[dpdk-dev] 回复: [PATCH] net/mlx5: fix incorrect r/w lock usage in DMA unmap

[Feifei Wang <Feifei.Wang2@arm.com>]

Hi, Slava

That's OK. Thanks for your reviewing.

Best Regards
Feifei

> -----邮件原件-----
> 发件人: Slava Ovsiienko <viacheslavo@nvidia.com>
> 发送时间: 2021年7月1日 22:27
> 收件人: Feifei Wang <Feifei.Wang2@arm.com>; Matan Azrad
> <matan@nvidia.com>; Shahaf Shuler <shahafs@nvidia.com>
> 抄送: dev@dpdk.org; nd <nd@arm.com>; Shahaf Shuler
> <shahafs@nvidia.com>; stable@dpdk.org; Ruifeng Wang
> <Ruifeng.Wang@arm.com>; nd <nd@arm.com>
> 主题: RE: [PATCH] net/mlx5: fix incorrect r/w lock usage in DMA unmap
> 
> Hi, Feifei
> 
> Sorry for the delayed review.
> I think it is a good catch, thank you for the patch.
> 
> Acked-by: Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> 
> With best regards,
> Slava
> 
> > -----Original Message-----
> > From: Feifei Wang <Feifei.Wang2@arm.com>
> > Sent: Tuesday, June 22, 2021 4:54
> > To: Feifei Wang <Feifei.Wang2@arm.com>; Matan Azrad
> > <matan@nvidia.com>; Shahaf Shuler <shahafs@nvidia.com>; Slava
> > Ovsiienko <viacheslavo@nvidia.com>
> > Cc: dev@dpdk.org; nd <nd@arm.com>; Shahaf Shuler
> <shahafs@nvidia.com>;
> > stable@dpdk.org; Ruifeng Wang <Ruifeng.Wang@arm.com>; nd
> <nd@arm.com>
> > Subject: 回复: [PATCH] net/mlx5: fix incorrect r/w lock usage in DMA
> > unmap
> >
> > Hi, Slava
> >
> > Would you please help review this patch?
> > Thanks.
> >
> > Best Regards
> > Feifei
> >
> > > -----邮件原件-----
> > > 发件人: Feifei Wang <feifei.wang2@arm.com>
> > > 发送时间: 2021年5月27日 17:48
> > > 收件人: Matan Azrad <matan@nvidia.com>; Shahaf Shuler
> > > <shahafs@nvidia.com>; Viacheslav Ovsiienko <viacheslavo@nvidia.com>
> > > 抄送: dev@dpdk.org; nd <nd@arm.com>; Feifei Wang
> > <Feifei.Wang2@arm.com>;
> > > shahafs@mellanox.com; stable@dpdk.org; Ruifeng Wang
> > > <Ruifeng.Wang@arm.com>
> > > 主题: [PATCH] net/mlx5: fix incorrect r/w lock usage in DMA unmap
> > >
> > > For mlx5 DMA unmap, write lock should be used for rebuilding memory
> > > region cache table rather than read lock.
> > >
> > > Fixes: 989e999d9305 ("net/mlx5: support PCI device DMA map and
> > > unmap")
> > > Cc: shahafs@mellanox.com
> > > Cc: stable@dpdk.org
> > >
> > > Signed-off-by: Feifei Wang <feifei.wang2@arm.com>
> > > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
> > > ---
> > >  drivers/net/mlx5/mlx5_mr.c | 6 +++---
> > >  1 file changed, 3 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/net/mlx5/mlx5_mr.c b/drivers/net/mlx5/mlx5_mr.c
> > > index
> > > e791b6338d..45a122f4f9 100644
> > > --- a/drivers/net/mlx5/mlx5_mr.c
> > > +++ b/drivers/net/mlx5/mlx5_mr.c
> > > @@ -395,10 +395,10 @@ mlx5_dma_unmap(struct rte_pci_device *pdev,
> > void
> > > *addr,
> > >  	}
> > >  	priv = dev->data->dev_private;
> > >  	sh = priv->sh;
> > > -	rte_rwlock_read_lock(&sh->share_cache.rwlock);
> > > +	rte_rwlock_write_lock(&sh->share_cache.rwlock);
> > >  	mr = mlx5_mr_lookup_list(&sh->share_cache, &entry,
> > (uintptr_t)addr);
> > >  	if (!mr) {
> > > -		rte_rwlock_read_unlock(&sh->share_cache.rwlock);
> > > +		rte_rwlock_write_unlock(&sh->share_cache.rwlock);
> > >  		DRV_LOG(WARNING, "address 0x%" PRIxPTR " wasn't
> > registered "
> > >  				 "to PCI device %p", (uintptr_t)addr,
> > >  				 (void *)pdev);
> > > @@ -423,7 +423,7 @@ mlx5_dma_unmap(struct rte_pci_device *pdev,
> void
> > > *addr,
> > >  	DRV_LOG(DEBUG, "broadcasting local cache flush, gen=%d",
> > >  	      sh->share_cache.dev_gen);
> > >  	rte_smp_wmb();
> > > -	rte_rwlock_read_unlock(&sh->share_cache.rwlock);
> > > +	rte_rwlock_write_unlock(&sh->share_cache.rwlock);
> > >  	return 0;
> > >  }
> > >
> > > --
> > > 2.25.1