From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 18581 invoked by alias); 6 Aug 2015 15:17:06 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 18570 invoked by uid 89); 6 Aug 2015 15:17:05 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.4 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=no version=3.3.2 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Thu, 06 Aug 2015 15:17:03 +0000 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (Postfix) with ESMTPS id 53AFFFA9F4; Thu, 6 Aug 2015 15:17:02 +0000 (UTC) Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t76FH0Bh002837; Thu, 6 Aug 2015 11:17:01 -0400 Message-ID: <55C37A6C.6050907@redhat.com> Date: Thu, 06 Aug 2015 15:17:00 -0000 From: Pedro Alves User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 MIME-Version: 1.0 To: "Metzger, Markus T" CC: "gdb-patches@sourceware.org" Subject: Re: [PATCH] configure: check for perf_event.h version References: <1438866405-22616-1-git-send-email-markus.t.metzger@intel.com> <55C365B2.4010906@redhat.com> <55C36F31.5080807@redhat.com> In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2015-08/txt/msg00156.txt.bz2 On 08/06/2015 04:00 PM, Metzger, Markus T wrote: >> -----Original Message----- >> From: Pedro Alves [mailto:palves@redhat.com] >> Sent: Thursday, August 6, 2015 4:29 PM >> To: Metzger, Markus T >> Cc: gdb-patches@sourceware.org >> Subject: Re: [PATCH] configure: check for perf_event.h version >> >> On 08/06/2015 03:14 PM, Metzger, Markus T wrote: >>>> -----Original Message----- >>>> From: Pedro Alves [mailto:palves@redhat.com] >>>> Sent: Thursday, August 6, 2015 3:49 PM >>>> To: Metzger, Markus T >>>> Cc: gdb-patches@sourceware.org >>>> Subject: Re: [PATCH] configure: check for perf_event.h version >>>> >>>> On 08/06/2015 02:06 PM, Markus Metzger wrote: >>>>> Intel(R) Processor Trace support requires a recent linux/perf_event.h >>>> header. >>>>> >>>>> When GDB is built on an older system, Intel(R) Processor Trace will not >> be >>>>> available and there is no indication in the configure and build log as to >>>>> what went wrong. >>>>> >>>>> Check for a compatible linux/perf_event.h at configure-time. >>>> >>>> >>>>> diff --git a/gdb/configure.ac b/gdb/configure.ac >>>>> index 905c27b..d867e85 100644 >>>>> --- a/gdb/configure.ac >>>>> +++ b/gdb/configure.ac >>>>> @@ -1252,6 +1252,20 @@ if test "${with_intel_pt}" = no; then >>>>> AC_MSG_WARN([Intel(R) Processor Trace support disabled; some >>>> features may be unavailable.]) >>>>> HAVE_LIBIPT=no >>>>> else >>>>> + AC_PREPROC_IFELSE(AC_LANG_SOURCE([[ >>>>> +#include >>>>> +#ifdef PERF_ATTR_SIZE_VER5 >>>>> +# error >>>>> +#endif >>>> >>>> Can you explain what kind of symbol PERF_ATTR_SIZE_VER5 is? >>>> From the patch, I understand that that is something that is _not_ >>>> defined in the perf versions that are supposedly supported? >>>> (otherwise, I'd expect an #ifndef instead.) >>> >>> It's a macro. >> >> Was there ever a PERF_ATTR_SIZE_VER4 symbol? What if >> PERF_ATTR_SIZE_VER6 is ever created? Do we want to have to >> check for it explicitly then? > > The linux/perf_event.h header defines the macros for all previous > versions. The current version thus defines > > #define PERF_ATTR_SIZE_VER0 64 /* sizeof first published struct */ > #define PERF_ATTR_SIZE_VER1 72 /* add: config2 */ > #define PERF_ATTR_SIZE_VER2 80 /* add: branch_sample_type */ > #define PERF_ATTR_SIZE_VER3 96 /* add: sample_regs_user */ > /* add: sample_stack_user */ > #define PERF_ATTR_SIZE_VER4 104 /* add: sample_regs_intr */ > #define PERF_ATTR_SIZE_VER5 112 /* add: aux_watermark */ Ah. Thanks. Thanks, Pedro Alves