From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-oi0-f72.google.com (mail-oi0-f72.google.com [209.85.218.72]) by kanga.kvack.org (Postfix) with ESMTP id 43D396B0038 for ; Sat, 21 Oct 2017 23:20:00 -0400 (EDT) Received: by mail-oi0-f72.google.com with SMTP id 82so14920052oid.11 for ; Sat, 21 Oct 2017 20:20:00 -0700 (PDT) Received: from mx1.redhat.com (mx1.redhat.com. [209.132.183.28]) by mx.google.com with ESMTPS id 2si1408693oto.537.2017.10.21.20.19.58 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sat, 21 Oct 2017 20:19:58 -0700 (PDT) Date: Sun, 22 Oct 2017 06:19:56 +0300 From: "Michael S. Tsirkin" Subject: Re: [PATCH v1 0/3] Virtio-balloon Improvement Message-ID: <20171022061307-mutt-send-email-mst@kernel.org> References: <1508500466-21165-1-git-send-email-wei.w.wang@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1508500466-21165-1-git-send-email-wei.w.wang@intel.com> Sender: owner-linux-mm@kvack.org List-ID: To: Wei Wang Cc: penguin-kernel@I-love.SAKURA.ne.jp, mhocko@kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, virtualization@lists.linux-foundation.org On Fri, Oct 20, 2017 at 07:54:23PM +0800, Wei Wang wrote: > This patch series intends to summarize the recent contributions made by > Michael S. Tsirkin, Tetsuo Handa, Michal Hocko etc. via reporting and > discussing the related deadlock issues on the mailinglist. Please check > each patch for details. > > >From a high-level point of view, this patch series achieves: > 1) eliminate the deadlock issue fundamentally caused by the inability > to run leak_balloon and fill_balloon concurrently; We need to think about this carefully. Is it an issue that leak can now bypass fill? It seems that we can now try to leak a page before fill was seen by host, but I did not look into it deeply. I really like my patch for this better at least for current kernel. I agree we need to work more on 2+3. > 2) enable OOM to release more than 256 inflated pages; and Does just this help enough? How about my patch + 2? Tetsuo, what do you think? > 3) stop inflating when the guest is under severe memory pressure > (i.e. OOM). But when do we finally inflate? Question is how does host know it needs to resend an interrupt, and when should it do it? > Here is an example of the benefit brought by this patch series: > The guest sets virtio_balloon.oom_pages=100000. When the host requests > to inflate 7.9G of an 8G idle guest, the guest can still run normally > since OOM can guarantee at least 100000 pages (400MB) for the guest. > Without the above patches, the guest will kill all the killable > processes and fall into kernel panic finally. > > Wei Wang (3): > virtio-balloon: replace the coarse-grained balloon_lock > virtio-balloon: deflate up to oom_pages on OOM > virtio-balloon: stop inflating when OOM occurs > > drivers/virtio/virtio_balloon.c | 149 ++++++++++++++++++++++++---------------- > 1 file changed, 91 insertions(+), 58 deletions(-) > > -- > 2.7.4 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org