diff mbox series

ath10k: Add wrapper function to ath10k debug

Message ID 1537766878-11238-1-git-send-email-vnaralas@codeaurora.org (mailing list archive)
State Changes Requested
Delegated to: Kalle Valo
Headers show
Series ath10k: Add wrapper function to ath10k debug | expand

Commit Message

Venkateswara Naralasetty Sept. 24, 2018, 5:27 a.m. UTC
ath10k_dbg() is called in ath10k_process_rx() with huge set of arguments
which is causing CPU overhead even when debug_mask is not set.
Good improvement was observed in the receive side performance when call
to ath10k_dbg() is avoided in the RX path.

Since currently all debug messages are sent via tracing infrastructure,
we cannot entirely avoid calling ath10k_dbg. Therefore, call to
ath10k_dbg() is made conditional based on tracing config in the driver.

Trasmit performance remains unchanged with this patch; below are some
experimental results with this patch and tracing disabled.

mesh mode:

                      w/o this patch          with this patch
        Traffic       TP      CPU Usage      TP      CPU usage

        TCP          840Mbps    76.53%      960Mbps    78.14%
        UDP          1030Mbps   74.58%      1132Mbps   74.31%

Infra mode:

                      w/o this patch          with this patch
        Traffic        TP      CPU Usage      TP      CPU usage

        TCP Rx       1241Mbps   80.89%      1270Mbps   73.50%
        UDP Rx       1433Mbps   81.77%      1472Mbps   72.80%

Tested platform	: IPQ8064
hardware used	: QCA9984
firmware ver	: ver 10.4-3.5.3-00057

Signed-off-by: Kan Yan <kyan@chromium.org>
Signed-off-by: Venkateswara Naralasetty <vnaralas@codeaurora.org>
---
 drivers/net/wireless/ath/ath10k/core.c  |  2 ++
 drivers/net/wireless/ath/ath10k/debug.c | 11 +++++------
 drivers/net/wireless/ath/ath10k/debug.h | 22 ++++++++++++++++------
 3 files changed, 23 insertions(+), 12 deletions(-)

Comments

Kalle Valo Oct. 12, 2018, 3:27 p.m. UTC | #1
Venkateswara Naralasetty <vnaralas@codeaurora.org> writes:

> ath10k_dbg() is called in ath10k_process_rx() with huge set of arguments
> which is causing CPU overhead even when debug_mask is not set.
> Good improvement was observed in the receive side performance when call
> to ath10k_dbg() is avoided in the RX path.
>
> Since currently all debug messages are sent via tracing infrastructure,
> we cannot entirely avoid calling ath10k_dbg. Therefore, call to
> ath10k_dbg() is made conditional based on tracing config in the driver.
>
> Trasmit performance remains unchanged with this patch; below are some
> experimental results with this patch and tracing disabled.
>
> mesh mode:
>
>                       w/o this patch          with this patch
>         Traffic       TP      CPU Usage      TP      CPU usage
>
>         TCP          840Mbps    76.53%      960Mbps    78.14%
>         UDP          1030Mbps   74.58%      1132Mbps   74.31%
>
> Infra mode:
>
>                       w/o this patch          with this patch
>         Traffic        TP      CPU Usage      TP      CPU usage
>
>         TCP Rx       1241Mbps   80.89%      1270Mbps   73.50%
>         UDP Rx       1433Mbps   81.77%      1472Mbps   72.80%
>
> Tested platform	: IPQ8064
> hardware used	: QCA9984
> firmware ver	: ver 10.4-3.5.3-00057
>
> Signed-off-by: Kan Yan <kyan@chromium.org>
> Signed-off-by: Venkateswara Naralasetty <vnaralas@codeaurora.org>

The first Signed-off-by should be the author's, in this case
Venkateswara. If Kan helped to develop the patch you should also add
Co-developed-by:

https://www.kernel.org/doc/html/latest/process/submitting-patches.html#when-to-use-acked-by-cc-and-co-developed-by

> +/* Avoid calling __ath10k_dbg() if debug_mask is not set and tracing
> + * disabled.
> + */
> +#define ath10k_dbg(ar, dbg_mask, fmt, ...)				\
> +do {									\
> +	if (IS_ENABLED(CONFIG_ATH10K_TRACING) ||			\
> +	    (ath10k_debug_mask & dbg_mask))				\
> +		__ath10k_dbg(ar, dbg_mask, fmt, ##__VA_ARGS__);		\
> +} while (0)
>  #endif /* _DEBUG_H_ */

Johannes had an interesting idea to use trace_ath10k_log_dbg_enabled().
Could you investigate if that would work? That way we might get the
performance improvement even when is enabled CONFIG_ATH10K_TRACING (but
actual trace point is disabled, of course).

Documentation/trace/tracepoints.rst has more info about the
trace_*_enabled() function. It does have a special requirement but I'm
not sure if it matters here as we don't care if we loose a message or
two in the beginning:

    "The trace_<tracepoint>() should always be within the block of the
     if (trace_<tracepoint>_enabled()) to prevent races between the
     tracepoint being enabled and the check being seen."
Kan Yan Oct. 15, 2018, 9:56 p.m. UTC | #2
> Johannes had an interesting idea to use trace_ath10k_log_dbg_enabled().
> Could you investigate if that would work? That way we might get the
> performance improvement even when is enabled CONFIG_ATH10K_TRACING (but
> actual trace point is disabled, of course).

That's a good idea. This patch was originally made for Google Wifi's
3.18 kernel and It does use trace_ath10k_log_dbg_enabled():
https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/391891
+#define ath10k_dbg(ar, mask, format, ...)                              \
+       do {                                                            \
+               if (unlikely((ath10k_debug_mask & mask) ||              \
+                             trace_ath10k_log_dbg_enabled())) {        \
+                       __ath10k_dbg(ar, mask, format, ##__VA_ARGS__);  \
+               }                                                       \
+       } while (0)
Venkateswara Naralasetty Nov. 12, 2018, 9:14 a.m. UTC | #3
> -----Original Message-----
> From: ath10k <ath10k-bounces@lists.infradead.org> On Behalf Of Kalle Valo
> Sent: Friday, October 12, 2018 8:58 PM
> To: Venkateswara Naralasetty <vnaralas@codeaurora.org>
> Cc: Kan Yan <kyan@chromium.org>; linux-wireless@vger.kernel.org;
> ath10k@lists.infradead.org
> Subject: [EXTERNAL] Re: [PATCH] ath10k: Add wrapper function to ath10k
> debug
> 
> Venkateswara Naralasetty <vnaralas@codeaurora.org> writes:
> 
> > ath10k_dbg() is called in ath10k_process_rx() with huge set of
> > arguments which is causing CPU overhead even when debug_mask is not
> set.
> > Good improvement was observed in the receive side performance when
> > call to ath10k_dbg() is avoided in the RX path.
> >
> > Since currently all debug messages are sent via tracing
> > infrastructure, we cannot entirely avoid calling ath10k_dbg.
> > Therefore, call to
> > ath10k_dbg() is made conditional based on tracing config in the driver.
> >
> > Trasmit performance remains unchanged with this patch; below are some
> > experimental results with this patch and tracing disabled.
> >
> > mesh mode:
> >
> >                       w/o this patch          with this patch
> >         Traffic       TP      CPU Usage      TP      CPU usage
> >
> >         TCP          840Mbps    76.53%      960Mbps    78.14%
> >         UDP          1030Mbps   74.58%      1132Mbps   74.31%
> >
> > Infra mode:
> >
> >                       w/o this patch          with this patch
> >         Traffic        TP      CPU Usage      TP      CPU usage
> >
> >         TCP Rx       1241Mbps   80.89%      1270Mbps   73.50%
> >         UDP Rx       1433Mbps   81.77%      1472Mbps   72.80%
> >
> > Tested platform	: IPQ8064
> > hardware used	: QCA9984
> > firmware ver	: ver 10.4-3.5.3-00057
> >
> > Signed-off-by: Kan Yan <kyan@chromium.org>
> > Signed-off-by: Venkateswara Naralasetty <vnaralas@codeaurora.org>
> 
> The first Signed-off-by should be the author's, in this case Venkateswara. If
> Kan helped to develop the patch you should also add
> Co-developed-by:
> 
> https://www.kernel.org/doc/html/latest/process/submitting-
> patches.html#when-to-use-acked-by-cc-and-co-developed-by
> 
> > +/* Avoid calling __ath10k_dbg() if debug_mask is not set and tracing
> > + * disabled.
> > + */
> > +#define ath10k_dbg(ar, dbg_mask, fmt, ...)				\
> > +do {									\
> > +	if (IS_ENABLED(CONFIG_ATH10K_TRACING) ||			\
> > +	    (ath10k_debug_mask & dbg_mask))				\
> > +		__ath10k_dbg(ar, dbg_mask, fmt, ##__VA_ARGS__);
> 	\
> > +} while (0)
> >  #endif /* _DEBUG_H_ */
> 
> Johannes had an interesting idea to use trace_ath10k_log_dbg_enabled().
> Could you investigate if that would work? That way we might get the
> performance improvement even when is enabled
> CONFIG_ATH10K_TRACING (but actual trace point is disabled, of course).
> 
Sure I will check on this and send next version.

> Documentation/trace/tracepoints.rst has more info about the
> trace_*_enabled() function. It does have a special requirement but I'm not
> sure if it matters here as we don't care if we loose a message or two in the
> beginning:
> 
>     "The trace_<tracepoint>() should always be within the block of the
>      if (trace_<tracepoint>_enabled()) to prevent races between the
>      tracepoint being enabled and the check being seen."
> 
> --
> Kalle Valo
> 
> _______________________________________________
> ath10k mailing list
> ath10k@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/ath10k
diff mbox series

Patch

diff --git a/drivers/net/wireless/ath/ath10k/core.c b/drivers/net/wireless/ath/ath10k/core.c
index cf3c47b..8460037 100644
--- a/drivers/net/wireless/ath/ath10k/core.c
+++ b/drivers/net/wireless/ath/ath10k/core.c
@@ -37,6 +37,8 @@ 
 #include "coredump.h"
 
 unsigned int ath10k_debug_mask;
+EXPORT_SYMBOL(ath10k_debug_mask);
+
 static unsigned int ath10k_cryptmode_param;
 static bool uart_print;
 static bool skip_otp;
diff --git a/drivers/net/wireless/ath/ath10k/debug.c b/drivers/net/wireless/ath/ath10k/debug.c
index ada29a4..8f305c6 100644
--- a/drivers/net/wireless/ath/ath10k/debug.c
+++ b/drivers/net/wireless/ath/ath10k/debug.c
@@ -2545,8 +2545,8 @@  void ath10k_debug_unregister(struct ath10k *ar)
 #endif /* CONFIG_ATH10K_DEBUGFS */
 
 #ifdef CONFIG_ATH10K_DEBUG
-void ath10k_dbg(struct ath10k *ar, enum ath10k_debug_mask mask,
-		const char *fmt, ...)
+void __ath10k_dbg(struct ath10k *ar, enum ath10k_debug_mask mask,
+		  const char *fmt, ...)
 {
 	struct va_format vaf;
 	va_list args;
@@ -2556,14 +2556,13 @@  void ath10k_dbg(struct ath10k *ar, enum ath10k_debug_mask mask,
 	vaf.fmt = fmt;
 	vaf.va = &args;
 
-	if (ath10k_debug_mask & mask)
-		dev_printk(KERN_DEBUG, ar->dev, "%pV", &vaf);
+	dev_printk(KERN_DEBUG, ar->dev, "%pV", &vaf);
 
 	trace_ath10k_log_dbg(ar, mask, &vaf);
 
 	va_end(args);
 }
-EXPORT_SYMBOL(ath10k_dbg);
+EXPORT_SYMBOL(__ath10k_dbg);
 
 void ath10k_dbg_dump(struct ath10k *ar,
 		     enum ath10k_debug_mask mask,
@@ -2576,7 +2575,7 @@  void ath10k_dbg_dump(struct ath10k *ar,
 
 	if (ath10k_debug_mask & mask) {
 		if (msg)
-			ath10k_dbg(ar, mask, "%s\n", msg);
+			__ath10k_dbg(ar, mask, "%s\n", msg);
 
 		for (ptr = buf; (ptr - buf) < len; ptr += 16) {
 			linebuflen = 0;
diff --git a/drivers/net/wireless/ath/ath10k/debug.h b/drivers/net/wireless/ath/ath10k/debug.h
index 3a6191c..88fead6 100644
--- a/drivers/net/wireless/ath/ath10k/debug.h
+++ b/drivers/net/wireless/ath/ath10k/debug.h
@@ -250,18 +250,18 @@  void ath10k_sta_update_rx_tid_stats_ampdu(struct ath10k *ar,
 #endif /* CONFIG_MAC80211_DEBUGFS */
 
 #ifdef CONFIG_ATH10K_DEBUG
-__printf(3, 4) void ath10k_dbg(struct ath10k *ar,
-			       enum ath10k_debug_mask mask,
-			       const char *fmt, ...);
+__printf(3, 4) void __ath10k_dbg(struct ath10k *ar,
+				 enum ath10k_debug_mask mask,
+				 const char *fmt, ...);
 void ath10k_dbg_dump(struct ath10k *ar,
 		     enum ath10k_debug_mask mask,
 		     const char *msg, const char *prefix,
 		     const void *buf, size_t len);
 #else /* CONFIG_ATH10K_DEBUG */
 
-static inline int ath10k_dbg(struct ath10k *ar,
-			     enum ath10k_debug_mask dbg_mask,
-			     const char *fmt, ...)
+static inline int __ath10k_dbg(struct ath10k *ar,
+			       enum ath10k_debug_mask dbg_mask,
+			       const char *fmt, ...)
 {
 	return 0;
 }
@@ -273,4 +273,14 @@  static inline void ath10k_dbg_dump(struct ath10k *ar,
 {
 }
 #endif /* CONFIG_ATH10K_DEBUG */
+
+/* Avoid calling __ath10k_dbg() if debug_mask is not set and tracing
+ * disabled.
+ */
+#define ath10k_dbg(ar, dbg_mask, fmt, ...)				\
+do {									\
+	if (IS_ENABLED(CONFIG_ATH10K_TRACING) ||			\
+	    (ath10k_debug_mask & dbg_mask))				\
+		__ath10k_dbg(ar, dbg_mask, fmt, ##__VA_ARGS__);		\
+} while (0)
 #endif /* _DEBUG_H_ */