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=-5.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 94AB0C433DF for ; Mon, 15 Jun 2020 20:55:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 626F62071A for ; Mon, 15 Jun 2020 20:55:37 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="V+tq2D9Q" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731541AbgFOUzg (ORCPT ); Mon, 15 Jun 2020 16:55:36 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:21540 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726207AbgFOUze (ORCPT ); Mon, 15 Jun 2020 16:55:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592254532; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=OYiL5f6t2DoVF2iRwtKmMIV+W5WN0++ZzqGnAHQLfG0=; b=V+tq2D9QlYE9YmQHT9xKEvgbhuOhA2ND6H1AN8qFTvkBGtrS86ofB37PkoRzFvxpu0qVbm L4TH7aLkDtpJgUTkQFoQ+XNsyzmIKWi6IBlo5pTYCHU+TBPwlHywpIpJty9ghYkdbl/hQW OCo+vdFC7fzu1WMG+hpEvEChN6fQGTk= 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-474-3kelbY72OWKiQosmcPH3tQ-1; Mon, 15 Jun 2020 16:55:28 -0400 X-MC-Unique: 3kelbY72OWKiQosmcPH3tQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8C69A873405; Mon, 15 Jun 2020 20:55:27 +0000 (UTC) Received: from [10.10.114.150] (ovpn-114-150.rdu2.redhat.com [10.10.114.150]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 75BC3768AA; Mon, 15 Jun 2020 20:55:26 +0000 (UTC) Subject: Re: [Patch v1] i40e: limit the msix vectors based on housekeeping CPUs To: "Keller, Jacob E" , "linux-kernel@vger.kernel.org" , "frederic@kernel.org" , "mtosatti@redhat.com" , "sassmann@redhat.com" , "Kirsher, Jeffrey T" , "jlelli@redhat.com" References: <20200615202125.27831-1-nitesh@redhat.com> <20200615202125.27831-2-nitesh@redhat.com> <02874ECE860811409154E81DA85FBB58C25F8001@FMSMSX102.amr.corp.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: Date: Mon, 15 Jun 2020 16:55:25 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.5.0 MIME-Version: 1.0 In-Reply-To: <02874ECE860811409154E81DA85FBB58C25F8001@FMSMSX102.amr.corp.intel.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="oXmH9LDtUOaZu5Owd4qYz5KQq9SeJwmpJ" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --oXmH9LDtUOaZu5Owd4qYz5KQq9SeJwmpJ Content-Type: multipart/mixed; boundary="t5ZUkl7FZIqTqMYEkUlLodjXA4RR8Cjan" --t5ZUkl7FZIqTqMYEkUlLodjXA4RR8Cjan Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Content-Language: en-US On 6/15/20 4:48 PM, Keller, Jacob E wrote: > >> -----Original Message----- >> From: Nitesh Narayan Lal >> Sent: Monday, June 15, 2020 1:21 PM >> To: linux-kernel@vger.kernel.org; frederic@kernel.org; mtosatti@redhat.c= om; >> sassmann@redhat.com; Kirsher, Jeffrey T ; K= eller, >> Jacob E ; jlelli@redhat.com >> Subject: [Patch v1] i40e: limit the msix vectors based on housekeeping C= PUs >> >> 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 online CPUs by using housekeeping_cpumask() to derive >> the number of available housekeeping CPUs. >> >> Signed-off-by: Nitesh Narayan Lal >> --- > Ok, so the idea is that "housekeeping" CPUs are to be used for general pu= rpose configuration, and thus is a subset of online CPUs. By reducing the l= imit to just housekeeping CPUs, we ensure that we do not overload the syste= m with more queues than can be handled by the general purpose CPUs? Yes. General purpose or the housekeeping CPUs or the non-isolated CPUs. > > Thanks, > Jake > --=20 Nitesh --t5ZUkl7FZIqTqMYEkUlLodjXA4RR8Cjan-- --oXmH9LDtUOaZu5Owd4qYz5KQq9SeJwmpJ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEkXcoRVGaqvbHPuAGo4ZA3AYyozkFAl7n4D0ACgkQo4ZA3AYy ozniNg//VHimUukZC0EdnF8hxx1yZ96/bDkBJ0Ys1U6ZEfKK4mXIu7PEh5jMJ83F 4KPp/LK8gIB/0K1MWiVlATv4s90NqECUsbAvgh7IHGb/8X61FL/STlbXRH5TJG+W pN5JFy9YrLgArI0ziY6LR3BrDfY/tGl3u0aDeG10bAHVWqECo8U0bxZsW9q97LFO QME7AsxQKnKpjBaAbFcX5j/GJo4fg/xqyPa8Y/k/E03qAl4SNz+/NxACRis0hCNV dUzNmS/kzY3VkmG7zTKUMbKrWPT6VGnRdmPYW7NtPWTUcYEEH7PoZoBAM9UdChI5 5x7PR69SmJZ4+4lHZFAQ/vlNo/z04LuRM9jwSrAF59j2uj+5jDGPAM4v122503G+ JWfjRvzy2dUdhyVXkyPwlzm7AJ/mVEAPuvqvVyqDE9DhAIc6lTIyPrWK+H27dRje lQlBynfj0o4LT9virt00pgky9awYzyfo/V0bvjKqkQQe4Fb+gNN2vouR/bN6hdM8 2kSO6PKBpFsXpx1NrLA6HgQsKLwo85b/AbOUzSl97uHatHIWmIgA3VjbBt7xUOxq C3iE17Vm/fPXXTwWnCjgxRP73AqInb7rUkKHZIv8+DiBcvfWj2gfy58OdVe+89cZ 06fn/7QudeqS60adomZfjQvzze54mi9WsQMTdWdxnYeF+nBP9ag= =Zz2B -----END PGP SIGNATURE----- --oXmH9LDtUOaZu5Owd4qYz5KQq9SeJwmpJ--