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Thu, 16 May 2019 20:19:37 -0400 Received: by mail-pg1-f196.google.com with SMTP id t22so2348996pgi.10 for ; Thu, 16 May 2019 17:19:37 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=grI6nIUF/mMOBdv6LrPvHsdNVES0yai/LfFYIZ4bkWY=; b=trB5X+v2CFHJR5/h5Ogo8pnGEbixSq/5SbMCfW0BvmcDG2zeRdzxHL4lknPMI8JsaG 91o9aNowjUtiTckfyBLWY/pZJBmRERl33EcI9dq0zR0lXd+XHl45wImJtwD6qTmBiD3C YvIdILOfNr02D208IUOgX7xjB1B80gLQERVK/akSkqvFqS79gmXpU/duephS4OxkvMCj iFkaZbcWb+04sJYfOvlYsPNWM7LK/oP8HkDOryS8f1XdKVoMLZUlQ8YVZMbBQiMDnraB fYXacmGWn0btEdYeftIv0rPSsHpeCBXpkkAwnfL+k2zqdhfQJ6WS6TGQ7DeGxI98ZyT1 d5aw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=grI6nIUF/mMOBdv6LrPvHsdNVES0yai/LfFYIZ4bkWY=; b=sBg7Qom3ti9MasV/smTzGTmkH3aXD1xyI9uzCnmBLdBJNQmxP71Ezqj+sfn3xOqEkO pHPp476l5KZ39XgD3ngwmhsCPa6gSRBNJ0WlWdogBQvceJwh7BrUy5Ug63T+W+01NOeq /O61Xh4gQUQ87FB6QTkjAZzna+dAqCVaoM4jr82kJVcU9gn3o8et2bLFzaDowx2n+I// vCd8RjyEmFF3B/zx3m/qHeFIlh6qOxDuGS5BuOfb1lfddVzqlG2BhjddJkEqzYDEYjg8 uyr9jdN996ZsVUzrL0pGg3y+9xuLsJWXMz6xw+Sl2jwudLJ+ZYRYHUXs+OFOCXDZrbSj QMIw== X-Gm-Message-State: APjAAAVQ4p+Q3DbSSnrBXlaEtyAvPC/h1kjmWTdHFz+FBbwyUQsGz/nt I9ksA84ZwpAW4GFhAJbJNSnraQ== X-Google-Smtp-Source: APXvYqyv1iVBQbL6jyOdYGu6UtPQiwVBUuqofcSXUoK/ck1DMyLzSDgzGJaT2Ro5WErOmsiHR9V/gQ== X-Received: by 2002:a63:d816:: with SMTP id b22mr52619479pgh.16.1558051959951; Thu, 16 May 2019 17:12:39 -0700 (PDT) Received: from jstaron2.mtv.corp.google.com ([2620:15c:202:201:b94f:2527:c39f:ca2d]) by smtp.gmail.com with ESMTPSA id a6sm7245768pgd.67.2019.05.16.17.12.37 (version=TLS1_3 cipher=AEAD-AES128-GCM-SHA256 bits=128/128); Thu, 16 May 2019 17:12:39 -0700 (PDT) Subject: Re: [PATCH v9 2/7] virtio-pmem: Add virtio pmem driver To: Pankaj Gupta , linux-nvdimm@lists.01.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, kvm@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-acpi@vger.kernel.org, qemu-devel@nongnu.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org Cc: dan.j.williams@intel.com, zwisler@kernel.org, vishal.l.verma@intel.com, dave.jiang@intel.com, mst@redhat.com, jasowang@redhat.com, willy@infradead.org, rjw@rjwysocki.net, hch@infradead.org, lenb@kernel.org, jack@suse.cz, tytso@mit.edu, adilger.kernel@dilger.ca, darrick.wong@oracle.com, lcapitulino@redhat.com, kwolf@redhat.com, imammedo@redhat.com, jmoyer@redhat.com, nilal@redhat.com, riel@surriel.com, stefanha@redhat.com, aarcange@redhat.com, david@redhat.com, david@fromorbit.com, cohuck@redhat.com, xiaoguangrong.eric@gmail.com, pbonzini@redhat.com, kilobyte@angband.pl, yuval.shaia@oracle.com, smbarber@google.com References: <20190514145422.16923-1-pagupta@redhat.com> <20190514145422.16923-3-pagupta@redhat.com> From: =?UTF-8?Q?Jakub_Staro=c5=84?= Message-ID: Date: Thu, 16 May 2019 17:12:36 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <20190514145422.16923-3-pagupta@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 5/14/19 7:54 AM, Pankaj Gupta wrote: > + if (!list_empty(&vpmem->req_list)) { > + req_buf = list_first_entry(&vpmem->req_list, > + struct virtio_pmem_request, list); > + req_buf->wq_buf_avail = true; > + wake_up(&req_buf->wq_buf); > + list_del(&req_buf->list); Yes, this change is the right one, thank you! > + /* > + * If virtqueue_add_sgs returns -ENOSPC then req_vq virtual > + * queue does not have free descriptor. We add the request > + * to req_list and wait for host_ack to wake us up when free > + * slots are available. > + */ > + while ((err = virtqueue_add_sgs(vpmem->req_vq, sgs, 1, 1, req, > + GFP_ATOMIC)) == -ENOSPC) { > + > + dev_err(&vdev->dev, "failed to send command to virtio pmem" \ > + "device, no free slots in the virtqueue\n"); > + req->wq_buf_avail = false; > + list_add_tail(&req->list, &vpmem->req_list); > + spin_unlock_irqrestore(&vpmem->pmem_lock, flags); > + > + /* A host response results in "host_ack" getting called */ > + wait_event(req->wq_buf, req->wq_buf_avail); > + spin_lock_irqsave(&vpmem->pmem_lock, flags); > + } > + err1 = virtqueue_kick(vpmem->req_vq); > + spin_unlock_irqrestore(&vpmem->pmem_lock, flags); > + > + /* > + * virtqueue_add_sgs failed with error different than -ENOSPC, we can't > + * do anything about that. > + */ > + if (err || !err1) { > + dev_info(&vdev->dev, "failed to send command to virtio pmem device\n"); > + err = -EIO; > + } else { > + /* A host repsonse results in "host_ack" getting called */ > + wait_event(req->host_acked, req->done); > + err = req->ret; > +I confirm that the failures I was facing with the `-ENOSPC` error path are not present in v9. Best, Jakub Staron