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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT 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 84E5AC282D0 for ; Tue, 29 Jan 2019 06:29:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5700620989 for ; Tue, 29 Jan 2019 06:29:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727195AbfA2G3m (ORCPT ); Tue, 29 Jan 2019 01:29:42 -0500 Received: from verein.lst.de ([213.95.11.211]:44285 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725795AbfA2G3m (ORCPT ); Tue, 29 Jan 2019 01:29:42 -0500 Received: by newverein.lst.de (Postfix, from userid 2407) id 507FF68CEB; Tue, 29 Jan 2019 07:29:40 +0100 (CET) Date: Tue, 29 Jan 2019 07:29:40 +0100 From: Christoph Hellwig To: Jens Axboe Cc: Christoph Hellwig , linux-fsdevel@vger.kernel.org, linux-aio@kvack.org, linux-block@vger.kernel.org, jmoyer@redhat.com, avi@scylladb.com Subject: Re: [PATCH 09/13] io_uring: add submission polling Message-ID: <20190129062940.GB2996@lst.de> References: <20190123153536.7081-1-axboe@kernel.dk> <20190123153536.7081-12-axboe@kernel.dk> <20190128150926.GB10110@lst.de> <9cf014d9-cf16-fa49-83f0-0e9ddb57cc81@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <9cf014d9-cf16-fa49-83f0-0e9ddb57cc81@kernel.dk> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Jan 28, 2019 at 10:05:37AM -0700, Jens Axboe wrote: > >> 2) Probably want the application to pass in the appropriate grace > >> period, not hard code it at 1 second. > > > > 2) actually sounds really useful. Should we look into it ASAP? > > I think so. Question is what kind of granularity we need for this. I > think we can go pretty coarse and keep it in msec, using a short to > pass this in like we do for the thread CPU. That gives us 0..65535 msec, > which should be plenty of range. msec granualarity sounds fine. But is it really worth using a short instead of a 32-bit value these days? Also 16385 seems very limiting for a cpu value, especially as our normal cpu ids are ints.