork+0x10/0x20 > > hw perfevents: enabled with armv8_cortex_a57 PMU driver, 7 > > counters available > > > > Presumably the same entry is added twice, once for the A53 PMU, > > and a second time for the A57 PMU? > > Looks like it, and perhaps that's also what is confusing systemd? > Rob -- how come you didn't see this during your testing? > > Anywho, please can you try the untested diff below? I just remembered I have a big/little SoC on my desk after borrowing a NanoPi (RK3399) from Marc Z, so I took this diff for a spin there and both the kernel and systemd seem happy. Will From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D986AC433F5 for ; Wed, 5 Jan 2022 11:27:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=weZiqrQN5wkSNlTcxfJoB5U1PwNqowPXj+XRIZyAbO0=; b=KlixJyuvVMId9u tgsMHl6hFMBxge3T+01F4LQBp7SGLfZtZFDg9217hRtjKFqe4CCSIdYBCHkBcGhgIa2ethY7c3Gdf CEJAYCdxzjaDi4CpbfAe+1gHOgF3rV88353vi76LSK5jhT7rma+bY+H3Ic5vMpG6pXNKIiyZ9HHMV cGtzQRabZYIwCmPxtK5t1mdIRgpQCKwCdmUOn5pqBK4dVkKJrG8GtI7yAw+02onlkYND17AH86K7s g0MZnINFymWkoA9laTc6lA7Rhvzpfza/5OWEjYpz9zCiX4RnhrFCRtXc028ACVKv4IAHk2jRvJ4hM lV8FX5VQjyWphhFz9DfQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1n54Qp-00Ef8n-1i; Wed, 05 Jan 2022 11:26:15 +0000 Received: from ams.source.kernel.org ([2604:1380:4601:e00::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1n54Qe-00Ef4r-UQ for linux-arm-kernel@lists.infradead.org; Wed, 05 Jan 2022 11:26:06 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 9E304B81A5C; Wed, 5 Jan 2022 11:26:03 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0AE60C36AEB; Wed, 5 Jan 2022 11:25:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1641381962; bh=p7ARozmpHvdBcT5Sr9I/4lpUUJk42PlcQIdWxwnken8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=f085ntndt8wl1xZbURfzaE4LBumsXRrBAOzVzTWwKQUPQIzjxy1HKaK9h+S2ume8G D7qitRy09jLdWFQ6oaz0VVniaWFsa3ynQ2176GyOoePj2cYVMoLGIm9JRka0bUgn5f 9wmuAr0/HkdiWrzcz03ztA02HKm1i42tNYb6qnJHUcIVJIMLE/y8KHgGrxUW248RTV uPJUzeWm7ghp7fKTc7oPDnqBer3UVc5uDolxzyaOKEeDfpM/V1lAhOW3ZUdQ9L8btR 96Jcmc1htW1mypF5aS4jnDOfVfWE5v7bvtaLygOcX+xY963g+uxEneJbI/B+ZZsjfL UOdhbMn+SSVzA== Date: Wed, 5 Jan 2022 11:25:55 +0000 From: Will Deacon To: Geert Uytterhoeven Cc: Rob Herring , Mark Rutland , Peter Zijlstra , Vince Weaver , Jonathan Corbet , Catalin Marinas , Ingo Molnar , Arnaldo Carvalho de Melo , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Thomas Gleixner , Borislav Petkov , the arch/x86 maintainers , "H. Peter Anvin" , Linux Kernel Mailing List , Linux ARM , linux-perf-users@vger.kernel.org, Linux-Renesas Subject: Re: [PATCH v13 3/5] arm64: perf: Add userspace counter access disable switch Message-ID: <20220105112555.GA3113@willie-the-truck> References: <20211208201124.310740-1-robh@kernel.org> <20211208201124.310740-4-robh@kernel.org> <20220104135658.GC1827@willie-the-truck> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220104135658.GC1827@willie-the-truck> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220105_032605_336673_0B072892 X-CRM114-Status: GOOD ( 28.76 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Jan 04, 2022 at 01:56:59PM +0000, Will Deacon wrote: > On Tue, Dec 28, 2021 at 12:07:02PM +0100, Geert Uytterhoeven wrote: > > On Wed, Dec 8, 2021 at 9:19 PM Rob Herring wrote: > > > Like x86, some users may want to disable userspace PMU counter > > > altogether. Add a sysctl 'perf_user_access' file to control userspace > > > counter access. The default is '0' which is disabled. Writing '1' > > > enables access. > > > > > > Note that x86 supports globally enabling user access by writing '2' to > > > /sys/bus/event_source/devices/cpu/rdpmc. As there's not existing > > > userspace support to worry about, this shouldn't be necessary for Arm. > > > It could be added later if the need arises. > > > > Thanks for your patch, which is now commit e2012600810c9ded ("arm64: > > perf: Add userspace counter access disable switch") in arm64/for-next/core. > > > > This is causing two issues on Renesas Salvator-XS with R-Car H3. > > One during kernel boot: > > > > hw perfevents: enabled with armv8_cortex_a53 PMU driver, 7 > > counters available > > +sysctl duplicate entry: /kernel//perf_user_access > > +CPU: 0 PID: 1 Comm: swapper/0 Not tainted > > 5.16.0-rc3-arm64-renesas-00003-ge2012600810c #1420 > > +Hardware name: Renesas Salvator-X 2nd version board based on r8a77951 (DT) > > +Call trace: > > + dump_backtrace+0x0/0x190 > > + show_stack+0x14/0x20 > > + dump_stack_lvl+0x88/0xb0 > > + dump_stack+0x14/0x2c > > + __register_sysctl_table+0x384/0x818 > > + register_sysctl+0x20/0x28 > > + armv8_pmu_init.constprop.0+0x118/0x150 > > + armv8_a57_pmu_init+0x1c/0x28 > > + arm_pmu_device_probe+0x1b4/0x558 > > + armv8_pmu_device_probe+0x18/0x20 > > + platform_probe+0x64/0xd0 > > + really_probe+0xb4/0x2f8 > > + __driver_probe_device+0x74/0xd8 > > + driver_probe_device+0x3c/0xe0 > > + __driver_attach+0x80/0x110 > > + bus_for_each_dev+0x6c/0xc0 > > + driver_attach+0x20/0x28 > > + bus_add_driver+0x138/0x1e0 > > + driver_register+0x60/0x110 > > + __platform_driver_register+0x24/0x30 > > + armv8_pmu_driver_init+0x18/0x20 > > + do_one_initcall+0x15c/0x31c > > + kernel_init_freeable+0x2f0/0x354 > > + kernel_init+0x20/0x120 > > + ret_from_fork+0x10/0x20 > > hw perfevents: enabled with armv8_cortex_a57 PMU driver, 7 > > counters available > > > > Presumably the same entry is added twice, once for the A53 PMU, > > and a second time for the A57 PMU? > > Looks like it, and perhaps that's also what is confusing systemd? > Rob -- how come you didn't see this during your testing? > > Anywho, please can you try the untested diff below? I just remembered I have a big/little SoC on my desk after borrowing a NanoPi (RK3399) from Marc Z, so I took this diff for a spin there and both the kernel and systemd seem happy. Will _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel