From: Tyrel Datwyler <tyreld@linux.ibm.com>
To: james.bottomley@hansenpartnership.com
Cc: Tyrel Datwyler <tyreld@linux.ibm.com>,
martin.petersen@oracle.com, linux-scsi@vger.kernel.org,
linux-kernel@vger.kernel.org, brking@linux.ibm.com,
linuxppc-dev@lists.ozlabs.org
Subject: [PATCH v3 18/18] ibmvfc: drop host lock when completing commands in CRQ
Date: Wed, 2 Dec 2020 20:08:06 -0600 [thread overview]
Message-ID: <20201203020806.14747-19-tyreld@linux.ibm.com> (raw)
In-Reply-To: <20201203020806.14747-1-tyreld@linux.ibm.com>
The legacy CRQ holds the host lock the even while completing commands.
This presents a problem when in legacy single queue mode and
nr_hw_queues is greater than one since calling scsi_done() introduces
the potential for deadlock.
If nr_hw_queues is greater than one drop the hostlock in the legacy CRQ
path when completing a command.
Signed-off-by: Tyrel Datwyler <tyreld@linux.ibm.com>
---
drivers/scsi/ibmvscsi/ibmvfc.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/ibmvscsi/ibmvfc.c b/drivers/scsi/ibmvscsi/ibmvfc.c
index e499599662ec..e2200bdff2be 100644
--- a/drivers/scsi/ibmvscsi/ibmvfc.c
+++ b/drivers/scsi/ibmvscsi/ibmvfc.c
@@ -2969,6 +2969,7 @@ static void ibmvfc_handle_crq(struct ibmvfc_crq *crq, struct ibmvfc_host *vhost)
{
long rc;
struct ibmvfc_event *evt = (struct ibmvfc_event *)be64_to_cpu(crq->ioba);
+ unsigned long flags;
switch (crq->valid) {
case IBMVFC_CRQ_INIT_RSP:
@@ -3039,7 +3040,12 @@ static void ibmvfc_handle_crq(struct ibmvfc_crq *crq, struct ibmvfc_host *vhost)
del_timer(&evt->timer);
list_del(&evt->queue);
ibmvfc_trc_end(evt);
- evt->done(evt);
+ if (nr_scsi_hw_queues > 1) {
+ spin_unlock_irqrestore(vhost->host->host_lock, flags);
+ evt->done(evt);
+ spin_lock_irqsave(vhost->host->host_lock, flags);
+ } else
+ evt->done(evt);
}
/**
--
2.27.0
next prev parent reply other threads:[~2020-12-03 2:41 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-03 2:07 [PATCH v3 00/18] ibmvfc: initial MQ development Tyrel Datwyler
2020-12-03 2:07 ` [PATCH v3 01/18] ibmvfc: add vhost fields and defaults for MQ enablement Tyrel Datwyler
2020-12-03 2:07 ` [PATCH v3 02/18] ibmvfc: define hcall wrapper for registering a Sub-CRQ Tyrel Datwyler
2020-12-03 2:07 ` [PATCH v3 03/18] ibmvfc: add Subordinate CRQ definitions Tyrel Datwyler
2020-12-03 2:07 ` [PATCH v3 04/18] ibmvfc: add alloc/dealloc routines for SCSI Sub-CRQ Channels Tyrel Datwyler
2020-12-04 14:47 ` Brian King
2020-12-05 0:15 ` Tyrel Datwyler
2020-12-03 2:07 ` [PATCH v3 05/18] ibmvfc: add Sub-CRQ IRQ enable/disable routine Tyrel Datwyler
2020-12-03 2:07 ` [PATCH v3 06/18] ibmvfc: add handlers to drain and complete Sub-CRQ responses Tyrel Datwyler
2020-12-04 14:51 ` Brian King
2020-12-05 0:16 ` Tyrel Datwyler
2020-12-03 2:07 ` [PATCH v3 07/18] ibmvfc: define Sub-CRQ interrupt handler routine Tyrel Datwyler
2020-12-03 2:07 ` [PATCH v3 08/18] ibmvfc: map/request irq and register Sub-CRQ interrupt handler Tyrel Datwyler
2020-12-03 2:07 ` [PATCH v3 09/18] ibmvfc: implement channel enquiry and setup commands Tyrel Datwyler
2020-12-03 2:07 ` [PATCH v3 10/18] ibmvfc: advertise client support for using hardware channels Tyrel Datwyler
2020-12-03 2:07 ` [PATCH v3 11/18] ibmvfc: set and track hw queue in ibmvfc_event struct Tyrel Datwyler
2020-12-03 2:08 ` [PATCH v3 12/18] ibmvfc: send commands down HW Sub-CRQ when channelized Tyrel Datwyler
2020-12-03 2:08 ` [PATCH v3 13/18] ibmvfc: register Sub-CRQ handles with VIOS during channel setup Tyrel Datwyler
2020-12-03 2:08 ` [PATCH v3 14/18] ibmvfc: add cancel mad initialization helper Tyrel Datwyler
2020-12-03 2:08 ` [PATCH v3 15/18] ibmvfc: send Cancel MAD down each hw scsi channel Tyrel Datwyler
2020-12-04 21:26 ` Brian King
2020-12-03 2:08 ` [PATCH v3 16/18] ibmvfc: enable MQ and set reasonable defaults Tyrel Datwyler
2020-12-03 2:08 ` [PATCH v3 17/18] ibmvfc: provide modules parameters for MQ settings Tyrel Datwyler
2020-12-04 21:28 ` Brian King
2020-12-03 2:08 ` Tyrel Datwyler [this message]
2020-12-04 21:35 ` [PATCH v3 18/18] ibmvfc: drop host lock when completing commands in CRQ Brian King
2020-12-05 0:20 ` Tyrel Datwyler
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