From: Andi Kleen Subject: Re: [PATCH v5 07/12] perf/x86: no counter allocation support Date: Thu, 14 Feb 2019 08:26:13 -0800 Message-ID: <20190214162613.GK16922@tassilo.jf.intel.com> References: <1550135174-5423-1-git-send-email-wei.w.wang@intel.com> <1550135174-5423-8-git-send-email-wei.w.wang@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, pbonzini@redhat.com, peterz@infradead.org, kan.liang@intel.com, mingo@redhat.com, rkrcmar@redhat.com, like.xu@intel.com, jannh@google.com, arei.gonglei@huawei.com, jmattson@google.com To: Wei Wang Return-path: Content-Disposition: inline In-Reply-To: <1550135174-5423-8-git-send-email-wei.w.wang@intel.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org > diff --git a/include/uapi/linux/perf_event.h b/include/uapi/linux/perf_event.h > index 9de8780..ec97a70 100644 > --- a/include/uapi/linux/perf_event.h > +++ b/include/uapi/linux/perf_event.h > @@ -372,7 +372,8 @@ struct perf_event_attr { > context_switch : 1, /* context switch data */ > write_backward : 1, /* Write ring buffer from end to beginning */ > namespaces : 1, /* include namespaces data */ > - __reserved_1 : 35; > + no_counter : 1, /* no counter allocation */ Not sure we really want to expose this in the user ABI. Perhaps make it a feature of the in kernel API only? -Andi