From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by dpdk.org (Postfix) with ESMTP id 85E3E4C8C; Mon, 5 Nov 2018 15:06:42 +0100 (CET) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga004.fm.intel.com ([10.253.24.48]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Nov 2018 06:06:41 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,468,1534834800"; d="scan'208";a="103534394" Received: from fmsmsx105.amr.corp.intel.com ([10.18.124.203]) by fmsmga004.fm.intel.com with ESMTP; 05 Nov 2018 06:06:41 -0800 Received: from fmsmsx115.amr.corp.intel.com (10.18.116.19) by FMSMSX105.amr.corp.intel.com (10.18.124.203) with Microsoft SMTP Server (TLS) id 14.3.408.0; Mon, 5 Nov 2018 06:06:41 -0800 Received: from fmsmsx117.amr.corp.intel.com ([169.254.3.70]) by fmsmsx115.amr.corp.intel.com ([169.254.4.121]) with mapi id 14.03.0415.000; Mon, 5 Nov 2018 06:06:40 -0800 From: "Wiles, Keith" To: Yongseok Koh CC: Thomas Monjalon , "Richardson, Bruce" , "Yigit, Ferruh" , "dev@dpdk.org" , Shahaf Shuler , "Ananyev, Konstantin" , "Burakov, Anatoly" , "stable@dpdk.org" Thread-Topic: [dpdk-dev] [PATCH v2] build: disable compiler AVX512F support Thread-Index: AQHUcu+vmWpd/xglbEqZ2Y8mm6wxz6VBwceA Date: Mon, 5 Nov 2018 14:06:39 +0000 Message-ID: <7879265D-9280-47ED-8987-A332C0A3DBF9@intel.com> References: <20181023212318.43082-1-yskoh@mellanox.com> <20181102210348.28148-1-yskoh@mellanox.com> In-Reply-To: <20181102210348.28148-1-yskoh@mellanox.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.252.8.114] Content-Type: text/plain; charset="us-ascii" Content-ID: <28562FF263AFF84A9A826C3E663147BB@intel.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH v2] build: disable compiler AVX512F support X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches for DPDK stable branches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 05 Nov 2018 14:06:43 -0000 > On Nov 2, 2018, at 9:04 PM, Yongseok Koh wrote: >=20 > This is a workaround to prevent a crash, which might be caused by > optimization of newer gcc (7.3.0) on Intel Skylake. Should the code below not also test for the gcc version and the Sky Lake pr= ocessor, maybe I am wrong but it seems it is turning AVX512 for all GCC bui= lds Also bug 97 seems a bit obscure reference, maybe you know the bug report, b= ut more details would be good? >=20 > Bugzilla ID: 97 >=20 > Cc: stable@dpdk.org >=20 > Signed-off-by: Yongseok Koh > --- >=20 > v2: > * disable the flag only in case of gcc >=20 > config/x86/meson.build | 5 +++++ > mk/rte.cpuflags.mk | 7 +++++++ > 2 files changed, 12 insertions(+) >=20 > diff --git a/config/x86/meson.build b/config/x86/meson.build > index 33efb5e547..8ddca0ea9f 100644 > --- a/config/x86/meson.build > +++ b/config/x86/meson.build > @@ -47,6 +47,11 @@ endif > if cc.get_define('__AVX512F__', args: march_opt) !=3D '' > dpdk_conf.set('RTE_MACHINE_CPUFLAG_AVX512F', 1) > compile_time_cpuflags +=3D ['RTE_CPUFLAG_AVX512F'] > +else > +# disable AVX512F support of gcc as a workaround for Bug 97 > + if cc.get_id() =3D=3D 'gcc' and cc.has_argument('-mavx512f') > + machine_args +=3D '-mno-avx512f' > + endif > endif >=20 > dpdk_conf.set('RTE_CACHE_LINE_SIZE', 64) > diff --git a/mk/rte.cpuflags.mk b/mk/rte.cpuflags.mk > index 43ed84155b..a8c26fb011 100644 > --- a/mk/rte.cpuflags.mk > +++ b/mk/rte.cpuflags.mk > @@ -68,6 +68,13 @@ endif > ifneq ($(filter $(AUTO_CPUFLAGS),__AVX512F__),) > ifeq ($(CONFIG_RTE_ENABLE_AVX512),y) > CPUFLAGS +=3D AVX512F > +else > +# disable AVX512F support of gcc as a workaround for Bug 97 > +ifeq ($(CONFIG_RTE_TOOLCHAIN_GCC),y) > + ifeq ($(shell $(CC) --target-help | grep -q mavx512f && echo 1), 1) > + MACHINE_CFLAGS +=3D -mno-avx512f > + endif > +endif > endif > endif >=20 > --=20 > 2.11.0 >=20 Regards, Keith