From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mails.dpdk.org (mails.dpdk.org [217.70.189.124]) by inbox.dpdk.org (Postfix) with ESMTP id 2138046A19; Thu, 26 Jun 2025 17:22:00 +0200 (CEST) Received: from mails.dpdk.org (localhost [127.0.0.1]) by mails.dpdk.org (Postfix) with ESMTP id 99B074021F; Thu, 26 Jun 2025 17:21:59 +0200 (CEST) Received: from fhigh-a8-smtp.messagingengine.com (fhigh-a8-smtp.messagingengine.com [103.168.172.159]) by mails.dpdk.org (Postfix) with ESMTP id D8A3740156 for ; Thu, 26 Jun 2025 17:21:58 +0200 (CEST) Received: from phl-compute-06.internal (phl-compute-06.phl.internal [10.202.2.46]) by mailfhigh.phl.internal (Postfix) with ESMTP id 50622140003F; Thu, 26 Jun 2025 11:21:58 -0400 (EDT) Received: from phl-mailfrontend-02 ([10.202.2.163]) by phl-compute-06.internal (MEProxy); Thu, 26 Jun 2025 11:21:58 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=monjalon.net; h= cc:cc:content-transfer-encoding:content-type:content-type:date :date:from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to; s=fm2; t=1750951318; x=1751037718; bh=tEW+bSTThh5Y+TfJzcr3W6kLwZojxIOqfDfOMbNAKWI=; b= yleBnn5UdhuIb/nTTxd7gqX6Q3J/YTevJVurgrRT1Be0jtA2FXQ0FrU7kusealwZ 3cEanCnnn7zPIN9VYi7BJbGE+iVLnncqY+RHOXhH0yiLw8oH2DWUMBBOJFHqoVu/ 20R3DT/oVv3b6x+bGlq9CML6zqFtMD4QjTuQ2F57q7BwfGKOWLKBu+4dQ4n8Krr8 fJNP3N4J4lZ2RU+OqvmbdcDLjQ08LGUlEHMFrR0iQDJXWtwLhNBVzqsKkmyDpYhh qEK3BRwjIF+Gw1sGflMb9rdqwmpAxMB4++Ub7r53648c2IoK9gc7Ul3WwY1hzY14 1FNAhMawK+vzWlrvj518oQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:feedback-id:feedback-id :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t=1750951318; x= 1751037718; bh=tEW+bSTThh5Y+TfJzcr3W6kLwZojxIOqfDfOMbNAKWI=; b=H 9UhUigqMf4ChhOxIdGxynfr2rC77ttMS2wRy2KA8ju7ElypA1J3FmuNDnYSjFayu sFr+dB8MRQPwCAeF3rJdhfF9oN/cQp3QKDD/hCghpBc2fMNXTaeXnBxmKi3JPitp rDRw9AVk2TseYuG998WxlETEFj8N03fKo5LGcxmIQX+S+/LUHpt0xd29B1NTOVqX Du3XDzJeTLPsxPCyiCLSKO4ELYcaMt1oKR9qPxh9Qe3xmrd+vVHJSnkCi7JBImhU rcG5psBA/L44lCwnFLm1ZZGJyQRc4MymonWzLt/zRFTlbK46pcokOnoRFrHqhfQD dy5/czL7CDLw1JS8d4XPg== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeeffedrtdefgdehfecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpuffrtefokffrpgfnqfghnecuuegrihhl ohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpe fhvfevufffkfgjfhgggfgtsehtqhertddttdejnecuhfhrohhmpefvhhhomhgrshcuofho nhhjrghlohhnuceothhhohhmrghssehmohhnjhgrlhhonhdrnhgvtheqnecuggftrfgrth htvghrnhepgedttdeljeejgeffkeekkedtjeevtdehvedtkeeivdeuuedvieduvdelveej ueejnecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpehmrghilhhfrhhomhepth hhohhmrghssehmohhnjhgrlhhonhdrnhgvthdpnhgspghrtghpthhtohepkedpmhhouggv pehsmhhtphhouhhtpdhrtghpthhtohepsghinhhgiiesnhhvihguihgrrdgtohhmpdhrtg hpthhtohepshhtvghphhgvnhesnhgvthifohhrkhhplhhumhgsvghrrdhorhhgpdhrtghp thhtohepvhhirggthhgvshhlrghvohesnhhvihguihgrrdgtohhmpdhrtghpthhtohepmh grthgrnhesnhhvihguihgrrdgtohhmpdhrtghpthhtohepuggvvhesughpughkrdhorhhg pdhrtghpthhtohepughsohhsnhhofihskhhisehnvhhiughirgdrtghomhdprhgtphhtth hopehsuhgrnhhmihhnghhmsehnvhhiughirgdrtghomhdprhgtphhtthhopehrrghslhgr nhgusehnvhhiughirgdrtghomh X-ME-Proxy: Feedback-ID: i47234305:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 26 Jun 2025 11:21:56 -0400 (EDT) From: Thomas Monjalon To: Bing Zhao , Stephen Hemminger Cc: Slava Ovsiienko , Matan Azrad , dev , Dariusz Sosnowski , Suanming Mou , Raslan Darawsheh Subject: Re: [PATCH v2 2/3] net/mlx5: add new devarg for Tx queue consecutive memory Date: Thu, 26 Jun 2025 17:21:55 +0200 Message-ID: <5112176.f0I1acK8xe@thomas> In-Reply-To: <20250626072954.6ca04456@hermes.local> References: <20250623183456.130666-1-bingz@nvidia.com> <20250626072954.6ca04456@hermes.local> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org 26/06/2025 16:29, Stephen Hemminger: > On Thu, 26 Jun 2025 13:18:18 +0000 > Bing Zhao wrote: >=20 > > Hi Stephen, > >=20 > > Thanks for your review and comments. I will add the description about t= he new devarg in our mlx5.rst file to have a detailed description. > > Indeed, after some review and internal call discussion with our datapat= h experts. We would like to change the devarg a little bit but not only 0 /= 1 as a chicken bit. > >=20 > > Since the memory accessing footprints and orders may impact the perform= ance. In the perf test, we found that the alignment of the queue address ma= y impact it. The basic starting address alignment is system page size, but = it can be bigger. > > So the new devarg use will be the log value of the alignment for all qu= eues=E2=80=99 starting addresses. And on different CPU architectures / gene= rations that have different LLC systems can try to use different alignment = to get the best performance without rebuilding the binary application from = the source code and it is configurable. WDYT? >=20 > Please make it automatic, the driver already has too many config bits. > The users should just get good performance with the default. > If driver needs to it should look at any/all system info to determine wha= t the best setting is. The default would be good enough, but it looks very difficult to know the b= est value. That's why the idea is to allow some tuning here. I agree there are too many devargs for most users, but at the same time DPDK is a project to get the best performance, that's why there are so many tuning possible. I think we can meet both goals by making clear which options are for advanc= ed tuning, so a basic user will not mess with with such options which have a good defa= ult by the way.