From ec756d45b7f21888f4b44cb71b047e33ee2c8d8f Mon Sep 17 00:00:00 2001 From: Yang Wei Date: Tue, 5 Aug 2014 13:37:47 +0800 Subject: [PATCH] MIPS: perf: Mark pmu interupt IRQF_NO_THREAD In RT kernel, I ran into the following calltrace, so PMU interrupts cannot be threaded in_atomic(): 1, irqs_disabled(): 1, pid: 0, name: swapper/0 INFO: lockdep is turned off. Call Trace: [] dump_stack+0x1c/0x50 [] __might_sleep+0x13c/0x148 [] rt_spin_lock+0x3c/0xb0 [] __wake_up+0x3c/0x80 [] perf_event_wakeup+0x8c/0xf8 [] perf_pending_event+0x40/0x78 [] irq_work_run+0x74/0xc0 [] mipsxx_pmu_handle_shared_irq+0x110/0x228 [] mipsxx_pmu_handle_irq+0x14/0x30 [] handle_irq_event_percpu+0xbc/0x470 [] handle_percpu_irq+0x98/0xc8 [] generic_handle_irq+0x4c/0x68 [] do_IRQ+0x2c/0x48 [] plat_irq_dispatch+0x64/0xd0 [ralf@linux-mips.org: I don't see why based on this register dump the handler should be marked IRQF_NO_THREAD - but the handler is manipulating per-CPU resources so we don't want it to be rescheduled to another CPU.] Signed-off-by: Yang Wei Cc: a.p.zijlstra@chello.nl Cc: paulus@samba.org Cc: mingo@redhat.com Cc: acme@kernel.org Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/7506/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/perf_event_mipsxx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/mips/kernel/perf_event_mipsxx.c b/arch/mips/kernel/perf_event_mipsxx.c index 14bf74b..b63f248 100644 --- a/arch/mips/kernel/perf_event_mipsxx.c +++ b/arch/mips/kernel/perf_event_mipsxx.c @@ -558,7 +558,7 @@ static int mipspmu_get_irq(void) if (mipspmu.irq >= 0) { /* Request my own irq handler. */ err = request_irq(mipspmu.irq, mipsxx_pmu_handle_irq, - IRQF_PERCPU | IRQF_NOBALANCING, + IRQF_PERCPU | IRQF_NOBALANCING | IRQF_NO_THREAD, "mips_perf_pmu", NULL); if (err) { pr_warning("Unable to request IRQ%d for MIPS " -- 2.7.4