From: Stefano Garzarella <sgarzare@redhat.com> To: Xianting Tian <xianting.tian@linux.alibaba.com> Cc: virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, mst@redhat.com Subject: Re: [PATCH 2/2] virtio_ring: add unlikely annotation for free descs check Date: Tue, 29 Mar 2022 09:50:24 +0200 [thread overview] Message-ID: <20220329075024.eoajm5ufrcfytug4@sgarzare-redhat> (raw) In-Reply-To: <20220328105817.1028065-2-xianting.tian@linux.alibaba.com> On Mon, Mar 28, 2022 at 06:58:17PM +0800, Xianting Tian wrote: >The 'if (vq->vq.num_free < descs_used)' check will almost always be false. > >Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> >--- > drivers/virtio/virtio_ring.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> > >diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c >index d597fc0874ec..ab6d5f0cb579 100644 >--- a/drivers/virtio/virtio_ring.c >+++ b/drivers/virtio/virtio_ring.c >@@ -525,7 +525,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, > descs_used = total_sg; > } > >- if (vq->vq.num_free < descs_used) { >+ if (unlikely(vq->vq.num_free < descs_used)) { > pr_debug("Can't add buf len %i - avail = %i\n", > descs_used, vq->vq.num_free); > /* FIXME: for historical reasons, we force a notify here if >-- >2.17.1 > _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization
WARNING: multiple messages have this Message-ID (diff)
From: Stefano Garzarella <sgarzare@redhat.com> To: Xianting Tian <xianting.tian@linux.alibaba.com> Cc: mst@redhat.com, jasowang@redhat.com, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] virtio_ring: add unlikely annotation for free descs check Date: Tue, 29 Mar 2022 09:50:24 +0200 [thread overview] Message-ID: <20220329075024.eoajm5ufrcfytug4@sgarzare-redhat> (raw) In-Reply-To: <20220328105817.1028065-2-xianting.tian@linux.alibaba.com> On Mon, Mar 28, 2022 at 06:58:17PM +0800, Xianting Tian wrote: >The 'if (vq->vq.num_free < descs_used)' check will almost always be false. > >Signed-off-by: Xianting Tian <xianting.tian@linux.alibaba.com> >--- > drivers/virtio/virtio_ring.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> > >diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c >index d597fc0874ec..ab6d5f0cb579 100644 >--- a/drivers/virtio/virtio_ring.c >+++ b/drivers/virtio/virtio_ring.c >@@ -525,7 +525,7 @@ static inline int virtqueue_add_split(struct virtqueue *_vq, > descs_used = total_sg; > } > >- if (vq->vq.num_free < descs_used) { >+ if (unlikely(vq->vq.num_free < descs_used)) { > pr_debug("Can't add buf len %i - avail = %i\n", > descs_used, vq->vq.num_free); > /* FIXME: for historical reasons, we force a notify here if >-- >2.17.1 >
next prev parent reply other threads:[~2022-03-29 7:50 UTC|newest] Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-03-28 10:58 [PATCH 1/2] virtio_ring: remove unnecessary to_vvq call in vring hot path Xianting Tian 2022-03-28 10:58 ` [PATCH 2/2] virtio_ring: add unlikely annotation for free descs check Xianting Tian 2022-03-29 4:57 ` Jason Wang 2022-03-29 4:57 ` Jason Wang 2022-03-29 7:50 ` Stefano Garzarella [this message] 2022-03-29 7:50 ` Stefano Garzarella 2022-04-04 15:11 ` Xianting Tian 2022-04-04 16:27 ` Michael S. Tsirkin 2022-04-04 16:27 ` Michael S. Tsirkin 2022-03-29 4:56 ` [PATCH 1/2] virtio_ring: remove unnecessary to_vvq call in vring hot path Jason Wang 2022-03-29 4:56 ` Jason Wang 2022-03-29 7:49 ` Stefano Garzarella 2022-03-29 7:49 ` Stefano Garzarella
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20220329075024.eoajm5ufrcfytug4@sgarzare-redhat \ --to=sgarzare@redhat.com \ --cc=linux-kernel@vger.kernel.org \ --cc=mst@redhat.com \ --cc=virtualization@lists.linux-foundation.org \ --cc=xianting.tian@linux.alibaba.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.