Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758017Ab2KAXXN (ORCPT ); Thu, 1 Nov 2012 19:23:13 -0400 Received: from ozlabs.org ([203.10.76.45]:33941 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751552Ab2KAXXK convert rfc822-to-8bit (ORCPT ); Thu, 1 Nov 2012 19:23:10 -0400 From: Rusty Russell To: Amit Shah Cc: sjur.brandeland@stericsson.com, "Michael S. Tsirkin" , Linus Walleij , Masami Hiramatsu , Ohad Ben-Cohen , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org, sjurbren@gmail.com Subject: Re: [PATCHv7 4/4] virtio_console: Add support for remoteproc serial In-Reply-To: <20121101073951.GA17012@amit.redhat.com> References: <1350287856-5284-1-git-send-email-sjur.brandeland@stericsson.com> <1350287856-5284-5-git-send-email-sjur.brandeland@stericsson.com> <878vayhsca.fsf@rustcorp.com.au> <20121101073951.GA17012@amit.redhat.com> User-Agent: Notmuch/0.14 (http://notmuchmail.org) Emacs/23.4.1 (i686-pc-linux-gnu) Date: Fri, 02 Nov 2012 09:52:08 +1030 Message-ID: <87r4oc52ov.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1979 Lines: 57 Amit Shah writes: > On (Tue) 23 Oct 2012 [12:17:49], Rusty Russell wrote: >> sjur.brandeland@stericsson.com writes: >> > From: Sjur Brændeland > >> > @@ -1415,7 +1524,16 @@ static void remove_port_data(struct port *port) >> > >> > /* Remove buffers we queued up for the Host to send us data in. */ >> > while ((buf = virtqueue_detach_unused_buf(port->in_vq))) >> > - free_buf(buf); >> > + free_buf(buf, true); >> > + >> > + /* >> > + * Remove buffers from out queue for rproc-serial. We cannot afford >> > + * to leak any DMA mem, so reclaim this memory even if this might be >> > + * racy for the remote processor. >> > + */ >> > + if (is_rproc_serial(port->portdev->vdev)) >> > + while ((buf = virtqueue_detach_unused_buf(port->out_vq))) >> > + free_buf(buf, true); >> > } >> >> This seems wrong; either this is needed even if !is_rproc_serial(), or >> it's not necessary as the out_vq is empty. >> >> Every path I can see has the device reset (in which case the queues >> should not be active), or we got a VIRTIO_CONSOLE_PORT_REMOVE event (in >> which case, the same). >> >> I think we can have non-blocking writes which could leave buffers in >> out_vq: Amit? > > Those get 'reclaimed' just above this hunk: > > > static void remove_port_data(struct port *port) > { > struct port_buffer *buf; > > /* Remove unused data this port might have received. */ > discard_port_data(port); > > reclaim_consumed_buffers(port); > > /* Remove buffers we queued up for the Host to send us data in. */ > while ((buf = virtqueue_detach_unused_buf(port->in_vq))) > free_buf(buf, true); No, that's pending input buffers, not output buffers. Cheers, Rusty. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/