From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57020) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dPc7k-0007h9-H9 for qemu-devel@nongnu.org; Mon, 26 Jun 2017 18:04:50 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dPc7h-0005Mu-Az for qemu-devel@nongnu.org; Mon, 26 Jun 2017 18:04:48 -0400 Received: from out3-smtp.messagingengine.com ([66.111.4.27]:39167) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dPc7h-0005M7-0B for qemu-devel@nongnu.org; Mon, 26 Jun 2017 18:04:45 -0400 From: "Emilio G. Cota" Date: Mon, 26 Jun 2017 18:04:36 -0400 Message-Id: <1498514681-3059-3-git-send-email-cota@braap.org> In-Reply-To: <1498514681-3059-1-git-send-email-cota@braap.org> References: <1498514681-3059-1-git-send-email-cota@braap.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Subject: [Qemu-devel] [PATCH 2/7] cpu: allocate cpu->trace_dstate in place List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: "Daniel P . Berrange" , =?UTF-8?q?Llu=C3=ADs=20Vilanova?= , Stefan Hajnoczi , Richard Henderson , Laurent Desnogues There's little point in dynamically allocating the bitmap if we know at compile-time the max number of events we want to support. Thus, make room in the struct for the bitmap, which will make things easier later: this paves the way for upcoming changes, in which we'll use a u32 to fully capture cpu->trace_dstate. This change also increases performance by saving a dereference and improving locality--note that this is important since upcoming work makes reading this bitmap fairly common. Reviewed-by: Lluís Vilanova Signed-off-by: Emilio G. Cota --- include/qom/cpu.h | 9 +++------ qom/cpu.c | 8 -------- trace/control.c | 9 ++++++++- 3 files changed, 11 insertions(+), 15 deletions(-) diff --git a/include/qom/cpu.h b/include/qom/cpu.h index 89ddb68..bc6e20f 100644 --- a/include/qom/cpu.h +++ b/include/qom/cpu.h @@ -259,6 +259,7 @@ typedef void (*run_on_cpu_func)(CPUState *cpu, run_on_cpu_data data); struct qemu_work_item; #define CPU_UNSET_NUMA_NODE_ID -1 +#define CPU_TRACE_DSTATE_MAX_EVENTS 32 /** * CPUState: @@ -373,12 +374,8 @@ struct CPUState { struct KVMState *kvm_state; struct kvm_run *kvm_run; - /* - * Used for events with 'vcpu' and *without* the 'disabled' properties. - * Dynamically allocated based on bitmap requried to hold up to - * trace_get_vcpu_event_count() entries. - */ - unsigned long *trace_dstate; + /* Used for events with 'vcpu' and *without* the 'disabled' properties */ + DECLARE_BITMAP(trace_dstate, CPU_TRACE_DSTATE_MAX_EVENTS); /* TODO Move common fields from CPUArchState here. */ int cpu_index; /* used by alpha TCG */ diff --git a/qom/cpu.c b/qom/cpu.c index 5069876..69fbb9c 100644 --- a/qom/cpu.c +++ b/qom/cpu.c @@ -382,7 +382,6 @@ static void cpu_common_unrealizefn(DeviceState *dev, Error **errp) static void cpu_common_initfn(Object *obj) { - uint32_t count; CPUState *cpu = CPU(obj); CPUClass *cc = CPU_GET_CLASS(obj); @@ -397,18 +396,11 @@ static void cpu_common_initfn(Object *obj) QTAILQ_INIT(&cpu->breakpoints); QTAILQ_INIT(&cpu->watchpoints); - count = trace_get_vcpu_event_count(); - if (count) { - cpu->trace_dstate = bitmap_new(count); - } - cpu_exec_initfn(cpu); } static void cpu_common_finalize(Object *obj) { - CPUState *cpu = CPU(obj); - g_free(cpu->trace_dstate); } static int64_t cpu_common_get_arch_id(CPUState *cpu) diff --git a/trace/control.c b/trace/control.c index 9b157b0..83740aa 100644 --- a/trace/control.c +++ b/trace/control.c @@ -65,8 +65,15 @@ void trace_event_register_group(TraceEvent **events) size_t i; for (i = 0; events[i] != NULL; i++) { events[i]->id = next_id++; - if (events[i]->vcpu_id != TRACE_VCPU_EVENT_NONE) { + if (events[i]->vcpu_id == TRACE_VCPU_EVENT_NONE) { + continue; + } + + if (likely(next_vcpu_id < CPU_TRACE_DSTATE_MAX_EVENTS)) { events[i]->vcpu_id = next_vcpu_id++; + } else { + error_report("WARNING: too many vcpu trace events; dropping '%s'", + events[i]->name); } } event_groups = g_renew(TraceEventGroup, event_groups, nevent_groups + 1); -- 2.7.4