* [PATCH] wifi: mwifiex: Replace RX workqueues with kthreads
@ 2023-06-09 10:35 Pin-yen Lin
2023-06-09 10:41 ` Kalle Valo
0 siblings, 1 reply; 5+ messages in thread
From: Pin-yen Lin @ 2023-06-09 10:35 UTC (permalink / raw)
To: Amitkumar Karwar, Ganapathi Bhat, Sharvari Harisangam, Xinming Hu,
Kalle Valo
Cc: Brian Norris, linux-wireless, linux-kernel, Pin-yen Lin
This improves the RX throughput likely by better locality for the work
loads.
We tested this patch on Mediatek MT8173 Chromebooks, and it shows ~80%
Rx throughput improvement on high data rate test cases.
Signed-off-by: Pin-yen Lin <treapking@chromium.org>
---
.../wireless/marvell/mwifiex/11n_rxreorder.c | 2 +-
.../net/wireless/marvell/mwifiex/cfg80211.c | 2 +-
drivers/net/wireless/marvell/mwifiex/main.c | 29 ++++++++-----------
drivers/net/wireless/marvell/mwifiex/main.h | 5 ++--
4 files changed, 17 insertions(+), 21 deletions(-)
diff --git a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
index 391793a16adc..431f6dc61f5b 100644
--- a/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
+++ b/drivers/net/wireless/marvell/mwifiex/11n_rxreorder.c
@@ -198,7 +198,7 @@ mwifiex_del_rx_reorder_entry(struct mwifiex_private *priv,
priv->adapter->rx_locked = true;
if (priv->adapter->rx_processing) {
spin_unlock_bh(&priv->adapter->rx_proc_lock);
- flush_workqueue(priv->adapter->rx_workqueue);
+ kthread_flush_worker(priv->adapter->rx_thread);
} else {
spin_unlock_bh(&priv->adapter->rx_proc_lock);
}
diff --git a/drivers/net/wireless/marvell/mwifiex/cfg80211.c b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
index bcd564dc3554..f985bff4e52c 100644
--- a/drivers/net/wireless/marvell/mwifiex/cfg80211.c
+++ b/drivers/net/wireless/marvell/mwifiex/cfg80211.c
@@ -872,7 +872,7 @@ static int mwifiex_deinit_priv_params(struct mwifiex_private *priv)
adapter->rx_locked = true;
if (adapter->rx_processing) {
spin_unlock_bh(&adapter->rx_proc_lock);
- flush_workqueue(adapter->rx_workqueue);
+ kthread_flush_worker(adapter->rx_thread);
} else {
spin_unlock_bh(&adapter->rx_proc_lock);
}
diff --git a/drivers/net/wireless/marvell/mwifiex/main.c b/drivers/net/wireless/marvell/mwifiex/main.c
index ea22a08e6c08..bab963f3db83 100644
--- a/drivers/net/wireless/marvell/mwifiex/main.c
+++ b/drivers/net/wireless/marvell/mwifiex/main.c
@@ -168,7 +168,7 @@ static void mwifiex_queue_rx_work(struct mwifiex_adapter *adapter)
spin_unlock_bh(&adapter->rx_proc_lock);
} else {
spin_unlock_bh(&adapter->rx_proc_lock);
- queue_work(adapter->rx_workqueue, &adapter->rx_work);
+ kthread_queue_work(adapter->rx_thread, &adapter->rx_work);
}
}
@@ -526,9 +526,10 @@ static void mwifiex_terminate_workqueue(struct mwifiex_adapter *adapter)
adapter->workqueue = NULL;
}
- if (adapter->rx_workqueue) {
- destroy_workqueue(adapter->rx_workqueue);
- adapter->rx_workqueue = NULL;
+ if (adapter->rx_thread) {
+ kthread_flush_worker(adapter->rx_thread);
+ kthread_destroy_worker(adapter->rx_thread);
+ adapter->rx_thread = NULL;
}
}
@@ -1394,7 +1395,7 @@ int is_command_pending(struct mwifiex_adapter *adapter)
*
* It handles the RX operations.
*/
-static void mwifiex_rx_work_queue(struct work_struct *work)
+static void mwifiex_rx_work_queue(struct kthread_work *work)
{
struct mwifiex_adapter *adapter =
container_of(work, struct mwifiex_adapter, rx_work);
@@ -1554,13 +1555,10 @@ mwifiex_reinit_sw(struct mwifiex_adapter *adapter)
INIT_WORK(&adapter->main_work, mwifiex_main_work_queue);
if (adapter->rx_work_enabled) {
- adapter->rx_workqueue = alloc_workqueue("MWIFIEX_RX_WORK_QUEUE",
- WQ_HIGHPRI |
- WQ_MEM_RECLAIM |
- WQ_UNBOUND, 1);
- if (!adapter->rx_workqueue)
+ adapter->rx_thread = kthread_create_worker(0, "MWIFIEX_RX");
+ if (IS_ERR(adapter->rx_thread))
goto err_kmalloc;
- INIT_WORK(&adapter->rx_work, mwifiex_rx_work_queue);
+ kthread_init_work(&adapter->rx_work, mwifiex_rx_work_queue);
}
/* Register the device. Fill up the private data structure with
@@ -1709,14 +1707,11 @@ mwifiex_add_card(void *card, struct completion *fw_done,
INIT_WORK(&adapter->main_work, mwifiex_main_work_queue);
if (adapter->rx_work_enabled) {
- adapter->rx_workqueue = alloc_workqueue("MWIFIEX_RX_WORK_QUEUE",
- WQ_HIGHPRI |
- WQ_MEM_RECLAIM |
- WQ_UNBOUND, 1);
- if (!adapter->rx_workqueue)
+ adapter->rx_thread = kthread_create_worker(0, "MWIFIEX_RX");
+ if (!adapter->rx_thread)
goto err_kmalloc;
- INIT_WORK(&adapter->rx_work, mwifiex_rx_work_queue);
+ kthread_init_work(&adapter->rx_work, mwifiex_rx_work_queue);
}
/* Register the device. Fill up the private data structure with relevant
diff --git a/drivers/net/wireless/marvell/mwifiex/main.h b/drivers/net/wireless/marvell/mwifiex/main.h
index b95886e1413e..3255f9a5c2d4 100644
--- a/drivers/net/wireless/marvell/mwifiex/main.h
+++ b/drivers/net/wireless/marvell/mwifiex/main.h
@@ -32,6 +32,7 @@
#include <linux/gfp.h>
#include <linux/interrupt.h>
#include <linux/io.h>
+#include <linux/kthread.h>
#include <linux/of_gpio.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
@@ -886,8 +887,8 @@ struct mwifiex_adapter {
atomic_t tx_hw_pending;
struct workqueue_struct *workqueue;
struct work_struct main_work;
- struct workqueue_struct *rx_workqueue;
- struct work_struct rx_work;
+ struct kthread_worker *rx_thread;
+ struct kthread_work rx_work;
struct workqueue_struct *dfs_workqueue;
struct work_struct dfs_work;
bool rx_work_enabled;
--
2.41.0.162.gfafddb0af9-goog
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH] wifi: mwifiex: Replace RX workqueues with kthreads
2023-06-09 10:35 [PATCH] wifi: mwifiex: Replace RX workqueues with kthreads Pin-yen Lin
@ 2023-06-09 10:41 ` Kalle Valo
2023-06-09 17:41 ` Pin-yen Lin
0 siblings, 1 reply; 5+ messages in thread
From: Kalle Valo @ 2023-06-09 10:41 UTC (permalink / raw)
To: Pin-yen Lin
Cc: Amitkumar Karwar, Ganapathi Bhat, Sharvari Harisangam, Xinming Hu,
Brian Norris, linux-wireless, linux-kernel
Pin-yen Lin <treapking@chromium.org> writes:
> This improves the RX throughput likely by better locality for the work
> loads.
>
> We tested this patch on Mediatek MT8173 Chromebooks, and it shows ~80%
> Rx throughput improvement on high data rate test cases.
80%? That's huge from so small patch like this! What are the before and
after numbers?
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] wifi: mwifiex: Replace RX workqueues with kthreads
2023-06-09 10:41 ` Kalle Valo
@ 2023-06-09 17:41 ` Pin-yen Lin
2023-06-12 23:47 ` Brian Norris
0 siblings, 1 reply; 5+ messages in thread
From: Pin-yen Lin @ 2023-06-09 17:41 UTC (permalink / raw)
To: Kalle Valo
Cc: Amitkumar Karwar, Ganapathi Bhat, Sharvari Harisangam, Xinming Hu,
Brian Norris, linux-wireless, linux-kernel
Hi Kalle,
On Fri, Jun 9, 2023 at 6:41 PM Kalle Valo <kvalo@kernel.org> wrote:
>
> Pin-yen Lin <treapking@chromium.org> writes:
>
> > This improves the RX throughput likely by better locality for the work
> > loads.
> >
> > We tested this patch on Mediatek MT8173 Chromebooks, and it shows ~80%
> > Rx throughput improvement on high data rate test cases.
>
> 80%? That's huge from so small patch like this! What are the before and
> after numbers?
I realized that I might have over-simplified the background and the
impact of this patch...
The short answer to the question is that the throughput improved from
100 mbps to 180 mbps. The test was run on ChromeOS's v5.15 kernel
fork. More detailed test setting is mentioned in [1].
However, the throughput of the same test case on our v4.19 kernel is
320 mbps. That is, we observed a 320 mbps --> 100 mbps regression when
we tried to update the kernel version. This patch is more like a
mitigation of the regression. It improves the throughput, even though
it is still not as good as the older kernel.
That being said, this patch does improve the throughput, so we think
this patch can be landed into the mainline kernel.
Best regards,
Pin-yen
[1]: https://lore.kernel.org/all/ZFvpJb9Dh0FCkLQA@google.com/
>
> --
> https://patchwork.kernel.org/project/linux-wireless/list/
>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] wifi: mwifiex: Replace RX workqueues with kthreads
2023-06-09 17:41 ` Pin-yen Lin
@ 2023-06-12 23:47 ` Brian Norris
2023-06-13 5:12 ` Kalle Valo
0 siblings, 1 reply; 5+ messages in thread
From: Brian Norris @ 2023-06-12 23:47 UTC (permalink / raw)
To: Pin-yen Lin
Cc: Kalle Valo, Amitkumar Karwar, Ganapathi Bhat, Sharvari Harisangam,
Xinming Hu, linux-wireless, linux-kernel
Hi,
Thanks Pin-yen for most of the investigation here and for pushing the
patch. With some additional information though, I might suggest *not*
landing this patch at the moment. More details appended:
On Sat, Jun 10, 2023 at 01:41:51AM +0800, Pin-yen Lin wrote:
> I realized that I might have over-simplified the background and the
> impact of this patch...
>
> The short answer to the question is that the throughput improved from
> 100 mbps to 180 mbps. The test was run on ChromeOS's v5.15 kernel
> fork. More detailed test setting is mentioned in [1].
>
> However, the throughput of the same test case on our v4.19 kernel is
> 320 mbps. That is, we observed a 320 mbps --> 100 mbps regression when
> we tried to update the kernel version. This patch is more like a
> mitigation of the regression. It improves the throughput, even though
> it is still not as good as the older kernel.
>
> That being said, this patch does improve the throughput, so we think
> this patch can be landed into the mainline kernel.
>
> Best regards,
> Pin-yen
>
> [1]: https://lore.kernel.org/all/ZFvpJb9Dh0FCkLQA@google.com/
I (we?) was optimistic this would be an improvement (or at least, no
worse) due to some of the reasoning at [1]. And, the work here is just a
single work item, queued repeatedly to the same unbound workqueue. So
conceptually, it shouldn't be much different than a kthread_worker,
except for scheduler details -- where again, we'd think this should be
an improvement, as the scheduler would now better track load for the
task (mwifiex RX) in question.
But additional testing on other mwifiex-based systems (RK3399 + PCIE
8997) showed the inverse: some throughput drops on similar benchmarks,
from 110 Mbps to 80 Mbps. (Frankly, both numbers are significantly below
where we might like...)
Considering we still don't have a full explanation for all the
performance differences we've been seeing (on either test platform), and
that at least one of our platforms showed a (smaller) regression, I
think we might want to do more research before committing to this.
Brian
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] wifi: mwifiex: Replace RX workqueues with kthreads
2023-06-12 23:47 ` Brian Norris
@ 2023-06-13 5:12 ` Kalle Valo
0 siblings, 0 replies; 5+ messages in thread
From: Kalle Valo @ 2023-06-13 5:12 UTC (permalink / raw)
To: Brian Norris
Cc: Pin-yen Lin, Amitkumar Karwar, Ganapathi Bhat,
Sharvari Harisangam, Xinming Hu, linux-wireless, linux-kernel
Brian Norris <briannorris@chromium.org> writes:
> Hi,
>
> Thanks Pin-yen for most of the investigation here and for pushing the
> patch. With some additional information though, I might suggest *not*
> landing this patch at the moment. More details appended:
>
> On Sat, Jun 10, 2023 at 01:41:51AM +0800, Pin-yen Lin wrote:
>> I realized that I might have over-simplified the background and the
>> impact of this patch...
>>
>> The short answer to the question is that the throughput improved from
>> 100 mbps to 180 mbps. The test was run on ChromeOS's v5.15 kernel
>> fork. More detailed test setting is mentioned in [1].
>>
>> However, the throughput of the same test case on our v4.19 kernel is
>> 320 mbps. That is, we observed a 320 mbps --> 100 mbps regression when
>> we tried to update the kernel version. This patch is more like a
>> mitigation of the regression. It improves the throughput, even though
>> it is still not as good as the older kernel.
>>
>> That being said, this patch does improve the throughput, so we think
>> this patch can be landed into the mainline kernel.
>>
>> Best regards,
>> Pin-yen
>>
>> [1]: https://lore.kernel.org/all/ZFvpJb9Dh0FCkLQA@google.com/
>
> I (we?) was optimistic this would be an improvement (or at least, no
> worse) due to some of the reasoning at [1]. And, the work here is just a
> single work item, queued repeatedly to the same unbound workqueue. So
> conceptually, it shouldn't be much different than a kthread_worker,
> except for scheduler details -- where again, we'd think this should be
> an improvement, as the scheduler would now better track load for the
> task (mwifiex RX) in question.
>
> But additional testing on other mwifiex-based systems (RK3399 + PCIE
> 8997) showed the inverse: some throughput drops on similar benchmarks,
> from 110 Mbps to 80 Mbps. (Frankly, both numbers are significantly below
> where we might like...)
>
> Considering we still don't have a full explanation for all the
> performance differences we've been seeing (on either test platform), and
> that at least one of our platforms showed a (smaller) regression, I
> think we might want to do more research before committing to this.
Yeah, I agree and I'll drop this. This is a really weird problem, I hope
you can get to the bottom of it.
--
https://patchwork.kernel.org/project/linux-wireless/list/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
^ permalink raw reply [flat|nested] 5+ messages in thread
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2023-06-09 10:35 [PATCH] wifi: mwifiex: Replace RX workqueues with kthreads Pin-yen Lin
2023-06-09 10:41 ` Kalle Valo
2023-06-09 17:41 ` Pin-yen Lin
2023-06-12 23:47 ` Brian Norris
2023-06-13 5:12 ` Kalle Valo
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