clocksource/drivers/arm_arch_timer: Fix event stream param in Kconfig
PATCH 1/1 clocksource/drivers/arm_arch_timer: Fix event stream param in Kconfig
From: "Tyler Hicks (Microsoft)" <[email protected]>
Fix the event stream timer command line parameter name that's documented in the Kconfig description for CONFIG_ARM_ARCH_TIMER_EVTSTREAM. It didn't match the command line parameter name that's actually honored in the source code.
--- drivers/clocksource/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
drivers/clocksource/Kconfig +1 -1
@@ -315,7 +315,7 @@ config ARM_ARCH_TIMER_EVTSTREAM executing the wfe instruction at a frequency represented as a power-of-2 divisor of the clock rate. The behaviour can also be overridden on the command line using the - clocksource.arm_arch_timer.evtstream parameter. + clocksource.arm_arch_timer.evtstrm parameter. The main use of the event stream is wfe-based timeouts of userspace locking implementations. It might also be useful for imposing timeout on wfe to safeguard against any programming errors in case an expected
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Hi Tyler,
Quoted 11 lines · Tyler Hicks
From: "Tyler Hicks (Microsoft)" <[email protected]>
Fix the event stream timer command line parameter name that's documented in the
Kconfigdescription forCONFIG_ARM_ARCH_TIMER_EVTSTREAM. It didn't match the command line parameter name that's actually honored in the source code.Reported-by Vijay Balakrishna <[email protected]>Fixes 46fd5c6b3059 ("clocksource/drivers/arm_arch_timer: Control the evtstrm via the cmdline")
No, this really doesn't deserve a Cc: stable. This bit may be wrong, but we have the correct information in the kernel-parameters.txt file, which is authoritative AFAIC.
Quoted 10 lines
Signed-off-by Tyler Hicks (Microsoft) <[email protected]>--- drivers/clocksource/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)drivers/clocksource/Kconfig +0
-0
drivers/clocksource/Kconfig config ARM_ARCH_TIMER_EVTSTREAM · line 321
Quoted 8 lines
drivers/clocksource/Kconfig +1
-1@@ -315,7 +315,7 @@ config ARM_ARCH_TIMER_EVTSTREAM executing the wfe instruction at a frequency represented as a power-of-2 divisor of the clock rate. The behaviour can also be overridden on the command line using the - clocksource.arm_arch_timer.evtstream parameter. + clocksource.arm_arch_timer.evtstrm parameter. The main use of the event stream is wfe-based timeouts of userspace locking implementations. It might also be useful for imposing timeout on wfe to safeguard against any programming errors in case an expected
With this tag dropped,
M.
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Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list [email protected] http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
Quoted 12 lines · Marc Zyngier
Hi Tyler,
Quoted 8 lines · Tyler Hicks
From: "Tyler Hicks (Microsoft)" <[email protected]>
Fix the event stream timer command line parameter name that's documented in the
Kconfigdescription forCONFIG_ARM_ARCH_TIMER_EVTSTREAM. It didn't match the command line parameter name that's actually honored in the source code.
Quoted 7 lines
Quoted 3 lines
Reported-by Vijay Balakrishna <[email protected]>Fixes 46fd5c6b3059 ("clocksource/drivers/arm_arch_timer: Control the evtstrm via the cmdline")No, this really doesn't deserve a Cc: stable. This bit may be wrong, but we have the correct information in the kernel-parameters.txt file, which is authoritative AFAIC.
Thanks for the review!
I added the stable tag because it caused an actual waste of time in an investigation. Upon discovering this option, I didn't notice the subtle difference in cmdline parameter name from the Kconfig, to the kernel-parameters.txt file and the code. I ran long-running stress tests with the incorrect parameter name copied and pasted from the Kconfig. This error resulted in a bad data point in the investigation and it took a second set of eyes (Vijay's) to uncover my mistake days later when we were trying to reconcile the bad data point with other good data points.
It is no big deal if it is merged with the tag dropped but I wanted to provide my reasoning of why I personally felt this was a more than just a comment typo fix or something along those lines. Thanks, again!
Tyler
Quoted 28 lines
Quoted 11 lines
Signed-off-by Tyler Hicks (Microsoft) <[email protected]>--- drivers/clocksource/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)drivers/clocksource/Kconfig +0
-0drivers/clocksource/Kconfig config ARM_ARCH_TIMER_EVTSTREAM · line 321
Quoted 8 lines
drivers/clocksource/Kconfig +1
-1@@ -315,7 +315,7 @@ config ARM_ARCH_TIMER_EVTSTREAM executing the wfe instruction at a frequency represented as a power-of-2 divisor of the clock rate. The behaviour can also be overridden on the command line using the - clocksource.arm_arch_timer.evtstream parameter. + clocksource.arm_arch_timer.evtstrm parameter. The main use of the event stream is wfe-based timeouts of userspace locking implementations. It might also be useful for imposing timeout on wfe to safeguard against any programming errors in case an expectedWith this tag dropped,
Acked-by Marc Zyngier <[email protected]>M.Signature · 1 line
Without deviation from the norm, progress is not possible.
Hi Tyler,
Quoted 24 lines · Tyler Hicks (Microsoft)
Quoted 12 lines · Marc Zyngier
Hi Tyler,
Quoted 8 lines · Tyler Hicks
From: "Tyler Hicks (Microsoft)" <[email protected]>
Fix the event stream timer command line parameter name that's documented in the
Kconfigdescription forCONFIG_ARM_ARCH_TIMER_EVTSTREAM. It didn't match the command line parameter name that's actually honored in the source code.Quoted 7 lines
Quoted 3 lines
Reported-by Vijay Balakrishna <[email protected]>Fixes 46fd5c6b3059 ("clocksource/drivers/arm_arch_timer: Control the evtstrm via the cmdline")No, this really doesn't deserve a Cc: stable. This bit may be wrong, but we have the correct information in the kernel-parameters.txt file, which is authoritative AFAIC.
Thanks for the review!
Quoted 8 lines
I added the stable tag because it caused an actual waste of time in an investigation. Upon discovering this option, I didn't notice the subtle difference in cmdline parameter name from the
Kconfig, to the kernel-parameters.txt file and the code. I ran long-running stress tests with the incorrect parameter name copied and pasted from theKconfig. This error resulted in a bad data point in the investigation and it took a second set of eyes (Vijay's) to uncover my mistake days later when we were trying to reconcile the bad data point with other good data points.
I appreciate this has caused a certain waste of time, but the rules for stable inclusion are pretty clear: it has to be a runtime bug. Documentation bugs, as irritating as they are, do not fall into this category (it really *is* a typo).
Thanks,
M.
Signature · 1 line
Without deviation from the norm, progress is not possible.