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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 32BD2C10F0B for ; Tue, 2 Apr 2019 17:53:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 14F2A2082C for ; Tue, 2 Apr 2019 17:53:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730805AbfDBRxR (ORCPT ); Tue, 2 Apr 2019 13:53:17 -0400 Received: from mail-qt1-f196.google.com ([209.85.160.196]:34431 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730220AbfDBRxR (ORCPT ); Tue, 2 Apr 2019 13:53:17 -0400 Received: by mail-qt1-f196.google.com with SMTP id k2so16339350qtm.1 for ; Tue, 02 Apr 2019 10:53:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=OLJXHlhYI15g5py0OlU6OBcth4eT+AVlpGiVwqABwyM=; b=DFNmja42yMbdP8JPbeLau7M999bZ5Z5wpgDer33+SghDLfeCOe/xROXijtYLsUoQAf UQn7PH+TVPrYBu0bVEfK5BH2PDbrjjZ+Y5p/MnmvN/z+rs0y7N9/RnZlC5EYttSpXPKe HAjow7qXKoUHBgr+gtDVpO+RACuMlanXGZfmLJ7cc7x6Prh01rRDxQpYfQQceG8LjfO8 aGGtuBHJREsSmmryJ1QytvWcGem2vUbEwIlWY4V2wOQInQ5c10Qg5w+70+XdNA9td0Fg R9BupsZ+enBUJ1OZgvmTQz95nVL2nox85DdjIA7fJZsz6iMKx+8Sq/9AI+62eEsS2XZo FxhQ== X-Gm-Message-State: APjAAAVQDltw1Kj1Hux+XMSMMLe7qHzgA7eBtLTrCGd4SNI5hfYLY7/D NDF7CHUrjwucIA2ZFiEWM9DvVQ== X-Google-Smtp-Source: APXvYqwBiZji2CbrWAPhiXLkuH2SxquqiO4kBtgNqdomsId+YeuaIw+i15Rp6ZVpaVK2OIU9Uu9l2g== X-Received: by 2002:a0c:b2d6:: with SMTP id d22mr58846546qvf.39.1554227596333; Tue, 02 Apr 2019 10:53:16 -0700 (PDT) Received: from redhat.com ([66.187.232.66]) by smtp.gmail.com with ESMTPSA id y197sm7267625qkb.23.2019.04.02.10.53.14 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 02 Apr 2019 10:53:15 -0700 (PDT) Date: Tue, 2 Apr 2019 13:53:12 -0400 From: "Michael S. Tsirkin" To: Alexander Duyck Cc: David Hildenbrand , Nitesh Narayan Lal , kvm list , LKML , linux-mm , Paolo Bonzini , lcapitulino@redhat.com, pagupta@redhat.com, Yang Zhang , Rik van Riel , dodgen@google.com, Konrad Rzeszutek Wilk , dhildenb@redhat.com, Andrea Arcangeli , Dave Hansen Subject: Re: On guest free page hinting and OOM Message-ID: <20190402134722-mutt-send-email-mst@kernel.org> References: <20190401104608-mutt-send-email-mst@kernel.org> <6a612adf-e9c3-6aff-3285-2e2d02c8b80d@redhat.com> <20190402112115-mutt-send-email-mst@kernel.org> <3dd76ce6-c138-b019-3a43-0bb0b793690a@redhat.com> <6b0a3610-0e7b-08dc-8b5f-707062f87bea@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 02, 2019 at 10:45:43AM -0700, Alexander Duyck wrote: > We went through this back in the day with > networking. Adding more buffers is not the solution. The solution is > to have a way to gracefully recover and keep our hinting latency and > buffer bloat to a minimum. That's an interesting approach, I think that things that end up working well are NAPI (asychronous notifications), limited batching, XDP (big aligned buffers) and BQL (accounting). Is that your perspective too? -- MST