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=ham 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 A2C22C10F0B for ; Tue, 2 Apr 2019 19:49:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 780352075E for ; Tue, 2 Apr 2019 19:49:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730264AbfDBTtG (ORCPT ); Tue, 2 Apr 2019 15:49:06 -0400 Received: from mail-qt1-f196.google.com ([209.85.160.196]:38343 "EHLO mail-qt1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729140AbfDBTtF (ORCPT ); Tue, 2 Apr 2019 15:49:05 -0400 Received: by mail-qt1-f196.google.com with SMTP id d13so16762766qth.5 for ; Tue, 02 Apr 2019 12:49:05 -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=Hj5v9f5m4XcpUD3AHCmGwsgzwcyKpLxNeHtv55UKsvQ=; b=OPdkhTj36sxaN/lwev1Ghu3fLH156ZOkxxgcMiL8Q2THeiS4v5m/skvqAA/vVQxeU/ LBbOMTvH1r8jBV37JW4mMfghGH6YR3uuaIDmFKlnlOQh+oHu047CZB9y5lOqYbmMbVyf GX78LDf4qmUFhVD+lFYgRO3CuqShb9EdUt5UZ2qsZXRfizqVcvU9b46YpZgOUXe7L4Rh +pfX6dLMQwfwiWsCMUOqnIteF/MWX9nHl55PTiU0kdRWJnUDDYZr0DoFgQ5NXLUW1Z8a fjrBNb79JutZfNQfVIu4OUkE29lr4pHEskb/NfjOydjDApFPNHCXfmB2duuMbDN5XLRs 7f7Q== X-Gm-Message-State: APjAAAUH1PmJ98UEw14grOJxTOtuNMmaQXAfr7v/uh0qqGGv5K/alarc D3kMtwPFR+n9gZL3tf9HBkLWng== X-Google-Smtp-Source: APXvYqyssdHTS/DKlsZsXRC9d0R0s3gdduOA5QVLCvuRf6QzAqxPUhlhL0TEas0IduN6EdWwMJPg8g== X-Received: by 2002:ac8:21c7:: with SMTP id 7mr58333120qtz.66.1554234544899; Tue, 02 Apr 2019 12:49:04 -0700 (PDT) Received: from redhat.com ([66.187.232.66]) by smtp.gmail.com with ESMTPSA id a75sm6940361qkg.84.2019.04.02.12.49.02 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 02 Apr 2019 12:49:03 -0700 (PDT) Date: Tue, 2 Apr 2019 15:49:00 -0400 From: "Michael S. Tsirkin" To: David Hildenbrand Cc: Alexander Duyck , 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: <20190402154732-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 08:21:30PM +0200, David Hildenbrand wrote: > The other extreme is a system that barely frees (MAX_ORDER - X) pages, > however your thread will waste cycles scanning for such. I don't think we need to scan as such. An arch hook that queues a job to a wq only when there's work to do will fix the issue, right? -- MST