From: Mark Bloch <markb@mellanox.com>
To: Sagi Grimberg <sagi@grimberg.me>,
"linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Subject: Re: [PATCH v2] iwcm: don't hold the irq disabled lock on iw_rem_ref
Date: Wed, 4 Sep 2019 01:39:19 +0000 [thread overview]
Message-ID: <43be4b64-94f1-9ee7-93f9-4e683bdfe89a@mellanox.com> (raw)
In-Reply-To: <20190904011020.12845-1-sagi@grimberg.me>
On 9/3/2019 18:10, Sagi Grimberg wrote:
> This may be the final put on a qp and result in freeing
> resourcesand should not be done with interrupts disabled.
>
> Produce the following warning:
> --
> [ 317.026048] WARNING: CPU: 1 PID: 443 at kernel/smp.c:425 smp_call_function_many+0xa0/0x260
> [ 317.026131] Call Trace:
> [ 317.026159] ? load_new_mm_cr3+0xe0/0xe0
> [ 317.026161] on_each_cpu+0x28/0x50
> [ 317.026183] __purge_vmap_area_lazy+0x72/0x150
> [ 317.026200] free_vmap_area_noflush+0x7a/0x90
> [ 317.026202] remove_vm_area+0x6f/0x80
> [ 317.026203] __vunmap+0x71/0x210
> [ 317.026211] siw_free_qp+0x8d/0x130 [siw]
> [ 317.026217] destroy_cm_id+0xc3/0x200 [iw_cm]
> [ 317.026222] rdma_destroy_id+0x224/0x2b0 [rdma_cm]
> [ 317.026226] nvme_rdma_reset_ctrl_work+0x2c/0x70 [nvme_rdma]
> [ 317.026235] process_one_work+0x1f4/0x3e0
> [ 317.026249] worker_thread+0x221/0x3e0
> [ 317.026252] ? process_one_work+0x3e0/0x3e0
> [ 317.026256] kthread+0x117/0x130
> [ 317.026264] ? kthread_create_worker_on_cpu+0x70/0x70
> [ 317.026275] ret_from_fork+0x35/0x40
> --
>
> Signed-off-by: Sagi Grimberg <sagi@grimberg.me>
> ---
> changes from v1:
> - don't release the lock before qp pointer is cleared.
>
> drivers/infiniband/core/iwcm.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/infiniband/core/iwcm.c b/drivers/infiniband/core/iwcm.c
> index 72141c5b7c95..ad6fd5019285 100644
> --- a/drivers/infiniband/core/iwcm.c
> +++ b/drivers/infiniband/core/iwcm.c
> @@ -427,8 +427,10 @@ static void destroy_cm_id(struct iw_cm_id *cm_id)
> break;
> }
> if (cm_id_priv->qp) {
> - cm_id_priv->id.device->ops.iw_rem_ref(cm_id_priv->qp);
> cm_id_priv->qp = NULL;
> + spin_unlock_irqrestore(&cm_id_priv->lock, flags);
> + cm_id_priv->id.device->ops.iw_rem_ref(cm_id_priv->qp);
You are calling it with NULL now :)
I was thinking more about something like this:
diff --git a/drivers/infiniband/core/iwcm.c b/drivers/infiniband/core/iwcm.c
index 72141c5b7c95..c5d9a1ebace6 100644
--- a/drivers/infiniband/core/iwcm.c
+++ b/drivers/infiniband/core/iwcm.c
@@ -373,6 +373,7 @@ static void destroy_cm_id(struct iw_cm_id *cm_id)
{
struct iwcm_id_private *cm_id_priv;
unsigned long flags;
+ struct ib_qp *qp;
cm_id_priv = container_of(cm_id, struct iwcm_id_private, id);
/*
@@ -426,12 +427,14 @@ static void destroy_cm_id(struct iw_cm_id *cm_id)
BUG();
break;
}
- if (cm_id_priv->qp) {
- cm_id_priv->id.device->ops.iw_rem_ref(cm_id_priv->qp);
- cm_id_priv->qp = NULL;
- }
+
+ qp = cm_id_priv->qp;
+ cm_id_priv->qp = NULL;
spin_unlock_irqrestore(&cm_id_priv->lock, flags);
+ if (qp)
+ cm_id_priv->id.device->ops.iw_rem_ref(qp);
+
if (cm_id->mapped) {
iwpm_remove_mapinfo(&cm_id->local_addr, &cm_id->m_local_addr);
iwpm_remove_mapping(&cm_id->local_addr, RDMA_NL_IWCM);
> + spin_lock_irqsave(&cm_id_priv->lock, flags);
> }
> spin_unlock_irqrestore(&cm_id_priv->lock, flags);
>
>
prev parent reply other threads:[~2019-09-04 1:39 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-09-04 1:10 [PATCH v2] iwcm: don't hold the irq disabled lock on iw_rem_ref Sagi Grimberg
2019-09-04 1:39 ` Mark Bloch [this message]
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