From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: virtio-dev-return-3059-cohuck=redhat.com@lists.oasis-open.org Sender: List-Post: List-Help: List-Unsubscribe: List-Subscribe: Received: from lists.oasis-open.org (oasis-open.org [66.179.20.138]) by lists.oasis-open.org (Postfix) with ESMTP id 71AE758191AB for ; Thu, 25 Jan 2018 01:42:49 -0800 (PST) Message-ID: <5A69A72F.4000104@intel.com> Date: Thu, 25 Jan 2018 17:45:19 +0800 From: Wei Wang MIME-Version: 1.0 References: <1516790562-37889-1-git-send-email-wei.w.wang@intel.com> <1516790562-37889-3-git-send-email-wei.w.wang@intel.com> <20180124183349-mutt-send-email-mst@kernel.org> In-Reply-To: <20180124183349-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: [virtio-dev] Re: [PATCH v24 2/2] virtio-balloon: VIRTIO_BALLOON_F_FREE_PAGE_HINT To: "Michael S. Tsirkin" Cc: virtio-dev@lists.oasis-open.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-mm@kvack.org, mhocko@kernel.org, akpm@linux-foundation.org, pbonzini@redhat.com, liliang.opensource@gmail.com, yang.zhang.wz@gmail.com, quan.xu0@gmail.com, nilal@redhat.com, riel@redhat.com List-ID: On 01/25/2018 01:15 AM, Michael S. Tsirkin wrote: > On Wed, Jan 24, 2018 at 06:42:42PM +0800, Wei Wang wrote: >> >> >> What is this doing? Basically handling the case where vq is broken? >> It's kind of ugly to tweak feature bits, most code assumes they never >> change. Please just return an error to caller instead and handle it >> there. >> >> You can then avoid sprinking the check for the feature bit >> all over the code. >> > > One thing I don't like about this one is that the previous request > will still try to run to completion. > > And it all seems pretty complex. > > How about: > - pass cmd id to a queued work > - queued work gets that cmd id, stores a copy and uses that, > re-checking periodically - stop if cmd id changes: > will replace report_free_page too since that's set to > stop. > > This means you do not reuse the queued cmd id also > for the buffer - which is probably for the best. Thanks for the suggestion. Please have a check how it's implemented in v25. Just a little reminder that work queue has internally ensured that there is no re-entrant of the same queued function. Best, Wei --------------------------------------------------------------------- To unsubscribe, e-mail: virtio-dev-unsubscribe@lists.oasis-open.org For additional commands, e-mail: virtio-dev-help@lists.oasis-open.org