Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936897AbdLRRAU convert rfc822-to-8bit (ORCPT ); Mon, 18 Dec 2017 12:00:20 -0500 Received: from mout.gmx.net ([212.227.17.22]:55342 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S935504AbdLRRAO (ORCPT ); Mon, 18 Dec 2017 12:00:14 -0500 Message-ID: <1513616405.7113.18.camel@gmx.de> Subject: Re: NFS: 82ms wakeup latency 4.14-rc4 From: Mike Galbraith To: "J. Bruce Fields" Cc: lkml , Jeff Layton , linux-nfs@vger.kernel.org Date: Mon, 18 Dec 2017 18:00:05 +0100 In-Reply-To: <20171218163559.GA11829@fieldses.org> References: <1513610231.7998.13.camel@gmx.de> <1513611112.7113.1.camel@gmx.de> <20171218163559.GA11829@fieldses.org> Content-Type: text/plain; charset="ISO-8859-15" X-Mailer: Evolution 3.20.5 Mime-Version: 1.0 Content-Transfer-Encoding: 8BIT X-Provags-ID: V03:K0:8pR91IGUnn/DnoWcxLLIGobic4AnhbniOc05QBdaRJfi/6invHz YSxMiUYyOIBGsGUH5ABYzw9CBznq50HM0z/BHBvVbSkbcmsJbWaRYn8doT7XCRzBT+K072n ojPHy722ET9vHgC0To7y9HV8TD954ZbMCq9NlOrHkmMSQzPlMagpALaOXMUOhSmJ6VwUz2p W7KyDyAlQl3L4wByF1x+w== X-UI-Out-Filterresults: notjunk:1;V01:K0:zaQEJJZIWAg=:RK2KOk8YDOIsYRDt9eBfVe 2bJ2wSLuyJ/TuLiOZ3t9ZNuq8sTIYcZaPa+5A/T7pQBb9PHKzthOkL1I8bQkyG6yXGh2VN85n nC6LL+7A5oshYLj6d6O5UUy07OqImmUEbaBlo6fJJ0xBWgV3gfEbvN9r43sek7VnwhJD7wR4x +v4wf+vRWYNHcJG4mIalwTnmmNVrI27w7JSlwEFbW/Xq3FT6k4eKXOjQ0J2ehy//8X/Aqu47Y JWzkElIIAkiVtqSfP5RxTh0d6TAARpRqzulWlS5JmWZMj6UnvJJUpXLURhdynKvNg2hAvfKcG nLef0TEzIv53BH7K+ansHv+dRxbB6mX4Ck4uOp3+BgwamcvoK43xYgjB9CPrqDH4iB1yXu21K 8sWqaWuOXPKWAM0NA2FF1F5EKHMzczgFIpSCoQfiVwYYbHxduQzMm9oGbYfZ1QpA3OIaRhCBZ meM1GMWM9FwwgvCNsoE55uNXTv008wKtMrTdaJnJ3j2BGCmo4JKn42yih6t8dmWfb0J3b+F6w vI2lBfV7Z35bwWQRNJBTDR5ROHspL2DkNlLxqFdLI8gpSC8yhOLIEiKPeu8YNQadRpILV4LbO 8ur2WasDemJV2oXWDY4a4wuC3OwEMZi+hjc8udr1UeFq+3P0UiYXkyMdsBgyZzacR0mMcUX+X AA78yo9k0mG5fm6uhyj8+JSvQG1ikNf3hDomGbFzlYPJDUd2447jz4pa2Qoi+UvxtrZREZKEm 0pRjqpnVbLdS1hDvWMv/Tz03DgJmTZpv2s7G7gD1iy8jPp1//FDvYKwl8UTQ5dmwNdXZKdMg3 qdiuBix4lowLI3M5Yg/asEHhxQ+5LfUEASzYygIvSc1OdGNRUo= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 393 Lines: 11 On Mon, 2017-12-18 at 11:35 -0500, J. Bruce Fields wrote: > > Like I say, I don't really understand the issues here, so it's more a > question than an objection.... (I don't know any reason a > cond_resched() would be bad there.) Think of it this way: what all can be queued up behind that kworker that is hogging CPU for huge swaths of time? ?It's not only userspace that suffers. -Mike