From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 433C7A04B6; Mon, 12 Oct 2020 11:41:39 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 2306B1D635; Mon, 12 Oct 2020 11:41:38 +0200 (CEST) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [216.205.24.124]) by dpdk.org (Postfix) with ESMTP id A38951D62C for ; Mon, 12 Oct 2020 11:41:36 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1602495695; 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: in-reply-to:in-reply-to:references:references; bh=KzTvR+6zXGpChIz3rWkOLsskGjARP0h83mQkhv9yaN4=; b=LVBBXufiJmie9t0/9gEBRz9utpqel6+9A0We6yYXje2KIfbRJ7ywjeqxDQPEBhsJnOzQXc U/uscXRxeC8Jguuz1KSW++E6A8BcuAHmU8TQNytpafE1CvvrTDs1iYP6tcjI7wu2LAQATk 0rBuc6xLPxpECt1sO/sZrhts4cuTh/E= Received: from mail-vs1-f69.google.com (mail-vs1-f69.google.com [209.85.217.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-29-dtrZ1TviPnm0apm0tkKelw-1; Mon, 12 Oct 2020 05:41:31 -0400 X-MC-Unique: dtrZ1TviPnm0apm0tkKelw-1 Received: by mail-vs1-f69.google.com with SMTP id u12so3892753vsh.18 for ; Mon, 12 Oct 2020 02:41:31 -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=KzTvR+6zXGpChIz3rWkOLsskGjARP0h83mQkhv9yaN4=; b=S+tFElC9DS++gVFsexWWX1cSwdndY5gf+pbFi6Lr8+qiKgm/m+yxDBoXvjU9J+G9Gk 80Omjc03ofAVco9ciifhOy+ef4ro4q6MsSSg7FtXEc7ADXffig6c5MBOpiMJf2pTvv6P Xqd3osM6/05lu0fG+ISkZkezDIql+z46WM4Bp0nFCBBFyLhMWWQTkfWOcp+8pOvyXn06 wTewQXj/td+UbxzIOfeuyYNNTGtqbBbpUSnxa9BP+yscLWdyeHwYpQwXFryI7cZMeJn3 e0Y8O340eDM9a2rNEZYv/ZVLzP9n8qzkcYS/YivDBpacUFdqqjLfh/0gb1YX+7HVshGk 2wOQ== X-Gm-Message-State: AOAM533C7Ct+YiAtO/B4Yju2oDGsqutqK3WAwqDXk+4NgHV4W0dlYtqK +oUab+5GqvubNeMtSp83hGBn+BfQo5B5jmkOUuBUMLBnRJQ6pICouznVL+orrd0iyW/aPtZ7TgV qBtbEJ/ZTSkiGoZDKFiU= X-Received: by 2002:ab0:7313:: with SMTP id v19mr12089975uao.87.1602495690691; Mon, 12 Oct 2020 02:41:30 -0700 (PDT) X-Google-Smtp-Source: ABdhPJx5a7pobH1/G5eIhBgKl1u8laNvqVykcZRqVAiM/M1tA85r+Hi5xtMzTiepsp2LFfTNToxDvsMtYjT/K5/7+2o= X-Received: by 2002:ab0:7313:: with SMTP id v19mr12089961uao.87.1602495690303; Mon, 12 Oct 2020 02:41:30 -0700 (PDT) MIME-Version: 1.0 References: <1599700614-22809-1-git-send-email-omkar.maslekar@intel.com> <1601512112-12577-1-git-send-email-omkar.maslekar@intel.com> <1601512112-12577-2-git-send-email-omkar.maslekar@intel.com> <20201008090243.GA1106@bricha3-MOBL.ger.corp.intel.com> In-Reply-To: <20201008090243.GA1106@bricha3-MOBL.ger.corp.intel.com> From: David Marchand Date: Mon, 12 Oct 2020 11:41:19 +0200 Message-ID: To: Bruce Richardson Cc: Omkar Maslekar , dev , "Ananyev, Konstantin" , Ciara Loftus , David Christensen , Jerin Jacob Kollanukkaran , Honnappa Nagarahalli , "Ruifeng Wang (Arm Technology China)" , Jan Viktorin , Thomas Monjalon Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dmarchan@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="UTF-8" Subject: Re: [dpdk-dev] [PATCH v5] eal: add cache-line demote support X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Thu, Oct 8, 2020 at 11:02 AM Bruce Richardson wrote: > > On Thu, Oct 08, 2020 at 09:09:52AM +0200, David Marchand wrote: > > On Thu, Oct 1, 2020 at 2:30 AM Omkar Maslekar wrote: > > > > > > rte_cldemote is similar to a prefetch hint - in reverse. cldemote(addr) > > > enables software to hint to hardware that line is likely to be shared. > > > Useful in core-to-core communications where cache-line is likely to be > > > shared. ARM and PPC implementation is provided with NOP and can be added > > > if any equivalent instructions could be used for implementation on those > > > architectures. > > > > > > Signed-off-by: Omkar Maslekar > > > Acked-by: Bruce Richardson > > > > I find this "rte_cldemote" name too close to the Intel instruction, > > but I can see no complaint from other arch maintainers, so I guess > > everyone is happy with it. > > It is very close, alright - though the name too does fairly well convey the > likely actual done by the instruction.. Is there a suggestion for a better, > more generic name. I don't have a better suggestion. The prefetch API has some hints on the level of cache to put data in. For this new API, we have no indication, would it make sense? Is this available on all Intel CPUs supported with DPDK? No cpuflag check needed? > > > In any case, this is a new API, so it should be marked experimental. > > > Agreed. > > > As for unit tests, not sure there is much to do, maybe rename > > test_prefetch.c and call this new API too, wdyt? > > > I'm not sure how much value this would provide, but it can be done. As much as the existing test, checking we can call this API. If you think it is not worth it, we can drop the prefetch ut code. -- David Marchand