From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 8418C8D36 for ; Mon, 26 Sep 2016 17:43:39 +0200 (CEST) Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 0D4333DEEB; Mon, 26 Sep 2016 15:43:39 +0000 (UTC) Received: from dhcp-25-97.bos.redhat.com (dhcp-25-172.bos.redhat.com [10.18.25.172]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u8QFhbUF004512 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Mon, 26 Sep 2016 11:43:38 -0400 From: Aaron Conole To: Flavio Leitner Cc: dpdk References: <1474642051-9973-1-git-send-email-fbl@sysclose.org> Date: Mon, 26 Sep 2016 11:43:37 -0400 In-Reply-To: <1474642051-9973-1-git-send-email-fbl@sysclose.org> (Flavio Leitner's message of "Fri, 23 Sep 2016 11:47:31 -0300") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.68 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.29]); Mon, 26 Sep 2016 15:43:39 +0000 (UTC) Subject: Re: [dpdk-dev] [PATCH] eal: check cpu flags at init X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 26 Sep 2016 15:43:40 -0000 Flavio Leitner writes: > An application might be linked to DPDK but not really use it, > so move the cpu flag check to the EAL initialization instead. > > Signed-off-by: Flavio Leitner > --- > lib/librte_eal/bsdapp/eal/eal.c | 3 +++ > lib/librte_eal/common/eal_common_cpuflags.c | 6 ------ > lib/librte_eal/linuxapp/eal/eal.c | 3 +++ > 3 files changed, 6 insertions(+), 6 deletions(-) > > diff --git a/lib/librte_eal/bsdapp/eal/eal.c b/lib/librte_eal/bsdapp/eal/eal.c > index a0c8f8c..c4b22af 100644 > --- a/lib/librte_eal/bsdapp/eal/eal.c > +++ b/lib/librte_eal/bsdapp/eal/eal.c > @@ -496,6 +496,9 @@ rte_eal_init(int argc, char **argv) > char cpuset[RTE_CPU_AFFINITY_STR_LEN]; > char thread_name[RTE_MAX_THREAD_NAME_LEN]; > > + /* checks if the machine is adequate */ > + rte_cpu_check_supported(); > + I think it makes sense to return a result here; after all, since this is no longer a *constructor*, we can actually handle a failure case. So maybe the following diff: diff --git a/lib/librte_eal/common/eal_common_cpuflags.c b/lib/librte_eal/common/eal_common_cpuflags.c index ecb1240..eccf5f8 100644 --- a/lib/librte_eal/common/eal_common_cpuflags.c +++ b/lib/librte_eal/common/eal_common_cpuflags.c @@ -38,15 +38,9 @@ /** * Checks if the machine is adequate for running the binary. If it is not, the - * program exits with status 1. - * The function attribute forces this function to be called before main(). But - * with ICC, the check is generated by the compiler. + * function returns ENOTSUP. */ -#ifndef __INTEL_COMPILER -void __attribute__ ((__constructor__)) -#else -void -#endif +int rte_cpu_check_supported(void) { /* This is generated at compile-time by the build system */ @@ -63,14 +57,15 @@ rte_cpu_check_supported(void) fprintf(stderr, "ERROR: CPU feature flag lookup failed with error %d\n", ret); - exit(1); + return ENOTSUP; } if (!ret) { fprintf(stderr, "ERROR: This system does not support \"%s\".\n" "Please check that RTE_MACHINE is set correctly.\n", rte_cpu_get_flag_name(compile_time_flags[i])); - exit(1); + return ENOTSUP; } } + return 0; } diff --git a/lib/librte_eal/common/include/generic/rte_cpuflags.h b/lib/librte_eal/common/include/generic/rte_cpuflags.h index 71321f3..6e4eb5a 100644 --- a/lib/librte_eal/common/include/generic/rte_cpuflags.h +++ b/lib/librte_eal/common/include/generic/rte_cpuflags.h @@ -79,7 +79,7 @@ rte_cpu_get_flag_enabled(enum rte_cpu_flag_t feature); * that were specified at compile time. It is called automatically within the * EAL, so does not need to be used by applications. */ -void +int rte_cpu_check_supported(void); #endif /* _RTE_CPUFLAGS_H_ */ -- and the change these hunks to: if (!rte_cpu_check_supported()) { return -1; } My only concern is whether this change would be considered ABI breaking. I wouldn't think so, since it doesn't seem as though an application would want to call this explicitly (and is spelled out as such), but I can't be sure that it isn't already included in the standard application API, and therefore needs to go through the change process. My $.02 -Aaron > if (!rte_atomic32_test_and_set(&run_once)) > return -1; > > diff --git a/lib/librte_eal/common/eal_common_cpuflags.c b/lib/librte_eal/common/eal_common_cpuflags.c > index ecb1240..b5f76f7 100644 > --- a/lib/librte_eal/common/eal_common_cpuflags.c > +++ b/lib/librte_eal/common/eal_common_cpuflags.c > @@ -39,14 +39,8 @@ > /** > * Checks if the machine is adequate for running the binary. If it is not, the > * program exits with status 1. > - * The function attribute forces this function to be called before main(). But > - * with ICC, the check is generated by the compiler. > */ > -#ifndef __INTEL_COMPILER > -void __attribute__ ((__constructor__)) > -#else > void > -#endif > rte_cpu_check_supported(void) > { > /* This is generated at compile-time by the build system */ > diff --git a/lib/librte_eal/linuxapp/eal/eal.c b/lib/librte_eal/linuxapp/eal/eal.c > index d5b81a3..4e88cfc 100644 > --- a/lib/librte_eal/linuxapp/eal/eal.c > +++ b/lib/librte_eal/linuxapp/eal/eal.c > @@ -740,6 +740,9 @@ rte_eal_init(int argc, char **argv) > char cpuset[RTE_CPU_AFFINITY_STR_LEN]; > char thread_name[RTE_MAX_THREAD_NAME_LEN]; > > + /* checks if the machine is adequate */ > + rte_cpu_check_supported(); > + > if (!rte_atomic32_test_and_set(&run_once)) > return -1;