From: Jason Gunthorpe <jgg@nvidia.com>
To: "Marciniszyn, Mike" <mike.marciniszyn@cornelisnetworks.com>
Cc: Weihang Li <liweihang@huawei.com>,
"dledford@redhat.com" <dledford@redhat.com>,
"leon@kernel.org" <leon@kernel.org>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>,
"linuxarm@huawei.com" <linuxarm@huawei.com>,
"Dalessandro, Dennis" <dennis.dalessandro@cornelisnetworks.com>
Subject: Re: [PATCH v3 for-next 13/13] RDMA/rdmavt: Use refcount_t instead of atomic_t on refcount of rvt_mcast
Date: Thu, 27 May 2021 10:15:58 -0300 [thread overview]
Message-ID: <20210527131558.GB1002214@nvidia.com> (raw)
In-Reply-To: <CH0PR01MB715336ACBA211A001E362E6BF2239@CH0PR01MB7153.prod.exchangelabs.com>
On Thu, May 27, 2021 at 01:08:37PM +0000, Marciniszyn, Mike wrote:
> > +++ b/drivers/infiniband/hw/hfi1/verbs.c
> > @@ -534,7 +534,8 @@ static inline void hfi1_handle_packet(struct
> > hfi1_packet *packet,
> > * Notify rvt_multicast_detach() if it is waiting for us
> > * to finish.
> > */
> > - if (atomic_dec_return(&mcast->refcount) <= 1)
> > + refcount_dec(&mcast->refcount);
> > + if (refcount_read(&mcast->refcount) <= 1)
> > wake_up(&mcast->wait);
>
> Is there refcount_ that preserves the atomic characteristics of the single call?
You are supposed to us refcount_dec_and_test() for patterns like this,
this hunk looks wrong to me
Jason
next prev parent reply other threads:[~2021-05-27 13:16 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-25 6:51 [PATCH v3 for-next 00/13] RDMA: Use refcount_t for reference counting Weihang Li
2021-05-25 6:51 ` [PATCH v3 for-next 01/13] RDMA/core: Use refcount_t instead of atomic_t on refcount of iwcm_id_private Weihang Li
2021-05-25 6:51 ` [PATCH v3 for-next 02/13] RDMA/core: Use refcount_t instead of atomic_t on refcount of iwpm_admin_data Weihang Li
2021-05-25 6:51 ` [PATCH v3 for-next 03/13] RDMA/core: Use refcount_t instead of atomic_t on refcount of ib_mad_snoop_private Weihang Li
2021-05-25 6:51 ` [PATCH v3 for-next 04/13] RDMA/core: Use refcount_t instead of atomic_t on refcount of mcast_member Weihang Li
2021-05-25 6:51 ` [PATCH v3 for-next 05/13] RDMA/core: Use refcount_t instead of atomic_t on refcount of mcast_port Weihang Li
2021-05-25 6:51 ` [PATCH v3 for-next 06/13] RDMA/core: Use refcount_t instead of atomic_t on refcount of mcast_group Weihang Li
2021-05-25 6:51 ` [PATCH v3 for-next 07/13] RDMA/core: Use refcount_t instead of atomic_t on refcount of ib_uverbs_device Weihang Li
2021-05-25 6:51 ` [PATCH v3 for-next 08/13] RDMA/hns: Use refcount_t instead of atomic_t for CQ reference counting Weihang Li
2021-05-25 6:51 ` [PATCH v3 for-next 09/13] RDMA/hns: Use refcount_t instead of atomic_t for SRQ " Weihang Li
2021-05-25 6:51 ` [PATCH v3 for-next 10/13] RDMA/hns: Use refcount_t instead of atomic_t for QP " Weihang Li
2021-05-25 6:51 ` [PATCH v3 for-next 11/13] RDMA/cxgb4: Use refcount_t instead of atomic_t for " Weihang Li
2021-05-25 6:51 ` [PATCH v3 for-next 12/13] RDMA/ipoib: " Weihang Li
2021-05-25 6:51 ` [PATCH v3 for-next 13/13] RDMA/rdmavt: Use refcount_t instead of atomic_t on refcount of rvt_mcast Weihang Li
2021-05-27 13:08 ` Marciniszyn, Mike
2021-05-27 13:15 ` Jason Gunthorpe [this message]
2021-05-28 3:58 ` liweihang
2021-05-28 7:01 ` Peter Zijlstra
2021-05-28 8:22 ` liweihang
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