From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <dev-bounces@dpdk.org> Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 51D93A3168 for <public@inbox.dpdk.org>; Wed, 16 Oct 2019 10:09:02 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id DDFAA1E901; Wed, 16 Oct 2019 10:09:00 +0200 (CEST) Received: from us-smtp-1.mimecast.com (us-smtp-delivery-1.mimecast.com [207.211.31.120]) by dpdk.org (Postfix) with ESMTP id 065131E8FF for <dev@dpdk.org>; Wed, 16 Oct 2019 10:08:58 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1571213338; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=8NGQ0tZADhCy2ZDFqQlja3g0keK4WsEfwG/9tLw8pqI=; b=WR4PMGhGfH/E4RXt/SVClvIU+gsG6pKtxMz6SEdbyUSsy6AA0kRlc7Ma6BYiOcqkSMvUEn u84y8nhxnxOf+9eLspydH2lmdLGjlsgAXMjCMcrKsbfgZ5h83GmTxmX0bu42A7SxEE71tV 6i9YZU0jn2ktqBzhTj47CmIt1EIAK9Y= Received: from mail-ua1-f69.google.com (mail-ua1-f69.google.com [209.85.222.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-359-elbnoduTOC-uYfxMwKf-_w-1; Wed, 16 Oct 2019 04:08:57 -0400 Received: by mail-ua1-f69.google.com with SMTP id m45so5117953uae.18 for <dev@dpdk.org>; Wed, 16 Oct 2019 01:08:57 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=WC9GVmbpmb9ZobY9UcZ1L5ppL/eTycF4hsImtE2K05g=; b=gQBGLA++WsA3SeJ1pQvfl8+suBRoFiJ8ejlJWm3q5DyjuhdJ/ZfU+0KxK/abZGNoFY vA8KcRLMouvmRcD8AA3m82w7TlCiH2Ei8lHr2Ay6JVF6S8my2WfMRavpVZXtu94tfGDx Pp9ZPw2u/V1LlOlhgJIYvZATjNGlPKHCQToSOsR97eQmoiLOlwi8VwfKC1zWN9lebhQd TqEBD8gjXJjuHkW0o1wDbHKNqmm1Cntog4y9tSk91F32HB//H2BPsFnUXHi/56zscUBm SQJLgD1ezLPWbioyyaM4uH8uqP/LxdWtqyuSSwrsmvdnTY3CullbDcMI8axxUreaDqu4 +pow== X-Gm-Message-State: APjAAAW7oqwD494xnhLsxPPIzAUBgSUvdS8tczbzBpefuEwK72l8+YQ2 XFbh+DUFMeCa+PwZQA1rIUkTb8I9aiFlyhMque25IJqOgre8YYQd38svO47PJY/s9GfwhiKmaHk PmiZJHyD7tnj8ubAPOtg= X-Received: by 2002:ab0:7107:: with SMTP id x7mr17388057uan.87.1571213336639; Wed, 16 Oct 2019 01:08:56 -0700 (PDT) X-Google-Smtp-Source: APXvYqzmKKsz2ZDEVlDw4IrONWpURvyeSF1w0qtl7bjYSM14BvcEz51z4M5f5a3x6Gnlf5HA/nQXDPrKRDaFPMRhF10= X-Received: by 2002:ab0:7107:: with SMTP id x7mr17388048uan.87.1571213336268; Wed, 16 Oct 2019 01:08:56 -0700 (PDT) MIME-Version: 1.0 References: <1561911676-37718-1-git-send-email-gavin.hu@arm.com> <1566454356-37277-1-git-send-email-gavin.hu@arm.com> In-Reply-To: <1566454356-37277-1-git-send-email-gavin.hu@arm.com> From: David Marchand <david.marchand@redhat.com> Date: Wed, 16 Oct 2019 10:08:44 +0200 Message-ID: <CAJFAV8xV+=+wntcH7AKh3tEa8CvAUYjCun0KbSfBmbZhrHvNSg@mail.gmail.com> To: Bruce Richardson <bruce.richardson@intel.com>, "Ananyev, Konstantin" <konstantin.ananyev@intel.com>, David Christensen <drc@linux.vnet.ibm.com> Cc: dev <dev@dpdk.org>, Gavin Hu <gavin.hu@arm.com>, nd <nd@arm.com>, Thomas Monjalon <thomas@monjalon.net>, Stephen Hemminger <stephen@networkplumber.org>, Jerin Jacob Kollanukkaran <jerinj@marvell.com>, Pavan Nikhilesh <pbhagavatula@marvell.com>, Honnappa Nagarahalli <Honnappa.Nagarahalli@arm.com> X-MC-Unique: elbnoduTOC-uYfxMwKf-_w-1 X-Mimecast-Spam-Score: 0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Subject: Re: [dpdk-dev] [PATCH v4 0/6] use WFE for locks and ring on aarch64 X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions <dev.dpdk.org> List-Unsubscribe: <https://mails.dpdk.org/options/dev>, <mailto:dev-request@dpdk.org?subject=unsubscribe> List-Archive: <http://mails.dpdk.org/archives/dev/> List-Post: <mailto:dev@dpdk.org> List-Help: <mailto:dev-request@dpdk.org?subject=help> List-Subscribe: <https://mails.dpdk.org/listinfo/dev>, <mailto:dev-request@dpdk.org?subject=subscribe> Errors-To: dev-bounces@dpdk.org Sender: "dev" <dev-bounces@dpdk.org> Hello guys, This series got a lot of attention from ARM people and it seems ready for integration. But I did not see comment from other architectures, could you have a look please? Thanks. --=20 David Marchand On Thu, Aug 22, 2019 at 8:13 AM Gavin Hu <gavin.hu@arm.com> wrote: > > DPDK has multiple use cases where the core repeatedly polls a location in > memory. This polling results in many cache and memory transactions. > > Arm architecture provides WFE (Wait For Event) instruction, which allows > the cpu core to enter a low power state until woken up by the update to t= he > memory location being polled. Thus reducing the cache and memory > transactions. > > x86 has the PAUSE hint instruction to reduce such overhead. > > The rte_wait_until_equal_xxx APIs abstract the functionality of 'polling > for a memory location to become equal to a given value'. > > For non-Arm platforms, these APIs are just wrappers around do-while loop > with rte_pause, so there are no performance differences. > > For Arm platforms, use of WFE can be configured using CONFIG_RTE_USE_WFE > option. It is disabled by default. > > Currently, use of WFE is supported only for aarch64 platforms. armv7 > platforms do support the WFE instruction, but they require explicit wake = up > events(sev) and are less performannt. > > Testing shows that, performance varies across different platforms, with > some showing degradation. > > CONFIG_RTE_ARM_USE_WFE should be enabled depending on the performance > benchmarking on the target platforms. Power saving should be an bonus, > but currenly we don't have ways to characterize that. > > V4: > - rename the config as CONFIG_RTE_ARM_USE_WFE to indicate it applys to ar= m only > - introduce a macro for assembly Skelton to reduce the duplication of cod= e > - add one patch for nxp fslmc to address a compiling error > V3: > - Convert RFCs to patches > V2: > - Use inline functions instead of marcos > - Add load and compare in the beginning of the APIs > - Fix some style errors in asm inline > V1: > - Add the new APIs and use it for ring and locks > > Gavin Hu (6): > bus/fslmc: fix the conflicting dmb function > eal: add the APIs to wait until equal > ticketlock: use new API to reduce contention on aarch64 > ring: use wfe to wait for ring tail update on aarch64 > spinlock: use wfe to reduce contention on aarch64 > config: add WFE config entry for aarch64 > > config/arm/meson.build | 1 + > config/common_base | 6 +++++ > drivers/bus/fslmc/mc/fsl_mc_sys.h | 10 +++++--- > drivers/bus/fslmc/mc/mc_sys.c | 3 +-- > .../common/include/arch/arm/rte_pause_64.h | 30 ++++++++++++++++= ++++++ > .../common/include/arch/arm/rte_spinlock.h | 25 ++++++++++++++++= ++ > lib/librte_eal/common/include/generic/rte_pause.h | 26 ++++++++++++++++= ++- > .../common/include/generic/rte_ticketlock.h | 3 +-- > lib/librte_ring/rte_ring_c11_mem.h | 4 +-- > lib/librte_ring/rte_ring_generic.h | 3 +-- > 10 files changed, 99 insertions(+), 12 deletions(-) > > -- > 2.7.4 >