* [PATCH 8/9] rsxx: Fixes CPU usage issues on RHEL 6 Kernels.
@ 2013-04-30 20:00 Philip J. Kelleher
2013-05-01 11:44 ` Jens Axboe
0 siblings, 1 reply; 4+ messages in thread
From: Philip J. Kelleher @ 2013-04-30 20:00 UTC (permalink / raw)
To: axboe; +Cc: linux-kernel, klebers, brking
From: Philip J Kelleher <pjk1939@linux.vnet.ibm.com>
This changes how the driver schedules the work to the
workqueue threads.
Note: This patch is primarily for the Red Hat 6 Kernels.
Signed-off-by: Philip J Kelleher <pjk1939@linux.vnet.ibm.com>
-------------------------------------------------------------------------------
diff -uprN -X linux-block-vanilla/Documentation/dontdiff linux-block-vanilla/drivers/block/rsxx/dma.c linux-block/drivers/block/rsxx/dma.c
--- linux-block-vanilla/drivers/block/rsxx/dma.c 2013-04-29 17:03:44.471622413 -0500
+++ linux-block/drivers/block/rsxx/dma.c 2013-04-29 17:06:33.876241301 -0500
@@ -382,15 +382,13 @@ static void dma_engine_stalled(unsigned
}
}
-static void rsxx_issue_dmas(struct work_struct *work)
+static void rsxx_issue_dmas(struct rsxx_dma_ctrl *ctrl)
{
- struct rsxx_dma_ctrl *ctrl;
struct rsxx_dma *dma;
int tag;
int cmds_pending = 0;
struct hw_cmd *hw_cmd_buf;
- ctrl = container_of(work, struct rsxx_dma_ctrl, issue_dma_work);
hw_cmd_buf = ctrl->cmd.buf;
if (unlikely(ctrl->card->halt) ||
@@ -470,9 +468,8 @@ static void rsxx_issue_dmas(struct work_
}
}
-static void rsxx_dma_done(struct work_struct *work)
+static void rsxx_dma_done(struct rsxx_dma_ctrl *ctrl)
{
- struct rsxx_dma_ctrl *ctrl;
struct rsxx_dma *dma;
unsigned long flags;
u16 count;
@@ -480,7 +477,6 @@ static void rsxx_dma_done(struct work_st
u8 tag;
struct hw_status *hw_st_buf;
- ctrl = container_of(work, struct rsxx_dma_ctrl, dma_done_work);
hw_st_buf = ctrl->status.buf;
if (unlikely(ctrl->card->halt) ||
@@ -556,6 +552,28 @@ static void rsxx_dma_done(struct work_st
spin_unlock_bh(&ctrl->queue_lock);
}
+static void rsxx_schedule_issue(struct work_struct *work)
+{
+ struct rsxx_dma_ctrl *ctrl;
+
+ ctrl = container_of(work, struct rsxx_dma_ctrl, issue_dma_work);
+
+ mutex_lock(&ctrl->work_lock);
+ rsxx_issue_dmas(ctrl);
+ mutex_unlock(&ctrl->work_lock);
+}
+
+static void rsxx_schedule_done(struct work_struct *work)
+{
+ struct rsxx_dma_ctrl *ctrl;
+
+ ctrl = container_of(work, struct rsxx_dma_ctrl, dma_done_work);
+
+ mutex_lock(&ctrl->work_lock);
+ rsxx_dma_done(ctrl);
+ mutex_unlock(&ctrl->work_lock);
+}
+
static int rsxx_queue_discard(struct rsxx_cardinfo *card,
struct list_head *q,
unsigned int laddr,
@@ -799,6 +817,7 @@ static int rsxx_dma_ctrl_init(struct pci
spin_lock_init(&ctrl->trackers->lock);
spin_lock_init(&ctrl->queue_lock);
+ mutex_init(&ctrl->work_lock);
INIT_LIST_HEAD(&ctrl->queue);
setup_timer(&ctrl->activity_timer, dma_engine_stalled,
@@ -812,8 +831,8 @@ static int rsxx_dma_ctrl_init(struct pci
if (!ctrl->done_wq)
return -ENOMEM;
- INIT_WORK(&ctrl->issue_dma_work, rsxx_issue_dmas);
- INIT_WORK(&ctrl->dma_done_work, rsxx_dma_done);
+ INIT_WORK(&ctrl->issue_dma_work, rsxx_schedule_issue);
+ INIT_WORK(&ctrl->dma_done_work, rsxx_schedule_done);
st = rsxx_hw_buffers_init(dev, ctrl);
if (st)
diff -uprN -X linux-block-vanilla/Documentation/dontdiff linux-block-vanilla/drivers/block/rsxx/rsxx_priv.h linux-block/drivers/block/rsxx/rsxx_priv.h
--- linux-block-vanilla/drivers/block/rsxx/rsxx_priv.h 2013-04-29 17:03:44.477354090 -0500
+++ linux-block/drivers/block/rsxx/rsxx_priv.h 2013-04-29 17:06:33.884248200 -0500
@@ -115,6 +115,7 @@ struct rsxx_dma_ctrl {
struct timer_list activity_timer;
struct dma_tracker_list *trackers;
struct rsxx_dma_stats stats;
+ struct mutex work_lock;
};
struct rsxx_cardinfo {
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 8/9] rsxx: Fixes CPU usage issues on RHEL 6 Kernels.
2013-04-30 20:00 [PATCH 8/9] rsxx: Fixes CPU usage issues on RHEL 6 Kernels Philip J. Kelleher
@ 2013-05-01 11:44 ` Jens Axboe
2013-05-01 14:34 ` Philip J. Kelleher
0 siblings, 1 reply; 4+ messages in thread
From: Jens Axboe @ 2013-05-01 11:44 UTC (permalink / raw)
To: Philip J. Kelleher; +Cc: linux-kernel, klebers, brking
On Tue, Apr 30 2013, Philip J. Kelleher wrote:
> From: Philip J Kelleher <pjk1939@linux.vnet.ibm.com>
>
> This changes how the driver schedules the work to the
> workqueue threads.
>
> Note: This patch is primarily for the Red Hat 6 Kernels.
You need to properly explain the problem and how it's fixed in the
changelog. The above really makes the read none the wiser on what the
issue is.
--
Jens Axboe
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 8/9] rsxx: Fixes CPU usage issues on RHEL 6 Kernels.
2013-05-01 11:44 ` Jens Axboe
@ 2013-05-01 14:34 ` Philip J. Kelleher
2013-05-01 19:35 ` Jens Axboe
0 siblings, 1 reply; 4+ messages in thread
From: Philip J. Kelleher @ 2013-05-01 14:34 UTC (permalink / raw)
To: Jens Axboe; +Cc: linux-kernel, klebers, brking
Again, thanks for the prompt reply.
Also, sorry for my poor explaination skills :)
The RHEL 6.x version of the driver is using the legacy
worqueue create function, 'create_singlethread_workqueue'.
This would cause heavy usage of one CPU if data was being
thrashed pretty hard. So, in order to fix it, workqueues
are now being created with 'create_workqueue' and
synchronization with mutexes.
Thanks,
-Philip Kelleher
On Wed, May 01, 2013 at 01:44:20PM +0200, Jens Axboe wrote:
> On Tue, Apr 30 2013, Philip J. Kelleher wrote:
> > From: Philip J Kelleher <pjk1939@linux.vnet.ibm.com>
> >
> > This changes how the driver schedules the work to the
> > workqueue threads.
> >
> > Note: This patch is primarily for the Red Hat 6 Kernels.
>
> You need to properly explain the problem and how it's fixed in the
> changelog. The above really makes the read none the wiser on what the
> issue is.
>
> --
> Jens Axboe
>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 8/9] rsxx: Fixes CPU usage issues on RHEL 6 Kernels.
2013-05-01 14:34 ` Philip J. Kelleher
@ 2013-05-01 19:35 ` Jens Axboe
0 siblings, 0 replies; 4+ messages in thread
From: Jens Axboe @ 2013-05-01 19:35 UTC (permalink / raw)
To: Philip J. Kelleher; +Cc: linux-kernel, klebers, brking
On Wed, May 01 2013, Philip J. Kelleher wrote:
> Again, thanks for the prompt reply.
>
> Also, sorry for my poor explaination skills :)
>
> The RHEL 6.x version of the driver is using the legacy
> worqueue create function, 'create_singlethread_workqueue'.
> This would cause heavy usage of one CPU if data was being
> thrashed pretty hard. So, in order to fix it, workqueues
> are now being created with 'create_workqueue' and
> synchronization with mutexes.
See, that is what should have been in the changelog!
--
Jens Axboe
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2013-05-01 19:35 UTC | newest]
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2013-04-30 20:00 [PATCH 8/9] rsxx: Fixes CPU usage issues on RHEL 6 Kernels Philip J. Kelleher
2013-05-01 11:44 ` Jens Axboe
2013-05-01 14:34 ` Philip J. Kelleher
2013-05-01 19:35 ` Jens Axboe
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