Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932071AbaJUJOp (ORCPT ); Tue, 21 Oct 2014 05:14:45 -0400 Received: from casper.infradead.org ([85.118.1.10]:50402 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754803AbaJUJOk (ORCPT ); Tue, 21 Oct 2014 05:14:40 -0400 Date: Tue, 21 Oct 2014 11:14:34 +0200 From: Peter Zijlstra To: Hendrik Brueckner , Andy Lutomirski , Valdis Kletnieks , "linux-kernel@vger.kernel.org" , Paul Mackerras , Arnaldo Carvalho de Melo , Ingo Molnar , Kees Cook , Andrea Arcangeli , Erik Bosman , mpe@ellerman.id.au, anton@samba.org, schwidefsky@de.ibm.com Subject: Re: [RFC 5/5] x86,perf: Only allow rdpmc if a perf_event is mapped Message-ID: <20141021091434.GN23531@worktop.programming.kicks-ass.net> References: <20141019213534.GG23531@worktop.programming.kicks-ass.net> <20141020084813.GB3219@twins.programming.kicks-ass.net> <20141020105110.GA5002@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141020105110.GA5002@linux.vnet.ibm.com> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 20, 2014 at 12:51:10PM +0200, Hendrik Brueckner wrote: > I think it would makes sense to return 0 as default in the > perf_event_idx_default() and let each PMU/arch that actually supports > reading PMCs from user space return the proper index. And according > to tools/perf/design.txt, index must be non-zero to trigger a user space > read. OK, I've got something like the below. Michael/Anton, would you please clarify the ppc book3s capabilities? --- Subject: perf: Clean up pmu::event_idx From: Peter Zijlstra Date: Tue Oct 21 11:10:21 CEST 2014 Andy reported that the current state of event_idx is rather confused. So remove all but the x86_pmu implementation and change the default to return 0 (the safe option). Reported-by: Andy Lutomirski Signed-off-by: Peter Zijlstra (Intel) --- arch/powerpc/perf/hv-24x7.c | 6 ------ arch/powerpc/perf/hv-gpci.c | 6 ------ arch/s390/kernel/perf_cpum_sf.c | 6 ------ kernel/events/core.c | 15 +-------------- kernel/events/hw_breakpoint.c | 7 ------- 5 files changed, 1 insertion(+), 39 deletions(-) --- a/arch/powerpc/perf/hv-24x7.c +++ b/arch/powerpc/perf/hv-24x7.c @@ -417,11 +417,6 @@ static int h_24x7_event_add(struct perf_ return 0; } -static int h_24x7_event_idx(struct perf_event *event) -{ - return 0; -} - static struct pmu h_24x7_pmu = { .task_ctx_nr = perf_invalid_context, @@ -433,7 +428,6 @@ static struct pmu h_24x7_pmu = { .start = h_24x7_event_start, .stop = h_24x7_event_stop, .read = h_24x7_event_update, - .event_idx = h_24x7_event_idx, }; static int hv_24x7_init(void) --- a/arch/powerpc/perf/hv-gpci.c +++ b/arch/powerpc/perf/hv-gpci.c @@ -246,11 +246,6 @@ static int h_gpci_event_init(struct perf return 0; } -static int h_gpci_event_idx(struct perf_event *event) -{ - return 0; -} - static struct pmu h_gpci_pmu = { .task_ctx_nr = perf_invalid_context, @@ -262,7 +257,6 @@ static struct pmu h_gpci_pmu = { .start = h_gpci_event_start, .stop = h_gpci_event_stop, .read = h_gpci_event_update, - .event_idx = h_gpci_event_idx, }; static int hv_gpci_init(void) --- a/arch/s390/kernel/perf_cpum_sf.c +++ b/arch/s390/kernel/perf_cpum_sf.c @@ -1411,11 +1411,6 @@ static void cpumsf_pmu_del(struct perf_e perf_pmu_enable(event->pmu); } -static int cpumsf_pmu_event_idx(struct perf_event *event) -{ - return event->hw.idx; -} - CPUMF_EVENT_ATTR(SF, SF_CYCLES_BASIC, PERF_EVENT_CPUM_SF); CPUMF_EVENT_ATTR(SF, SF_CYCLES_BASIC_DIAG, PERF_EVENT_CPUM_SF_DIAG); @@ -1458,7 +1453,6 @@ static struct pmu cpumf_sampling = { .stop = cpumsf_pmu_stop, .read = cpumsf_pmu_read, - .event_idx = cpumsf_pmu_event_idx, .attr_groups = cpumsf_pmu_attr_groups, }; --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6071,11 +6071,6 @@ static int perf_swevent_init(struct perf return 0; } -static int perf_swevent_event_idx(struct perf_event *event) -{ - return 0; -} - static struct pmu perf_swevent = { .task_ctx_nr = perf_sw_context, @@ -6085,8 +6080,6 @@ static struct pmu perf_swevent = { .start = perf_swevent_start, .stop = perf_swevent_stop, .read = perf_swevent_read, - - .event_idx = perf_swevent_event_idx, }; #ifdef CONFIG_EVENT_TRACING @@ -6204,8 +6197,6 @@ static struct pmu perf_tracepoint = { .start = perf_swevent_start, .stop = perf_swevent_stop, .read = perf_swevent_read, - - .event_idx = perf_swevent_event_idx, }; static inline void perf_tp_register(void) @@ -6431,8 +6422,6 @@ static struct pmu perf_cpu_clock = { .start = cpu_clock_event_start, .stop = cpu_clock_event_stop, .read = cpu_clock_event_read, - - .event_idx = perf_swevent_event_idx, }; /* @@ -6511,8 +6500,6 @@ static struct pmu perf_task_clock = { .start = task_clock_event_start, .stop = task_clock_event_stop, .read = task_clock_event_read, - - .event_idx = perf_swevent_event_idx, }; static void perf_pmu_nop_void(struct pmu *pmu) @@ -6542,7 +6529,7 @@ static void perf_pmu_cancel_txn(struct p static int perf_event_idx_default(struct perf_event *event) { - return event->hw.idx + 1; + return 0; } /* --- a/kernel/events/hw_breakpoint.c +++ b/kernel/events/hw_breakpoint.c @@ -605,11 +605,6 @@ static void hw_breakpoint_stop(struct pe bp->hw.state = PERF_HES_STOPPED; } -static int hw_breakpoint_event_idx(struct perf_event *bp) -{ - return 0; -} - static struct pmu perf_breakpoint = { .task_ctx_nr = perf_sw_context, /* could eventually get its own */ @@ -619,8 +614,6 @@ static struct pmu perf_breakpoint = { .start = hw_breakpoint_start, .stop = hw_breakpoint_stop, .read = hw_breakpoint_pmu_read, - - .event_idx = hw_breakpoint_event_idx, }; int __init init_hw_breakpoint(void) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/