* [dpdk-dev] [PATCH] virito: fix reuse index in nested loop @ 2016-06-12 10:05 Jianfeng Tan 2016-06-13 8:57 ` Yuanhan Liu 0 siblings, 1 reply; 4+ messages in thread From: Jianfeng Tan @ 2016-06-12 10:05 UTC (permalink / raw) To: dev; +Cc: yuanhan.liu, huawei.xie, Jianfeng Tan This patches fixes problem of reusing index of outmost loop in nested loops. This bug will lead to failure when starting a multi queue virtio device: rx queues (except from the first one) cannot be started, expecially their vq_ring cannot be initialized, so that when invoking rx func on these queues, segment fault happens. Fixes: a900472aedef ("virtio: split virtio Rx/Tx queue") Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com> --- drivers/net/virtio/virtio_rxtx.c | 36 ++++++++++++++++++++---------------- 1 file changed, 20 insertions(+), 16 deletions(-) diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c index 2e7205b..b96d0cb 100644 --- a/drivers/net/virtio/virtio_rxtx.c +++ b/drivers/net/virtio/virtio_rxtx.c @@ -331,7 +331,7 @@ virtio_dev_rxtx_start(struct rte_eth_dev *dev) * - Allocate blank mbufs for the each rx descriptor * */ - int i; + int i, j; PMD_INIT_FUNC_TRACE(); @@ -352,15 +352,18 @@ virtio_dev_rxtx_start(struct rte_eth_dev *dev) error = ENOSPC; #ifdef RTE_MACHINE_CPUFLAG_SSSE3 - if (use_simple_rxtx) - for (i = 0; i < vq->vq_nentries; i++) { - vq->vq_ring.avail->ring[i] = i; - vq->vq_ring.desc[i].flags = VRING_DESC_F_WRITE; + if (use_simple_rxtx) { + uint16_t k; + + for (k = 0; k < vq->vq_nentries; k++) { + vq->vq_ring.avail->ring[k] = k; + vq->vq_ring.desc[k].flags = VRING_DESC_F_WRITE; } + } #endif memset(&rxvq->fake_mbuf, 0, sizeof(rxvq->fake_mbuf)); - for (i = 0; i < RTE_PMD_VIRTIO_RX_MAX_BURST; i++) - vq->sw_ring[vq->vq_nentries + i] = &rxvq->fake_mbuf; + for (j = 0; j < RTE_PMD_VIRTIO_RX_MAX_BURST; j++) + vq->sw_ring[vq->vq_nentries + j] = &rxvq->fake_mbuf; while (!virtqueue_full(vq)) { m = rte_mbuf_raw_alloc(rxvq->mpool); @@ -399,20 +402,21 @@ virtio_dev_rxtx_start(struct rte_eth_dev *dev) #ifdef RTE_MACHINE_CPUFLAG_SSSE3 if (use_simple_rxtx) { int mid_idx = vq->vq_nentries >> 1; - for (i = 0; i < mid_idx; i++) { - vq->vq_ring.avail->ring[i] = i + mid_idx; - vq->vq_ring.desc[i + mid_idx].next = i; - vq->vq_ring.desc[i + mid_idx].addr = + + for (j = 0; j < mid_idx; j++) { + vq->vq_ring.avail->ring[j] = j + mid_idx; + vq->vq_ring.desc[j + mid_idx].next = j; + vq->vq_ring.desc[j + mid_idx].addr = txvq->virtio_net_hdr_mem + offsetof(struct virtio_tx_region, tx_hdr); - vq->vq_ring.desc[i + mid_idx].len = + vq->vq_ring.desc[j + mid_idx].len = vq->hw->vtnet_hdr_size; - vq->vq_ring.desc[i + mid_idx].flags = + vq->vq_ring.desc[j + mid_idx].flags = VRING_DESC_F_NEXT; - vq->vq_ring.desc[i].flags = 0; + vq->vq_ring.desc[j].flags = 0; } - for (i = mid_idx; i < vq->vq_nentries; i++) - vq->vq_ring.avail->ring[i] = i; + for (j = mid_idx; j < vq->vq_nentries; j++) + vq->vq_ring.avail->ring[j] = j; } #endif VIRTQUEUE_DUMP(vq); -- 2.1.4 ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [dpdk-dev] [PATCH] virito: fix reuse index in nested loop 2016-06-12 10:05 [dpdk-dev] [PATCH] virito: fix reuse index in nested loop Jianfeng Tan @ 2016-06-13 8:57 ` Yuanhan Liu 2016-06-13 9:11 ` Tan, Jianfeng 0 siblings, 1 reply; 4+ messages in thread From: Yuanhan Liu @ 2016-06-13 8:57 UTC (permalink / raw) To: Jianfeng Tan; +Cc: dev, huawei.xie On Sun, Jun 12, 2016 at 10:05:45AM +0000, Jianfeng Tan wrote: > This patches fixes problem of reusing index of outmost loop in nested > loops. This bug will lead to failure when starting a multi queue > virtio device: rx queues (except from the first one) cannot be started, > expecially their vq_ring cannot be initialized, so that when invoking > rx func on these queues, segment fault happens. > > Fixes: a900472aedef ("virtio: split virtio Rx/Tx queue") Good catch! > Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com> > --- > drivers/net/virtio/virtio_rxtx.c | 36 ++++++++++++++++++++---------------- > 1 file changed, 20 insertions(+), 16 deletions(-) > > diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c > index 2e7205b..b96d0cb 100644 > --- a/drivers/net/virtio/virtio_rxtx.c > +++ b/drivers/net/virtio/virtio_rxtx.c > @@ -331,7 +331,7 @@ virtio_dev_rxtx_start(struct rte_eth_dev *dev) > * - Allocate blank mbufs for the each rx descriptor > * > */ > - int i; > + int i, j; However, I don't quite like using "i, j, k" stuff. So, how about renaming "j" to "ring_idx"? > PMD_INIT_FUNC_TRACE(); > > @@ -352,15 +352,18 @@ virtio_dev_rxtx_start(struct rte_eth_dev *dev) > error = ENOSPC; > > #ifdef RTE_MACHINE_CPUFLAG_SSSE3 > - if (use_simple_rxtx) > - for (i = 0; i < vq->vq_nentries; i++) { > - vq->vq_ring.avail->ring[i] = i; > - vq->vq_ring.desc[i].flags = VRING_DESC_F_WRITE; > + if (use_simple_rxtx) { > + uint16_t k; We could reuse "ring_idx" here; no need to define yet another iterate var for that. --yliu ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [dpdk-dev] [PATCH] virito: fix reuse index in nested loop 2016-06-13 8:57 ` Yuanhan Liu @ 2016-06-13 9:11 ` Tan, Jianfeng 2016-06-13 9:31 ` Yuanhan Liu 0 siblings, 1 reply; 4+ messages in thread From: Tan, Jianfeng @ 2016-06-13 9:11 UTC (permalink / raw) To: Yuanhan Liu; +Cc: dev, Xie, Huawei > -----Original Message----- > From: Yuanhan Liu [mailto:yuanhan.liu@linux.intel.com] > Sent: Monday, June 13, 2016 4:58 PM > To: Tan, Jianfeng > Cc: dev@dpdk.org; Xie, Huawei > Subject: Re: [PATCH] virito: fix reuse index in nested loop > > On Sun, Jun 12, 2016 at 10:05:45AM +0000, Jianfeng Tan wrote: > > This patches fixes problem of reusing index of outmost loop in nested > > loops. This bug will lead to failure when starting a multi queue > > virtio device: rx queues (except from the first one) cannot be started, > > expecially their vq_ring cannot be initialized, so that when invoking > > rx func on these queues, segment fault happens. > > > > Fixes: a900472aedef ("virtio: split virtio Rx/Tx queue") > > Good catch! > > > Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com> > > --- > > drivers/net/virtio/virtio_rxtx.c | 36 ++++++++++++++++++++---------------- > > 1 file changed, 20 insertions(+), 16 deletions(-) > > > > diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c > > index 2e7205b..b96d0cb 100644 > > --- a/drivers/net/virtio/virtio_rxtx.c > > +++ b/drivers/net/virtio/virtio_rxtx.c > > @@ -331,7 +331,7 @@ virtio_dev_rxtx_start(struct rte_eth_dev *dev) > > * - Allocate blank mbufs for the each rx descriptor > > * > > */ > > - int i; > > + int i, j; > > However, I don't quite like using "i, j, k" stuff. So, how about > renaming "j" to "ring_idx"? > > > PMD_INIT_FUNC_TRACE(); > > > > @@ -352,15 +352,18 @@ virtio_dev_rxtx_start(struct rte_eth_dev *dev) > > error = ENOSPC; > > > > #ifdef RTE_MACHINE_CPUFLAG_SSSE3 > > - if (use_simple_rxtx) > > - for (i = 0; i < vq->vq_nentries; i++) { > > - vq->vq_ring.avail->ring[i] = i; > > - vq->vq_ring.desc[i].flags = > VRING_DESC_F_WRITE; > > + if (use_simple_rxtx) { > > + uint16_t k; > > We could reuse "ring_idx" here; no need to define yet another iterate var > for that. Make sense. Besides, since comparison between unsigned and signed is a violation to static code analyzer, I'll redefine these variables as unsigned. Such as, int i -> uint16_t q_idx int j -> uint16_t r_idx k -> r_idx Thanks, Jianfeng > > --yliu ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [dpdk-dev] [PATCH] virito: fix reuse index in nested loop 2016-06-13 9:11 ` Tan, Jianfeng @ 2016-06-13 9:31 ` Yuanhan Liu 0 siblings, 0 replies; 4+ messages in thread From: Yuanhan Liu @ 2016-06-13 9:31 UTC (permalink / raw) To: Tan, Jianfeng; +Cc: dev, Xie, Huawei On Mon, Jun 13, 2016 at 09:11:57AM +0000, Tan, Jianfeng wrote: > > > > -----Original Message----- > > From: Yuanhan Liu [mailto:yuanhan.liu@linux.intel.com] > > Sent: Monday, June 13, 2016 4:58 PM > > To: Tan, Jianfeng > > Cc: dev@dpdk.org; Xie, Huawei > > Subject: Re: [PATCH] virito: fix reuse index in nested loop > > > > On Sun, Jun 12, 2016 at 10:05:45AM +0000, Jianfeng Tan wrote: > > > This patches fixes problem of reusing index of outmost loop in nested > > > loops. This bug will lead to failure when starting a multi queue > > > virtio device: rx queues (except from the first one) cannot be started, > > > expecially their vq_ring cannot be initialized, so that when invoking > > > rx func on these queues, segment fault happens. > > > > > > Fixes: a900472aedef ("virtio: split virtio Rx/Tx queue") > > > > Good catch! > > > > > Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com> > > > --- > > > drivers/net/virtio/virtio_rxtx.c | 36 ++++++++++++++++++++---------------- > > > 1 file changed, 20 insertions(+), 16 deletions(-) > > > > > > diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c > > > index 2e7205b..b96d0cb 100644 > > > --- a/drivers/net/virtio/virtio_rxtx.c > > > +++ b/drivers/net/virtio/virtio_rxtx.c > > > @@ -331,7 +331,7 @@ virtio_dev_rxtx_start(struct rte_eth_dev *dev) > > > * - Allocate blank mbufs for the each rx descriptor > > > * > > > */ > > > - int i; > > > + int i, j; > > > > However, I don't quite like using "i, j, k" stuff. So, how about > > renaming "j" to "ring_idx"? > > > > > PMD_INIT_FUNC_TRACE(); > > > > > > @@ -352,15 +352,18 @@ virtio_dev_rxtx_start(struct rte_eth_dev *dev) > > > error = ENOSPC; > > > > > > #ifdef RTE_MACHINE_CPUFLAG_SSSE3 > > > - if (use_simple_rxtx) > > > - for (i = 0; i < vq->vq_nentries; i++) { > > > - vq->vq_ring.avail->ring[i] = i; > > > - vq->vq_ring.desc[i].flags = > > VRING_DESC_F_WRITE; > > > + if (use_simple_rxtx) { > > > + uint16_t k; > > > > We could reuse "ring_idx" here; no need to define yet another iterate var > > for that. > > Make sense. Besides, since comparison between unsigned and signed is a violation to static code analyzer, I'll redefine these variables as unsigned. > Such as, > int i -> uint16_t q_idx > int j -> uint16_t r_idx > k -> r_idx It's nothing big deal, but if I were you, I would keep the var name "i" unchanged (yes, we need define it to uint16_t), and introduce "ring_idx" but not "r_idx": I will not sacrifice the readability by saving few typings. --yliu ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2016-06-13 9:29 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2016-06-12 10:05 [dpdk-dev] [PATCH] virito: fix reuse index in nested loop Jianfeng Tan 2016-06-13 8:57 ` Yuanhan Liu 2016-06-13 9:11 ` Tan, Jianfeng 2016-06-13 9:31 ` Yuanhan Liu
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