scsi: qedf: make qedf_execute_tmf non-preemptible

[PATCH] scsi: qedf: make qedf_execute_tmf non-preemptible

Posted by John Meneghini 1 year, 10 months ago

Stop calling smp_processor_id from preemptible code in qedf_execute_tmf.
This results in BUGON when running an RT kernel.

[ 659.343280] BUG: using smp_processor_id() in preemptible [00000000] code: sg_reset/3646
[ 659.343282] caller is qedf_execute_tmf+0x8b/0x360 [qedf]

Tested-by: Guangwu Zhang <guazhang@redhat.com>
Cc: Saurav Kashyap <skashyap@marvell.com>
Cc: Nilesh Javali <njavali@marvell.com>
Signed-off-by: John Meneghini <jmeneghi@redhat.com>
---
 drivers/scsi/qedf/qedf_io.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/qedf/qedf_io.c b/drivers/scsi/qedf/qedf_io.c
index bf921caaf6ae..054a51713d55 100644
--- a/drivers/scsi/qedf/qedf_io.c
+++ b/drivers/scsi/qedf/qedf_io.c
@@ -2324,9 +2324,6 @@ static int qedf_execute_tmf(struct qedf_rport *fcport, u64 tm_lun,
 	io_req->fcport = fcport;
 	io_req->cmd_type = QEDF_TASK_MGMT_CMD;
 
-	/* Record which cpu this request is associated with */
-	io_req->cpu = smp_processor_id();
-
 	/* Set TM flags */
 	io_req->io_req_flags = QEDF_READ;
 	io_req->data_xfer_len = 0;
@@ -2349,6 +2346,9 @@ static int qedf_execute_tmf(struct qedf_rport *fcport, u64 tm_lun,
 
 	spin_lock_irqsave(&fcport->rport_lock, flags);
 
+	/* Record which cpu this request is associated with */
+	io_req->cpu = smp_processor_id();
+
 	sqe_idx = qedf_get_sqe_idx(fcport);
 	sqe = &fcport->sq[sqe_idx];
 	memset(sqe, 0, sizeof(struct fcoe_wqe));
-- 
2.39.3

Re: [PATCH] scsi: qedf: make qedf_execute_tmf non-preemptible

Posted by Martin K. Petersen 1 year, 9 months ago

On Wed, 03 Apr 2024 11:01:55 -0400, John Meneghini wrote:

> Stop calling smp_processor_id from preemptible code in qedf_execute_tmf.
> This results in BUGON when running an RT kernel.
> 
> [ 659.343280] BUG: using smp_processor_id() in preemptible [00000000] code: sg_reset/3646
> [ 659.343282] caller is qedf_execute_tmf+0x8b/0x360 [qedf]
> 
> 
> [...]

Applied to 6.10/scsi-queue, thanks!

[1/1] scsi: qedf: make qedf_execute_tmf non-preemptible
      https://git.kernel.org/mkp/scsi/c/0d8b637c9c5e

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH] scsi: qedf: make qedf_execute_tmf non-preemptible

Posted by Martin K. Petersen 1 year, 9 months ago

John,

> Stop calling smp_processor_id from preemptible code in
> qedf_execute_tmf. This results in BUGON when running an RT kernel.

Applied to 6.10/scsi-staging, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering