We use ioat ring space for determining if ioat callbacks can enqueue a packet to ioat device. But there is one slot can't be used in ioat ring due to the ioat driver design, so we need to reduce one slot in ioat ring to prevent ring size mismatch in ioat callbacks. Fixes: 2aa47e94bfb2 ("examples/vhost: add ioat ring space count and check") Cc: stable@dpdk.org Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com> --- examples/vhost/ioat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/examples/vhost/ioat.c b/examples/vhost/ioat.c index 60b73be93..9cb5e0d50 100644 --- a/examples/vhost/ioat.c +++ b/examples/vhost/ioat.c @@ -113,7 +113,7 @@ open_ioat(const char *value) goto out; } rte_rawdev_start(dev_id); - cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE; + cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE - 1; dma_info->nr++; i++; } -- 2.29.2
Reviewed-by: Jiayu Hu <jiayu.hu@intel.com>
> -----Original Message-----
> From: Jiang, Cheng1 <cheng1.jiang@intel.com>
> Sent: Wednesday, March 17, 2021 1:41 PM
> To: maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
> Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; Yang, YvonneX
> <yvonnex.yang@intel.com>; Wang, Yinan <yinan.wang@intel.com>; Jiang,
> Cheng1 <cheng1.jiang@intel.com>; stable@dpdk.org
> Subject: [PATCH] examples/vhost: fix ioat ring space in callbacks
>
> We use ioat ring space for determining if ioat callbacks can enqueue a
> packet to ioat device. But there is one slot can't be used in ioat
> ring due to the ioat driver design, so we need to reduce one slot in
> ioat ring to prevent ring size mismatch in ioat callbacks.
>
> Fixes: 2aa47e94bfb2 ("examples/vhost: add ioat ring space count and check")
> Cc: stable@dpdk.org
>
> Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
> ---
> examples/vhost/ioat.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/examples/vhost/ioat.c b/examples/vhost/ioat.c
> index 60b73be93..9cb5e0d50 100644
> --- a/examples/vhost/ioat.c
> +++ b/examples/vhost/ioat.c
> @@ -113,7 +113,7 @@ open_ioat(const char *value)
> goto out;
> }
> rte_rawdev_start(dev_id);
> - cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE;
> + cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE - 1;
> dma_info->nr++;
> i++;
> }
> --
> 2.29.2
On 3/17/21 6:40 AM, Cheng Jiang wrote: > We use ioat ring space for determining if ioat callbacks can enqueue a > packet to ioat device. But there is one slot can't be used in ioat > ring due to the ioat driver design, so we need to reduce one slot in > ioat ring to prevent ring size mismatch in ioat callbacks. > > Fixes: 2aa47e94bfb2 ("examples/vhost: add ioat ring space count and check") > Cc: stable@dpdk.org > > Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com> > --- > examples/vhost/ioat.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/examples/vhost/ioat.c b/examples/vhost/ioat.c > index 60b73be93..9cb5e0d50 100644 > --- a/examples/vhost/ioat.c > +++ b/examples/vhost/ioat.c > @@ -113,7 +113,7 @@ open_ioat(const char *value) > goto out; > } > rte_rawdev_start(dev_id); > - cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE; > + cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE - 1; That really comforts me in thinking we need a generic abstraction for DMA devices. How is the application developer supposed to know that the DMA driver has such weird limitations? Can the driver be fixed to have a proper behavior? > dma_info->nr++; > i++; > } >
Hi Maxime, > -----Original Message----- > From: Maxime Coquelin <maxime.coquelin@redhat.com> > Sent: Wednesday, April 7, 2021 3:48 PM > To: Jiang, Cheng1 <cheng1.jiang@intel.com>; Xia, Chenbo > <chenbo.xia@intel.com>; Thomas Monjalon <thomas@monjalon.net> > Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; Yang, YvonneX > <yvonnex.yang@intel.com>; Wang, Yinan <yinan.wang@intel.com>; > stable@dpdk.org > Subject: Re: [PATCH] examples/vhost: fix ioat ring space in callbacks > > > > On 3/17/21 6:40 AM, Cheng Jiang wrote: > > We use ioat ring space for determining if ioat callbacks can enqueue a > > packet to ioat device. But there is one slot can't be used in ioat > > ring due to the ioat driver design, so we need to reduce one slot in > > ioat ring to prevent ring size mismatch in ioat callbacks. > > > > Fixes: 2aa47e94bfb2 ("examples/vhost: add ioat ring space count and > check") > > Cc: stable@dpdk.org > > > > Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com> > > --- > > examples/vhost/ioat.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/examples/vhost/ioat.c b/examples/vhost/ioat.c > > index 60b73be93..9cb5e0d50 100644 > > --- a/examples/vhost/ioat.c > > +++ b/examples/vhost/ioat.c > > @@ -113,7 +113,7 @@ open_ioat(const char *value) > > goto out; > > } > > rte_rawdev_start(dev_id); > > - cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE; > > + cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE - 1; > > That really comforts me in thinking we need a generic abstraction for > DMA devices. How is the application developer supposed to know that > the DMA driver has such weird limitations? > > Can the driver be fixed to have a proper behavior? Here is the patch of providing capacity check API for DMA: http://patches.dpdk.org/project/dpdk/patch/20210318182042.43658-6-bruce.richardson@intel.com/ Thanks, Jiayu > > > dma_info->nr++; > > i++; > > } > >
On 4/7/21 9:54 AM, Hu, Jiayu wrote: > Hi Maxime, > >> -----Original Message----- >> From: Maxime Coquelin <maxime.coquelin@redhat.com> >> Sent: Wednesday, April 7, 2021 3:48 PM >> To: Jiang, Cheng1 <cheng1.jiang@intel.com>; Xia, Chenbo >> <chenbo.xia@intel.com>; Thomas Monjalon <thomas@monjalon.net> >> Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; Yang, YvonneX >> <yvonnex.yang@intel.com>; Wang, Yinan <yinan.wang@intel.com>; >> stable@dpdk.org >> Subject: Re: [PATCH] examples/vhost: fix ioat ring space in callbacks >> >> >> >> On 3/17/21 6:40 AM, Cheng Jiang wrote: >>> We use ioat ring space for determining if ioat callbacks can enqueue a >>> packet to ioat device. But there is one slot can't be used in ioat >>> ring due to the ioat driver design, so we need to reduce one slot in >>> ioat ring to prevent ring size mismatch in ioat callbacks. >>> >>> Fixes: 2aa47e94bfb2 ("examples/vhost: add ioat ring space count and >> check") >>> Cc: stable@dpdk.org >>> >>> Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com> >>> --- >>> examples/vhost/ioat.c | 2 +- >>> 1 file changed, 1 insertion(+), 1 deletion(-) >>> >>> diff --git a/examples/vhost/ioat.c b/examples/vhost/ioat.c >>> index 60b73be93..9cb5e0d50 100644 >>> --- a/examples/vhost/ioat.c >>> +++ b/examples/vhost/ioat.c >>> @@ -113,7 +113,7 @@ open_ioat(const char *value) >>> goto out; >>> } >>> rte_rawdev_start(dev_id); >>> - cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE; >>> + cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE - 1; >> >> That really comforts me in thinking we need a generic abstraction for >> DMA devices. How is the application developer supposed to know that >> the DMA driver has such weird limitations? >> >> Can the driver be fixed to have a proper behavior? > > Here is the patch of providing capacity check API for DMA: > http://patches.dpdk.org/project/dpdk/patch/20210318182042.43658-6-bruce.richardson@intel.com/ OK, thanks for the pointer. While this new API is being reviewed, and for LTS, let's pick your patch. As soon as Bruce patch is merged, please send a new patch on top to make use of this API. Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com> Thanks, Maxime > Thanks, > Jiayu >> >>> dma_info->nr++; >>> i++; >>> } >>> >
Hi, > -----Original Message----- > From: Maxime Coquelin <maxime.coquelin@redhat.com> > Sent: Tuesday, April 13, 2021 4:51 PM > To: Hu, Jiayu <jiayu.hu@intel.com>; Jiang, Cheng1 <cheng1.jiang@intel.com>; > Xia, Chenbo <chenbo.xia@intel.com>; Thomas Monjalon > <thomas@monjalon.net> > Cc: dev@dpdk.org; Yang, YvonneX <yvonnex.yang@intel.com>; Wang, Yinan > <yinan.wang@intel.com>; stable@dpdk.org > Subject: Re: [PATCH] examples/vhost: fix ioat ring space in callbacks > > > > On 4/7/21 9:54 AM, Hu, Jiayu wrote: > > Hi Maxime, > > > >> -----Original Message----- > >> From: Maxime Coquelin <maxime.coquelin@redhat.com> > >> Sent: Wednesday, April 7, 2021 3:48 PM > >> To: Jiang, Cheng1 <cheng1.jiang@intel.com>; Xia, Chenbo > >> <chenbo.xia@intel.com>; Thomas Monjalon <thomas@monjalon.net> > >> Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; Yang, YvonneX > >> <yvonnex.yang@intel.com>; Wang, Yinan <yinan.wang@intel.com>; > >> stable@dpdk.org > >> Subject: Re: [PATCH] examples/vhost: fix ioat ring space in callbacks > >> > >> > >> > >> On 3/17/21 6:40 AM, Cheng Jiang wrote: > >>> We use ioat ring space for determining if ioat callbacks can enqueue > >>> a packet to ioat device. But there is one slot can't be used in ioat > >>> ring due to the ioat driver design, so we need to reduce one slot in > >>> ioat ring to prevent ring size mismatch in ioat callbacks. > >>> > >>> Fixes: 2aa47e94bfb2 ("examples/vhost: add ioat ring space count and > >> check") > >>> Cc: stable@dpdk.org > >>> > >>> Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com> > >>> --- > >>> examples/vhost/ioat.c | 2 +- > >>> 1 file changed, 1 insertion(+), 1 deletion(-) > >>> > >>> diff --git a/examples/vhost/ioat.c b/examples/vhost/ioat.c index > >>> 60b73be93..9cb5e0d50 100644 > >>> --- a/examples/vhost/ioat.c > >>> +++ b/examples/vhost/ioat.c > >>> @@ -113,7 +113,7 @@ open_ioat(const char *value) > >>> goto out; > >>> } > >>> rte_rawdev_start(dev_id); > >>> - cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE; > >>> + cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE - 1; > >> > >> That really comforts me in thinking we need a generic abstraction for > >> DMA devices. How is the application developer supposed to know that > >> the DMA driver has such weird limitations? > >> > >> Can the driver be fixed to have a proper behavior? > > > > Here is the patch of providing capacity check API for DMA: > > http://patches.dpdk.org/project/dpdk/patch/20210318182042.43658-6- > bruc > > e.richardson@intel.com/ > > OK, thanks for the pointer. > > While this new API is being reviewed, and for LTS, let's pick your patch. As > soon as Bruce patch is merged, please send a new patch on top to make use > of this API. Sure, thanks a lot. Cheng > > Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com> > > Thanks, > Maxime > > > Thanks, > > Jiayu > >> > >>> dma_info->nr++; > >>> i++; > >>> } > >>> > >
> -----Original Message-----
> From: Jiang, Cheng1 <cheng1.jiang@intel.com>
> Sent: Wednesday, March 17, 2021 1:41 PM
> To: maxime.coquelin@redhat.com; Xia, Chenbo <chenbo.xia@intel.com>
> Cc: dev@dpdk.org; Hu, Jiayu <jiayu.hu@intel.com>; Yang, YvonneX
> <yvonnex.yang@intel.com>; Wang, Yinan <yinan.wang@intel.com>; Jiang, Cheng1
> <cheng1.jiang@intel.com>; stable@dpdk.org
> Subject: [PATCH] examples/vhost: fix ioat ring space in callbacks
>
> We use ioat ring space for determining if ioat callbacks can enqueue a
> packet to ioat device. But there is one slot can't be used in ioat
> ring due to the ioat driver design, so we need to reduce one slot in
> ioat ring to prevent ring size mismatch in ioat callbacks.
>
> Fixes: 2aa47e94bfb2 ("examples/vhost: add ioat ring space count and check")
> Cc: stable@dpdk.org
>
> Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
> ---
> examples/vhost/ioat.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/examples/vhost/ioat.c b/examples/vhost/ioat.c
> index 60b73be93..9cb5e0d50 100644
> --- a/examples/vhost/ioat.c
> +++ b/examples/vhost/ioat.c
> @@ -113,7 +113,7 @@ open_ioat(const char *value)
> goto out;
> }
> rte_rawdev_start(dev_id);
> - cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE;
> + cb_tracker[dev_id].ioat_space = IOAT_RING_SIZE - 1;
> dma_info->nr++;
> i++;
> }
> --
> 2.29.2
Patch applied to next-virtio/main, Thanks