From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Galbraith Subject: [rt-patch 1/3] arm64/acpi/perf: move pmu allocation to an early CPU up hook Date: Sat, 28 Jul 2018 11:13:55 +0200 Message-ID: <1532769235.5926.0.camel@gmx.de> References: <20180727215710.zq6gkoqzlb4ca7qv@linutronix.de> <1532768831.9882.71.camel@gmx.de> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-15" Content-Transfer-Encoding: 7bit Cc: LKML , linux-rt-users , Steven Rostedt To: Sebastian Andrzej Siewior , Thomas Gleixner Return-path: In-Reply-To: <1532768831.9882.71.camel@gmx.de> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-rt-users.vger.kernel.org RT cannot allocate while irqs are disabled. BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:974 in_atomic(): 0, irqs_disabled(): 128, pid: 25, name: cpuhp/0 CPU: 0 PID: 25 Comm: cpuhp/0 Not tainted 4.16.18-rt10-rt #2 Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.32 08/22/2017 Call trace: dump_backtrace+0x0/0x188 show_stack+0x24/0x30 dump_stack+0x9c/0xd0 ___might_sleep+0x124/0x188 rt_spin_lock+0x40/0x80 pcpu_alloc+0x104/0x7a0 __alloc_percpu_gfp+0x38/0x48 __armpmu_alloc+0x44/0x168 armpmu_alloc_atomic+0x1c/0x28 arm_pmu_acpi_cpu_starting+0x1cc/0x210 cpuhp_invoke_callback+0xb8/0x820 cpuhp_thread_fun+0xc0/0x1e0 smpboot_thread_fn+0x1ac/0x2c8 kthread+0x134/0x138 ret_from_fork+0x10/0x18 Move the allocation to CPUHP_BP_PREPARE_DYN, where we'll be preemptible, thus no longer needing GFP_ATOMIC. Signed-off-by: Mike Galbraith --- drivers/perf/arm_pmu_acpi.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/perf/arm_pmu_acpi.c +++ b/drivers/perf/arm_pmu_acpi.c @@ -135,10 +135,10 @@ static struct arm_pmu *arm_pmu_acpi_find return pmu; } - pmu = armpmu_alloc_atomic(); + pmu = armpmu_alloc(); if (!pmu) { pr_warn("Unable to allocate PMU for CPU%d\n", - smp_processor_id()); + raw_smp_processor_id()); return NULL; } @@ -283,7 +283,7 @@ static int arm_pmu_acpi_init(void) if (ret) return ret; - ret = cpuhp_setup_state(CPUHP_AP_PERF_ARM_ACPI_STARTING, + ret = cpuhp_setup_state(CPUHP_BP_PREPARE_DYN, "perf/arm/pmu_acpi:starting", arm_pmu_acpi_cpu_starting, NULL);