From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759051Ab3BTKKY (ORCPT ); Wed, 20 Feb 2013 05:10:24 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:29929 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1758854Ab3BTKKV (ORCPT ); Wed, 20 Feb 2013 05:10:21 -0500 X-IronPort-AV: E=Sophos;i="4.84,700,1355068800"; d="scan'208";a="6735911" Message-ID: <5124A0CF.3070104@cn.fujitsu.com> Date: Wed, 20 Feb 2013 18:09:19 +0800 From: Wanlong Gao Reply-To: gaowanlong@cn.fujitsu.com Organization: Fujitsu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: Rusty Russell CC: Paolo Bonzini , virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, "Michael S. Tsirkin" Subject: Re: [PATCH 07/16] virtio_ring: don't count elements twice for add_buf path. References: <1361260594-601-1-git-send-email-rusty@rustcorp.com.au> <1361260594-601-8-git-send-email-rusty@rustcorp.com.au> In-Reply-To: <1361260594-601-8-git-send-email-rusty@rustcorp.com.au> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/02/20 18:09:38, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2013/02/20 18:09:39, Serialize complete at 2013/02/20 18:09:39 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/19/2013 03:56 PM, Rusty Russell wrote: > Extract the post-counting code into virtqueue_add(), make both callers > use it. > > Signed-off-by: Rusty Russell Reviewed-by: Wanlong Gao > --- > drivers/virtio/virtio_ring.c | 147 +++++++++++++++++++++++------------------- > 1 file changed, 80 insertions(+), 67 deletions(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index 27e31d3..c537385 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -163,69 +163,17 @@ static int vring_add_indirect(struct vring_virtqueue *vq, > return head; > } > > -/** > - * virtqueue_add_buf - expose buffer to other end > - * @vq: the struct virtqueue we're talking about. > - * @sg: the description of the buffer(s). > - * @out_num: the number of sg readable by other side > - * @in_num: the number of sg which are writable (after readable ones) > - * @data: the token identifying the buffer. > - * @gfp: how to do memory allocations (if necessary). > - * > - * Caller must ensure we don't call this with other virtqueue operations > - * at the same time (except where noted). > - * > - * Returns zero or a negative error (ie. ENOSPC, ENOMEM). > - */ > -int virtqueue_add_buf(struct virtqueue *_vq, > - struct scatterlist sg[], > - unsigned int out, > - unsigned int in, > - void *data, > - gfp_t gfp) > -{ > - struct scatterlist *sgs[2]; > - unsigned int i; > - > - sgs[0] = sg; > - sgs[1] = sg + out; > - > - /* Workaround until callers pass well-formed sgs. */ > - for (i = 0; i < out + in; i++) > - sg_unmark_end(sg + i); > - > - sg_mark_end(sg + out + in - 1); > - if (out && in) > - sg_mark_end(sg + out - 1); > - > - return virtqueue_add_sgs(_vq, sgs, out ? 1 : 0, in ? 1 : 0, data, gfp); > -} > -EXPORT_SYMBOL_GPL(virtqueue_add_buf); > - > -/** > - * virtqueue_add_sgs - expose buffers to other end > - * @vq: the struct virtqueue we're talking about. > - * @sgs: array of terminated scatterlists. > - * @out_num: the number of scatterlists readable by other side > - * @in_num: the number of scatterlists which are writable (after readable ones) > - * @data: the token identifying the buffer. > - * @gfp: how to do memory allocations (if necessary). > - * > - * Caller must ensure we don't call this with other virtqueue operations > - * at the same time (except where noted). > - * > - * Returns zero or a negative error (ie. ENOSPC, ENOMEM). > - */ > -int virtqueue_add_sgs(struct virtqueue *_vq, > - struct scatterlist *sgs[], > - unsigned int out_sgs, > - unsigned int in_sgs, > - void *data, > - gfp_t gfp) > +static int virtqueue_add(struct virtqueue *_vq, > + struct scatterlist *sgs[], > + unsigned int total_sg, > + unsigned int out_sgs, > + unsigned int in_sgs, > + void *data, > + gfp_t gfp) > { > struct vring_virtqueue *vq = to_vvq(_vq); > struct scatterlist *sg; > - unsigned int i, n, avail, uninitialized_var(prev), total_sg; > + unsigned int i, n, avail, uninitialized_var(prev); > int head; > > START_USE(vq); > @@ -245,13 +193,6 @@ int virtqueue_add_sgs(struct virtqueue *_vq, > } > #endif > > - /* Count them first. */ > - for (i = total_sg = 0; i < out_sgs + in_sgs; i++) { > - struct scatterlist *sg; > - for (sg = sgs[i]; sg; sg = sg_next(sg)) > - total_sg++; > - } > - > /* If the host supports indirect descriptor tables, and we have multiple > * buffers, then go indirect. FIXME: tune this threshold */ > if (vq->indirect && total_sg > 1 && vq->vq.num_free) { > @@ -329,6 +270,78 @@ add_head: > > return 0; > } > + > +/** > + * virtqueue_add_buf - expose buffer to other end > + * @vq: the struct virtqueue we're talking about. > + * @sg: the description of the buffer(s). > + * @out_num: the number of sg readable by other side > + * @in_num: the number of sg which are writable (after readable ones) > + * @data: the token identifying the buffer. > + * @gfp: how to do memory allocations (if necessary). > + * > + * Caller must ensure we don't call this with other virtqueue operations > + * at the same time (except where noted). > + * > + * Returns zero or a negative error (ie. ENOSPC, ENOMEM). > + */ > +int virtqueue_add_buf(struct virtqueue *_vq, > + struct scatterlist sg[], > + unsigned int out, > + unsigned int in, > + void *data, > + gfp_t gfp) > +{ > + struct scatterlist *sgs[2]; > + unsigned int i; > + > + sgs[0] = sg; > + sgs[1] = sg + out; > + > + /* Workaround until callers pass well-formed sgs. */ > + for (i = 0; i < out + in; i++) > + sg_unmark_end(sg + i); > + > + sg_mark_end(sg + out + in - 1); > + if (out && in) > + sg_mark_end(sg + out - 1); > + > + return virtqueue_add(_vq, sgs, out+in, out ? 1 : 0, in ? 1 : 0, > + data, gfp); > +} > +EXPORT_SYMBOL_GPL(virtqueue_add_buf); > + > +/** > + * virtqueue_add_sgs - expose buffers to other end > + * @vq: the struct virtqueue we're talking about. > + * @sgs: array of terminated scatterlists. > + * @out_num: the number of scatterlists readable by other side > + * @in_num: the number of scatterlists which are writable (after readable ones) > + * @data: the token identifying the buffer. > + * @gfp: how to do memory allocations (if necessary). > + * > + * Caller must ensure we don't call this with other virtqueue operations > + * at the same time (except where noted). > + * > + * Returns zero or a negative error (ie. ENOSPC, ENOMEM). > + */ > +int virtqueue_add_sgs(struct virtqueue *_vq, > + struct scatterlist *sgs[], > + unsigned int out_sgs, > + unsigned int in_sgs, > + void *data, > + gfp_t gfp) > +{ > + unsigned int i, total_sg; > + > + /* Count them first. */ > + for (i = total_sg = 0; i < out_sgs + in_sgs; i++) { > + struct scatterlist *sg; > + for (sg = sgs[i]; sg; sg = sg_next(sg)) > + total_sg++; > + } > + return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs, data, gfp); > +} > EXPORT_SYMBOL_GPL(virtqueue_add_sgs); > > /** > From mboxrd@z Thu Jan 1 00:00:00 1970 From: Wanlong Gao Subject: Re: [PATCH 07/16] virtio_ring: don't count elements twice for add_buf path. Date: Wed, 20 Feb 2013 18:09:19 +0800 Message-ID: <5124A0CF.3070104@cn.fujitsu.com> References: <1361260594-601-1-git-send-email-rusty@rustcorp.com.au> <1361260594-601-8-git-send-email-rusty@rustcorp.com.au> Reply-To: gaowanlong@cn.fujitsu.com Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1361260594-601-8-git-send-email-rusty@rustcorp.com.au> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: Rusty Russell Cc: Paolo Bonzini , "Michael S. Tsirkin" , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org On 02/19/2013 03:56 PM, Rusty Russell wrote: > Extract the post-counting code into virtqueue_add(), make both callers > use it. > > Signed-off-by: Rusty Russell Reviewed-by: Wanlong Gao > --- > drivers/virtio/virtio_ring.c | 147 +++++++++++++++++++++++------------------- > 1 file changed, 80 insertions(+), 67 deletions(-) > > diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c > index 27e31d3..c537385 100644 > --- a/drivers/virtio/virtio_ring.c > +++ b/drivers/virtio/virtio_ring.c > @@ -163,69 +163,17 @@ static int vring_add_indirect(struct vring_virtqueue *vq, > return head; > } > > -/** > - * virtqueue_add_buf - expose buffer to other end > - * @vq: the struct virtqueue we're talking about. > - * @sg: the description of the buffer(s). > - * @out_num: the number of sg readable by other side > - * @in_num: the number of sg which are writable (after readable ones) > - * @data: the token identifying the buffer. > - * @gfp: how to do memory allocations (if necessary). > - * > - * Caller must ensure we don't call this with other virtqueue operations > - * at the same time (except where noted). > - * > - * Returns zero or a negative error (ie. ENOSPC, ENOMEM). > - */ > -int virtqueue_add_buf(struct virtqueue *_vq, > - struct scatterlist sg[], > - unsigned int out, > - unsigned int in, > - void *data, > - gfp_t gfp) > -{ > - struct scatterlist *sgs[2]; > - unsigned int i; > - > - sgs[0] = sg; > - sgs[1] = sg + out; > - > - /* Workaround until callers pass well-formed sgs. */ > - for (i = 0; i < out + in; i++) > - sg_unmark_end(sg + i); > - > - sg_mark_end(sg + out + in - 1); > - if (out && in) > - sg_mark_end(sg + out - 1); > - > - return virtqueue_add_sgs(_vq, sgs, out ? 1 : 0, in ? 1 : 0, data, gfp); > -} > -EXPORT_SYMBOL_GPL(virtqueue_add_buf); > - > -/** > - * virtqueue_add_sgs - expose buffers to other end > - * @vq: the struct virtqueue we're talking about. > - * @sgs: array of terminated scatterlists. > - * @out_num: the number of scatterlists readable by other side > - * @in_num: the number of scatterlists which are writable (after readable ones) > - * @data: the token identifying the buffer. > - * @gfp: how to do memory allocations (if necessary). > - * > - * Caller must ensure we don't call this with other virtqueue operations > - * at the same time (except where noted). > - * > - * Returns zero or a negative error (ie. ENOSPC, ENOMEM). > - */ > -int virtqueue_add_sgs(struct virtqueue *_vq, > - struct scatterlist *sgs[], > - unsigned int out_sgs, > - unsigned int in_sgs, > - void *data, > - gfp_t gfp) > +static int virtqueue_add(struct virtqueue *_vq, > + struct scatterlist *sgs[], > + unsigned int total_sg, > + unsigned int out_sgs, > + unsigned int in_sgs, > + void *data, > + gfp_t gfp) > { > struct vring_virtqueue *vq = to_vvq(_vq); > struct scatterlist *sg; > - unsigned int i, n, avail, uninitialized_var(prev), total_sg; > + unsigned int i, n, avail, uninitialized_var(prev); > int head; > > START_USE(vq); > @@ -245,13 +193,6 @@ int virtqueue_add_sgs(struct virtqueue *_vq, > } > #endif > > - /* Count them first. */ > - for (i = total_sg = 0; i < out_sgs + in_sgs; i++) { > - struct scatterlist *sg; > - for (sg = sgs[i]; sg; sg = sg_next(sg)) > - total_sg++; > - } > - > /* If the host supports indirect descriptor tables, and we have multiple > * buffers, then go indirect. FIXME: tune this threshold */ > if (vq->indirect && total_sg > 1 && vq->vq.num_free) { > @@ -329,6 +270,78 @@ add_head: > > return 0; > } > + > +/** > + * virtqueue_add_buf - expose buffer to other end > + * @vq: the struct virtqueue we're talking about. > + * @sg: the description of the buffer(s). > + * @out_num: the number of sg readable by other side > + * @in_num: the number of sg which are writable (after readable ones) > + * @data: the token identifying the buffer. > + * @gfp: how to do memory allocations (if necessary). > + * > + * Caller must ensure we don't call this with other virtqueue operations > + * at the same time (except where noted). > + * > + * Returns zero or a negative error (ie. ENOSPC, ENOMEM). > + */ > +int virtqueue_add_buf(struct virtqueue *_vq, > + struct scatterlist sg[], > + unsigned int out, > + unsigned int in, > + void *data, > + gfp_t gfp) > +{ > + struct scatterlist *sgs[2]; > + unsigned int i; > + > + sgs[0] = sg; > + sgs[1] = sg + out; > + > + /* Workaround until callers pass well-formed sgs. */ > + for (i = 0; i < out + in; i++) > + sg_unmark_end(sg + i); > + > + sg_mark_end(sg + out + in - 1); > + if (out && in) > + sg_mark_end(sg + out - 1); > + > + return virtqueue_add(_vq, sgs, out+in, out ? 1 : 0, in ? 1 : 0, > + data, gfp); > +} > +EXPORT_SYMBOL_GPL(virtqueue_add_buf); > + > +/** > + * virtqueue_add_sgs - expose buffers to other end > + * @vq: the struct virtqueue we're talking about. > + * @sgs: array of terminated scatterlists. > + * @out_num: the number of scatterlists readable by other side > + * @in_num: the number of scatterlists which are writable (after readable ones) > + * @data: the token identifying the buffer. > + * @gfp: how to do memory allocations (if necessary). > + * > + * Caller must ensure we don't call this with other virtqueue operations > + * at the same time (except where noted). > + * > + * Returns zero or a negative error (ie. ENOSPC, ENOMEM). > + */ > +int virtqueue_add_sgs(struct virtqueue *_vq, > + struct scatterlist *sgs[], > + unsigned int out_sgs, > + unsigned int in_sgs, > + void *data, > + gfp_t gfp) > +{ > + unsigned int i, total_sg; > + > + /* Count them first. */ > + for (i = total_sg = 0; i < out_sgs + in_sgs; i++) { > + struct scatterlist *sg; > + for (sg = sgs[i]; sg; sg = sg_next(sg)) > + total_sg++; > + } > + return virtqueue_add(_vq, sgs, total_sg, out_sgs, in_sgs, data, gfp); > +} > EXPORT_SYMBOL_GPL(virtqueue_add_sgs); > > /** >