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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DB1E2C4332F for ; Thu, 13 Oct 2022 04:46:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229614AbiJMEqo (ORCPT ); Thu, 13 Oct 2022 00:46:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38730 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229541AbiJMEqm (ORCPT ); Thu, 13 Oct 2022 00:46:42 -0400 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4F98BF1932; Wed, 12 Oct 2022 21:46:41 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 08B27B81C22; Thu, 13 Oct 2022 04:46:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 50757C433D7; Thu, 13 Oct 2022 04:46:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1665636398; bh=pGayVfPonl3TOVCWnaUNxoqRflw7kK3LilXAze3Di2o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=OfWnBTzxrMhAL5pZu1woysiViYJ7xSmiHXD4iRbuQiKNy3CUFbTJZmGyFUHIqG6VT dQVNW63Kb54peCNAvKBJM0WJg9VMPDU0vJBfwHHmrzRBjTyhSII/4PHJ43PWISIY89 vBNSqWYLEc6On1f2uMazCgG/keMiZ/jfC02SEpYk= Date: Thu, 13 Oct 2022 06:47:22 +0200 From: Greg KH To: Saurabh Singh Sengar Cc: ssengar@microsoft.com, kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com, wei.liu@kernel.org, decui@microsoft.com, longli@microsoft.com, linux-hyperv@vger.kernel.org, linux-kernel@vger.kernel.org, mikelley@microsoft.com Subject: Re: [PATCH] uio_hv_generic: Enable support for slower vmbus device channels Message-ID: References: <1665575806-27990-1-git-send-email-ssengar@linux.microsoft.com> <20221013041515.GA12822@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20221013041515.GA12822@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Oct 12, 2022 at 09:15:15PM -0700, Saurabh Singh Sengar wrote: > On Wed, Oct 12, 2022 at 05:54:07PM +0200, Greg KH wrote: > > On Wed, Oct 12, 2022 at 05:52:05PM +0200, Greg KH wrote: > > > On Wed, Oct 12, 2022 at 04:56:46AM -0700, Saurabh Sengar wrote: > > > > This patch enables support for slower vmbus channels, which consist > > > > of following 3 changes : > > > > 1. Support for hypercalls > > > > 2. Module params for recv/send buffer sizes > > > > 3. Module param for custom ring buffer sizes > > > > > > Even if this all was ok, you are doing 3 things all in one change, > > > that's not allowed at all, you all know this. > > > > > > Anyway, no new module parameters, this is not the 1990's, we have much > > > better ways to do this properly (hint, module parameters modify code, > > > you want to modify the options of a specific device.) > > > > Also, you give no good reason for why this is needed at all, nor how > > anyone would use these options and why they would need to. > > > > The kernel should "just work" and not require manual intervention by a > > user. Dynamically fix this based on the device, do NOT force a user to > > have to attempt to "tune" anything, that will never work properly over > > time, AND you are being lazy and forcing each individual user to do the > > work, making more effort needed overall than just doing it properly in > > the kernel. > > Let me find a method if we can avoid using module parameters, this may result > in hardcoding values in the vmbus driver code for various devices, giving less > flexibilty to user. A user should not be using the uio driver for any of that, so I doubt this is a real issue :) thanks, greg k-h