From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-11.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A064EC2D0E3 for ; Thu, 17 Sep 2020 18:34:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 47166221F1 for ; Thu, 17 Sep 2020 18:34:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Xord+k8E" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726472AbgIQSeu (ORCPT ); Thu, 17 Sep 2020 14:34:50 -0400 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:50346 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726503AbgIQSdD (ORCPT ); Thu, 17 Sep 2020 14:33:03 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1600367582; 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:autocrypt:autocrypt; bh=zxw5d90miAtxM8P5wNzW5NeHRvhoE+uodlDdPhwXToA=; b=Xord+k8EkUeS5/vEi2JRFz54DPxtjNFcQGy5MoR+a0uRJwJpwSqz50o/L0TnRNXlggMdK9 KrgAOVZCBRqcRBY2kQ3kQAq8KvR7PXhy6p0CF8s1qtZX7msl2q+Xd7RAnfJypxYYc23jeb Gt1QRRvKkxMEQuVJODSO0eC5ZYw8mkw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-284-xzXlq8dcMj2zp5Fb-3iqug-1; Thu, 17 Sep 2020 14:31:12 -0400 X-MC-Unique: xzXlq8dcMj2zp5Fb-3iqug-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id A108B1017DD1; Thu, 17 Sep 2020 18:31:10 +0000 (UTC) Received: from [10.10.112.95] (ovpn-112-95.rdu2.redhat.com [10.10.112.95]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 989EF73665; Thu, 17 Sep 2020 18:31:08 +0000 (UTC) Subject: Re: [RFC][Patch v1 2/3] i40e: limit msix vectors based on housekeeping CPUs To: Jesse Brandeburg Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-pci@vger.kernel.org, frederic@kernel.org, mtosatti@redhat.com, sassmann@redhat.com, jeffrey.t.kirsher@intel.com, jacob.e.keller@intel.com, jlelli@redhat.com, hch@infradead.org, bhelgaas@google.com, mike.marciniszyn@intel.com, dennis.dalessandro@intel.com, thomas.lendacky@amd.com, jerinj@marvell.com, mathias.nyman@intel.com, jiri@nvidia.com, "Luis Claudio R. Goncalves" References: <20200909150818.313699-1-nitesh@redhat.com> <20200909150818.313699-3-nitesh@redhat.com> <20200917112359.00006e10@intel.com> From: Nitesh Narayan Lal Autocrypt: addr=nitesh@redhat.com; prefer-encrypt=mutual; keydata= mQINBFl4pQoBEADT/nXR2JOfsCjDgYmE2qonSGjkM1g8S6p9UWD+bf7YEAYYYzZsLtbilFTe z4nL4AV6VJmC7dBIlTi3Mj2eymD/2dkKP6UXlliWkq67feVg1KG+4UIp89lFW7v5Y8Muw3Fm uQbFvxyhN8n3tmhRe+ScWsndSBDxYOZgkbCSIfNPdZrHcnOLfA7xMJZeRCjqUpwhIjxQdFA7 n0s0KZ2cHIsemtBM8b2WXSQG9CjqAJHVkDhrBWKThDRF7k80oiJdEQlTEiVhaEDURXq+2XmG jpCnvRQDb28EJSsQlNEAzwzHMeplddfB0vCg9fRk/kOBMDBtGsTvNT9OYUZD+7jaf0gvBvBB lbKmmMMX7uJB+ejY7bnw6ePNrVPErWyfHzR5WYrIFUtgoR3LigKnw5apzc7UIV9G8uiIcZEn C+QJCK43jgnkPcSmwVPztcrkbC84g1K5v2Dxh9amXKLBA1/i+CAY8JWMTepsFohIFMXNLj+B RJoOcR4HGYXZ6CAJa3Glu3mCmYqHTOKwezJTAvmsCLd3W7WxOGF8BbBjVaPjcZfavOvkin0u DaFvhAmrzN6lL0msY17JCZo046z8oAqkyvEflFbC0S1R/POzehKrzQ1RFRD3/YzzlhmIowkM BpTqNBeHEzQAlIhQuyu1ugmQtfsYYq6FPmWMRfFPes/4JUU/PQARAQABtCVOaXRlc2ggTmFy YXlhbiBMYWwgPG5pbGFsQHJlZGhhdC5jb20+iQI9BBMBCAAnBQJZeKUKAhsjBQkJZgGABQsJ CAcCBhUICQoLAgQWAgMBAh4BAheAAAoJEKOGQNwGMqM56lEP/A2KMs/pu0URcVk/kqVwcBhU SnvB8DP3lDWDnmVrAkFEOnPX7GTbactQ41wF/xwjwmEmTzLrMRZpkqz2y9mV0hWHjqoXbOCS 6RwK3ri5e2ThIPoGxFLt6TrMHgCRwm8YuOSJ97o+uohCTN8pmQ86KMUrDNwMqRkeTRW9wWIQ EdDqW44VwelnyPwcmWHBNNb1Kd8j3xKlHtnS45vc6WuoKxYRBTQOwI/5uFpDZtZ1a5kq9Ak/ MOPDDZpd84rqd+IvgMw5z4a5QlkvOTpScD21G3gjmtTEtyfahltyDK/5i8IaQC3YiXJCrqxE r7/4JMZeOYiKpE9iZMtS90t4wBgbVTqAGH1nE/ifZVAUcCtycD0f3egX9CHe45Ad4fsF3edQ ESa5tZAogiA4Hc/yQpnnf43a3aQ67XPOJXxS0Qptzu4vfF9h7kTKYWSrVesOU3QKYbjEAf95 NewF9FhAlYqYrwIwnuAZ8TdXVDYt7Z3z506//sf6zoRwYIDA8RDqFGRuPMXUsoUnf/KKPrtR ceLcSUP/JCNiYbf1/QtW8S6Ca/4qJFXQHp0knqJPGmwuFHsarSdpvZQ9qpxD3FnuPyo64S2N Dfq8TAeifNp2pAmPY2PAHQ3nOmKgMG8Gn5QiORvMUGzSz8Lo31LW58NdBKbh6bci5+t/HE0H pnyVf5xhNC/FuQINBFl4pQoBEACr+MgxWHUP76oNNYjRiNDhaIVtnPRqxiZ9v4H5FPxJy9UD Bqr54rifr1E+K+yYNPt/Po43vVL2cAyfyI/LVLlhiY4yH6T1n+Di/hSkkviCaf13gczuvgz4 KVYLwojU8+naJUsiCJw01MjO3pg9GQ+47HgsnRjCdNmmHiUQqksMIfd8k3reO9SUNlEmDDNB XuSzkHjE5y/R/6p8uXaVpiKPfHoULjNRWaFc3d2JGmxJpBdpYnajoz61m7XJlgwl/B5Ql/6B dHGaX3VHxOZsfRfugwYF9CkrPbyO5PK7yJ5vaiWre7aQ9bmCtXAomvF1q3/qRwZp77k6i9R3 tWfXjZDOQokw0u6d6DYJ0Vkfcwheg2i/Mf/epQl7Pf846G3PgSnyVK6cRwerBl5a68w7xqVU 4KgAh0DePjtDcbcXsKRT9D63cfyfrNE+ea4i0SVik6+N4nAj1HbzWHTk2KIxTsJXypibOKFX 2VykltxutR1sUfZBYMkfU4PogE7NjVEU7KtuCOSAkYzIWrZNEQrxYkxHLJsWruhSYNRsqVBy KvY6JAsq/i5yhVd5JKKU8wIOgSwC9P6mXYRgwPyfg15GZpnw+Fpey4bCDkT5fMOaCcS+vSU1 UaFmC4Ogzpe2BW2DOaPU5Ik99zUFNn6cRmOOXArrryjFlLT5oSOe4IposgWzdwARAQABiQIl BBgBCAAPBQJZeKUKAhsMBQkJZgGAAAoJEKOGQNwGMqM5ELoP/jj9d9gF1Al4+9bngUlYohYu 0sxyZo9IZ7Yb7cHuJzOMqfgoP4tydP4QCuyd9Q2OHHL5AL4VFNb8SvqAxxYSPuDJTI3JZwI7 d8JTPKwpulMSUaJE8ZH9n8A/+sdC3CAD4QafVBcCcbFe1jifHmQRdDrvHV9Es14QVAOTZhnJ vweENyHEIxkpLsyUUDuVypIo6y/Cws+EBCWt27BJi9GH/EOTB0wb+2ghCs/i3h8a+bi+bS7L FCCm/AxIqxRurh2UySn0P/2+2eZvneJ1/uTgfxnjeSlwQJ1BWzMAdAHQO1/lnbyZgEZEtUZJ x9d9ASekTtJjBMKJXAw7GbB2dAA/QmbA+Q+Xuamzm/1imigz6L6sOt2n/X/SSc33w8RJUyor SvAIoG/zU2Y76pKTgbpQqMDmkmNYFMLcAukpvC4ki3Sf086TdMgkjqtnpTkEElMSFJC8npXv 3QnGGOIfFug/qs8z03DLPBz9VYS26jiiN7QIJVpeeEdN/LKnaz5LO+h5kNAyj44qdF2T2AiF HxnZnxO5JNP5uISQH3FjxxGxJkdJ8jKzZV7aT37sC+Rp0o3KNc+GXTR+GSVq87Xfuhx0LRST NK9ZhT0+qkiN7npFLtNtbzwqaqceq3XhafmCiw8xrtzCnlB/C4SiBr/93Ip4kihXJ0EuHSLn VujM7c/b4pps Organization: Red Hat Inc, Message-ID: <9a73ab21-1ad6-9a08-b7e7-53ef85649563@redhat.com> Date: Thu, 17 Sep 2020 14:31:07 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <20200917112359.00006e10@intel.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=nitesh@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="KuyjQ2f6cyatlvQOCElcrdtVdI72uU5jx" Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --KuyjQ2f6cyatlvQOCElcrdtVdI72uU5jx Content-Type: multipart/mixed; boundary="CgNCe2qqWcbuAbVd5xdXNH1TGSYkm4r5h" --CgNCe2qqWcbuAbVd5xdXNH1TGSYkm4r5h Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Content-Language: en-US On 9/17/20 2:23 PM, Jesse Brandeburg wrote: > Nitesh Narayan Lal wrote: > >> In a realtime environment, it is essential to isolate unwanted IRQs from >> isolated CPUs to prevent latency overheads. Creating MSIX vectors only >> based on the online CPUs could lead to a potential issue on an RT setup >> that has several isolated CPUs but a very few housekeeping CPUs. This is >> because in these kinds of setups an attempt to move the IRQs to the >> limited housekeeping CPUs from isolated CPUs might fail due to the per >> CPU vector limit. This could eventually result in latency spikes because >> of the IRQ threads that we fail to move from isolated CPUs. >> >> This patch prevents i40e to add vectors only based on available >> housekeeping CPUs by using num_housekeeping_cpus(). >> >> Signed-off-by: Nitesh Narayan Lal > The driver changes are straightforward, but this isn't the only driver > with this issue, right? Indeed, I was hoping to modify them over the time with some testing. > I'm sure ixgbe and ice both have this problem > too, you should fix them as well, at a minimum, and probably other > vendors drivers: Sure, I can atleast include ixgbe and ice in the next posting if that makes sense. The reason I skipped them is that I was not very sure about the right way t= o test these changes. > > $ rg -c --stats num_online_cpus drivers/net/ethernet > ... > 50 files contained matches > > for this patch i40e > Acked-by: Jesse Brandeburg > --=20 Thanks Nitesh --CgNCe2qqWcbuAbVd5xdXNH1TGSYkm4r5h-- --KuyjQ2f6cyatlvQOCElcrdtVdI72uU5jx Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEkXcoRVGaqvbHPuAGo4ZA3AYyozkFAl9jq2sACgkQo4ZA3AYy ozl9Gg/9GwNwBWC1b1qa6LfgFjF0OJqwQ5Or3MrysX70TLodlEvzhtpV2SbTn2md b0pkwoeSZLcYmdDwtxB63o2MPrTWtE6ccNkQTyF1/TZGzxMTHboaDKDXl0IiX7AP 5Xp1rmpufTxdDQYt1pnfWQc+Ao4iIcP2k1liXPsy4Zz08+ljnO3YcUmdd+8ccTWT XWGXZCyHAY3HoRYAsEI9mmULph65fp23k6LKgetozWRe0PHSdt21GRgO54sywtvn JqC5OZTuAWNzzXU1lU6uCp1QXOayn9ZhBr/1+YFI72GcO0fonucZBN0HczbJXiq3 Ej8mdoT6yY0syKvnYAllBAf802qbxSE1Rp6iYlDovym1z7hfo9PlLgjDThZSXyGJ 0BTQqW5CIrznLozhkn2i5kTbEJsUmiyV255jyX6Z7c3WzJUbJTLgcX4IxYuNrzgz 5glxdoitBkDrUrJj106ZtekPMSyyDWuPwB65nZT+k48HB5p9Os1GKF4rn/uCEj2E r3MgBYvg/E6l8IJHBXxN4h/IR70N+xq3CkShWs5FjslpiLdRjT1VpeyCdRb5yRwQ sjOkv9JQhO+JTrsf4/mXBvwI0tbqaQK9r3xDNJhSfkg9VHplHnyiWm2aKxZxh3an 0VbnhaDk9CJ0I8/01lJ/JJGHVgfPofTZLLFxb8l2WlLJLHkDqQk= =klHd -----END PGP SIGNATURE----- --KuyjQ2f6cyatlvQOCElcrdtVdI72uU5jx--