Re: [PATCH v3 20/77] ncr5380: Introduce unbound workqueue
From: Hannes Reinecke
Date: Tue Dec 22 2015 - 02:10:52 EST
On 12/22/2015 02:17 AM, Finn Thain wrote:
Allocate a work queue that will permit busy waiting and sleeping. This
means NCR5380_init() can potentially fail, so add this error path.
Signed-off-by: Finn Thain <fthain@xxxxxxxxxxxxxxxxxxx>
---
In subsequent patches, the work function adopts this work queue so it
can sleep while polling, which allows the removal of some flawed and
complicated code in NCR5380_select() in NCR5380.c.
Changed since v1:
- Dropped WQ_CPU_INTENSIVE flag because Documentation/workqueue.txt says it
"is meaningless for unbound wq".
---
drivers/scsi/NCR5380.c | 15 +++++++++++----
drivers/scsi/NCR5380.h | 1 +
drivers/scsi/arm/cumana_1.c | 8 ++++++--
drivers/scsi/arm/oak.c | 8 ++++++--
drivers/scsi/atari_NCR5380.c | 8 +++++++-
drivers/scsi/atari_scsi.c | 5 ++++-
drivers/scsi/dmx3191d.c | 17 +++++++++++------
drivers/scsi/dtc.c | 11 +++++++++--
drivers/scsi/g_NCR5380.c | 31 +++++++++++++++----------------
drivers/scsi/mac_scsi.c | 5 ++++-
drivers/scsi/pas16.c | 10 ++++++++--
drivers/scsi/sun3_scsi.c | 5 ++++-
drivers/scsi/t128.c | 13 ++++++++++---
13 files changed, 96 insertions(+), 41 deletions(-)
Index: linux/drivers/scsi/NCR5380.c
===================================================================
--- linux.orig/drivers/scsi/NCR5380.c 2015-12-22 12:15:52.000000000 +1100
+++ linux/drivers/scsi/NCR5380.c 2015-12-22 12:15:56.000000000 +1100
@@ -514,7 +514,7 @@ static int should_disconnect(unsigned ch
static void NCR5380_set_timer(struct NCR5380_hostdata *hostdata, unsigned long timeout)
{
hostdata->time_expires = jiffies + timeout;
- schedule_delayed_work(&hostdata->coroutine, timeout);
+ queue_delayed_work(hostdata->work_q, &hostdata->coroutine, timeout);
}
@@ -791,7 +791,12 @@ static int NCR5380_init(struct Scsi_Host
hostdata->disconnected_queue = NULL;
INIT_DELAYED_WORK(&hostdata->coroutine, NCR5380_main);
-
+ hostdata->work_q = alloc_workqueue("ncr5380_%d",
+ WQ_UNBOUND | WQ_MEM_RECLAIM,
+ 1, instance->host_no);
+ if (!hostdata->work_q)
+ return -ENOMEM;
+
/* The CHECK code seems to break the 53C400. Will check it later maybe */
if (flags & FLAG_NCR53C400)
hostdata->flags = FLAG_HAS_LAST_BYTE_SENT | flags;
Wouldn't it be better to use a normal (ie bound) workqueue here?
SCSI-2 is pretty much single-threaded, so shifting things onto arbitrary
CPUs don't sound very appealing.
Cheers,
Hannes
--
Dr. Hannes Reinecke zSeries & Storage
hare@xxxxxxx +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/