From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5DBC428E3F for ; Wed, 27 Dec 2023 10:06:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="jQuiJLhV" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1703671580; 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; bh=Vpvi0QuylzJT57z4Iry1XFcRTO36VgwNkYMSy6kylAQ=; b=jQuiJLhVeDlz2xfDFyT9fIcVGOhJ1/uX0Ejmm76mK/LIyFDiTUqWnVN7OWD570CWhHmaKC 1fBpAY06BMcjOVzdyws5CY2Hy3MWM/6BZ1uIZ1caQvZ+pwfnn0h5MM3Xp0Xd1lTSiPQrZ9 aS4z6yYqtZx/tR3WtDjAc2izAImx2+I= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-634-aZDQSISOPbeqMO1_L2gTJg-1; Wed, 27 Dec 2023 05:06:18 -0500 X-MC-Unique: aZDQSISOPbeqMO1_L2gTJg-1 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-40d5d0de143so5983405e9.1 for ; Wed, 27 Dec 2023 02:06:18 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1703671577; x=1704276377; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=Vpvi0QuylzJT57z4Iry1XFcRTO36VgwNkYMSy6kylAQ=; b=pn5d0DJ5VWrQ18RlJNTLcHfW2hGCG4rGy3YbXFQLjaryUgCdG+EQPuui4pzW2l5zZx bNH8j0rKwFwKxYrzuAhHs8fQSGEd7etMuEhZ3k+D01OxBdgH+H14SwH6L7+dfYcXhcQg auSYMzH4mTGVIijGizX17FxwZWNXIee6OCfNcJqJ9aSoaN7Lo4ozTV6VXK0ZyEzVE17b AG7/nqErcv3jPYcDdF9qeOg/Q+DHZiYzIrE21WLQhaRy/DNKjnDrPTZHrmQRYsH/GUVN bYlCnhX/Ys9OKE54RMRHSm2xC9mobEJ/jiabKW9Q8vzEWXmUy53IplnkvG5E/j040KRh aB3Q== X-Gm-Message-State: AOJu0Yzb62Jl41a6U9eifXrmJhWVzUrWHBcXQ6Wm/5sw+06UENmkbu8z aZuV/QTeQ2d1sNBMKQvuF91ScTxxZbKG45WLQd0yVsYfmMuipduoixbhAdO7yPzaMEf/Z9uEn5w dFcwDTrTYUtM8ZmuePWDfvDv9pFIcSCnohAU= X-Received: by 2002:a05:600c:3f94:b0:40d:5e3e:33af with SMTP id fs20-20020a05600c3f9400b0040d5e3e33afmr217827wmb.51.1703671577590; Wed, 27 Dec 2023 02:06:17 -0800 (PST) X-Google-Smtp-Source: AGHT+IG5FpgrgHxxLBaIeXm7LTM0yLsMuN+g4thXte0aFhycFE23DDxpgalZv2U5QOQ/j0TgZHDoNg== X-Received: by 2002:a05:600c:3f94:b0:40d:5e3e:33af with SMTP id fs20-20020a05600c3f9400b0040d5e3e33afmr217822wmb.51.1703671577203; Wed, 27 Dec 2023 02:06:17 -0800 (PST) Received: from redhat.com ([2.55.177.189]) by smtp.gmail.com with ESMTPSA id r19-20020a05600c459300b0040d128e9c62sm31122809wmo.18.2023.12.27.02.06.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 27 Dec 2023 02:06:16 -0800 (PST) Date: Wed, 27 Dec 2023 05:06:12 -0500 From: "Michael S. Tsirkin" To: Li Feng Cc: Paolo Bonzini , Jens Axboe , Jason Wang , Stefan Hajnoczi , Xuan Zhuo , "open list:BLOCK LAYER" , linux-kernel , "open list:VIRTIO BLOCK AND SCSI DRIVERS" Subject: Re: [PATCH] virtio_blk: set the default scheduler to none Message-ID: <20231227050544-mutt-send-email-mst@kernel.org> References: <20231207043118.118158-1-fengli@smartx.com> <20231225092010-mutt-send-email-mst@kernel.org> <20231226103743-mutt-send-email-mst@kernel.org> <2E148FC5-F9A9-4A86-99F1-8D0B93412181@smartx.com> Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 In-Reply-To: <2E148FC5-F9A9-4A86-99F1-8D0B93412181@smartx.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Wed, Dec 27, 2023 at 03:26:30PM +0800, Li Feng wrote: > > > > On Dec 26, 2023, at 23:38, Michael S. Tsirkin wrote: > > > > On Tue, Dec 26, 2023 at 05:01:40PM +0800, Li Feng wrote: > >> I don't have ideas right now to answer Christoph/Paolo's question. > > > > Paolo did some testing on this thread and posted some concerns. > > Do you disagree with his analysis? > > Paolo gave a very detailed data analysis. Indeed, in some low queue depth > scenarios, the data dropped somewhat. However, I suspect that it may be > caused by other problems (such as test fluctuations) rather than the benefits > brought by deadline. Maybe. I think it would be up to you to prove this then. > BTW, I think 128 queue depth test is a very important and common performance > test item for storage devices. > > Thanks, > Li > > > > > -- > > MST > >