From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ozlabs.org (ozlabs.org [IPv6:2401:3900:2:1::2]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id BA1811A0CDD for ; Thu, 24 Dec 2015 03:12:35 +1100 (AEDT) Received: from smtprelay.hostedemail.com (smtprelay0118.hostedemail.com [216.40.44.118]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id C9C45140C04 for ; Thu, 24 Dec 2015 03:12:34 +1100 (AEDT) Date: Wed, 23 Dec 2015 11:12:28 -0500 From: Steven Rostedt To: Denis Kirjanov Cc: Michael Ellerman , linuxppc-dev@ozlabs.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 2/2] powerpc: tracing: don't trace hcalls on offline CPUs Message-ID: <20151223111228.10f25239@gandalf.local.home> In-Reply-To: <1450124286-4822-2-git-send-email-kda@linux-powerpc.org> References: <1450124286-4822-1-git-send-email-kda@linux-powerpc.org> <1450124286-4822-2-git-send-email-kda@linux-powerpc.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Mon, 14 Dec 2015 23:18:06 +0300 Denis Kirjanov wrote: > ./drmgr -c cpu -a -r gives the following warning: > > [ 2327.035563] > RCU used illegally from offline CPU! > rcu_scheduler_active = 1, debug_locks = 1 > [ 2327.035564] no locks held by swapper/12/0. > [ 2327.035565] > stack backtrace: > [ 2327.035567] CPU: 12 PID: 0 Comm: swapper/12 Tainted: G S > 4.3.0-rc3-00060-g353169a #5 > [ 2327.035568] Call Trace: > [ 2327.035573] [c0000001d62578e0] [c0000000008977fc] .dump_stack+0x98/0xd4 (unreliable) > [ 2327.035577] [c0000001d6257960] [c000000000109bd8] .lockdep_rcu_suspicious+0x108/0x170 > [ 2327.035580] [c0000001d62579f0] [c00000000006a1d0] .__trace_hcall_exit+0x2b0/0x2c0 > [ 2327.035584] [c0000001d6257ab0] [c00000000006a2e8] plpar_hcall_norets_trace+0x70/0x8c > [ 2327.035588] [c0000001d6257b20] [c000000000067a14] .icp_hv_set_cpu_priority+0x54/0xc0 > [ 2327.035592] [c0000001d6257ba0] [c000000000066c5c] .xics_teardown_cpu+0x5c/0xa0 > [ 2327.035595] [c0000001d6257c20] [c0000000000747ac] .pseries_mach_cpu_die+0x6c/0x320 > [ 2327.035598] [c0000001d6257cd0] [c0000000000439cc] .cpu_die+0x3c/0x60 > [ 2327.035602] [c0000001d6257d40] [c0000000000183d8] .arch_cpu_idle_dead+0x28/0x40 > [ 2327.035606] [c0000001d6257db0] [c0000000000ff1dc] .cpu_startup_entry+0x4fc/0x560 > [ 2327.035610] [c0000001d6257ed0] [c000000000043728] .start_secondary+0x328/0x360 > [ 2327.035614] [c0000001d6257f90] [c000000000008a6c] start_secondary_prolog+0x10/0x14 > [ 2327.035620] cpu 12 (hwid 12) Ready to die... > [ 2327.144463] cpu 13 (hwid 13) Ready to die... > [ 2327.294180] cpu 14 (hwid 14) Ready to die... > [ 2327.403599] cpu 15 (hwid 15) Ready to die... > > Make the hypervisor tracepoints conditional > by using TRACE_EVENT_FN_COND > > Signed-off-by: Denis Kirjanov I applied the first patch, but I need Acks from the powerpc maintainers to take this one. -- Steve > > v2 changes: > - Use raw_smp_processor_id as suggested by BenH > since since hcalls can be called from preemptable sections > > v3 changes: > - Fix the subject line > --- > arch/powerpc/include/asm/trace.h | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/arch/powerpc/include/asm/trace.h b/arch/powerpc/include/asm/trace.h > index 8e86b48..32e36b1 100644 > --- a/arch/powerpc/include/asm/trace.h > +++ b/arch/powerpc/include/asm/trace.h > @@ -57,12 +57,14 @@ DEFINE_EVENT(ppc64_interrupt_class, timer_interrupt_exit, > extern void hcall_tracepoint_regfunc(void); > extern void hcall_tracepoint_unregfunc(void); > > -TRACE_EVENT_FN(hcall_entry, > +TRACE_EVENT_FN_COND(hcall_entry, > > TP_PROTO(unsigned long opcode, unsigned long *args), > > TP_ARGS(opcode, args), > > + TP_CONDITION(cpu_online(raw_smp_processor_id())), > + > TP_STRUCT__entry( > __field(unsigned long, opcode) > ), > @@ -76,13 +78,15 @@ TRACE_EVENT_FN(hcall_entry, > hcall_tracepoint_regfunc, hcall_tracepoint_unregfunc > ); > > -TRACE_EVENT_FN(hcall_exit, > +TRACE_EVENT_FN_COND(hcall_exit, > > TP_PROTO(unsigned long opcode, unsigned long retval, > unsigned long *retbuf), > > TP_ARGS(opcode, retval, retbuf), > > + TP_CONDITION(cpu_online(raw_smp_processor_id())), > + > TP_STRUCT__entry( > __field(unsigned long, opcode) > __field(unsigned long, retval)