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[209.85.220.65]) by mx.google.com with SMTPS id k39sor10436889qvf.59.2019.04.02.10.53.16 for (Google Transport Security); Tue, 02 Apr 2019 10:53:16 -0700 (PDT) Received-SPF: pass (google.com: domain of mst@redhat.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; spf=pass (google.com: domain of mst@redhat.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=mst@redhat.com; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=redhat.com 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: X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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