* Re: [RESEND PATCH v2 0/2] Update the watchdog period according to real CPU frequency
[not found] <20250619114805.16968-1-yangyicong@huawei.com>
@ 2025-06-23 23:30 ` Andrew Morton
2025-06-24 10:55 ` Yicong Yang
0 siblings, 1 reply; 2+ messages in thread
From: Andrew Morton @ 2025-06-23 23:30 UTC (permalink / raw)
To: Yicong Yang
Cc: catalin.marinas, will, dianders, sumit.garg, kernelfans,
lecopzer.chen, tglx, song, linux-arm-kernel, jonathan.cameron,
zhanjie9, prime.zeng, yangyicong, linuxarm, Rafael J. Wysocki,
Viresh Kumar, linux-pm
On Thu, 19 Jun 2025 19:48:03 +0800 Yicong Yang <yangyicong@huawei.com> wrote:
> watchdog perf needs architecture to provide method for converting the watchdog
> thresh to counter period. For arm64 we're using the max CPU frequency for
> doing the conversion which is from cpufreq driver. But some cpufreq driver
> are registered lately, for example cppc_cpufreq will be registered at late
> initcall which is after the initialization of watchdog perf (initialized in
> armv8_pmuv3 of device initcall). In such case the period of watchdog will not
> be accurate enough. Fix this by registering a cpufreq notifier and update the
> watchdog period once the cpufreq driver is initialized.
Great, thanks. I'll add these to mm.git for testing.
> arch/arm64/kernel/watchdog_hld.c | 58 ++++++++++++++++++++++++++++++++
> include/linux/nmi.h | 2 ++
> kernel/watchdog_perf.c | 23 +++++++++++++
This is not exactly my comfort zone so additional review would be
appreciated, please. Even though it doesn't touch drivers/cpufreq,
perhaps the developers over there could take a look?
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [RESEND PATCH v2 0/2] Update the watchdog period according to real CPU frequency
2025-06-23 23:30 ` [RESEND PATCH v2 0/2] Update the watchdog period according to real CPU frequency Andrew Morton
@ 2025-06-24 10:55 ` Yicong Yang
0 siblings, 0 replies; 2+ messages in thread
From: Yicong Yang @ 2025-06-24 10:55 UTC (permalink / raw)
To: Andrew Morton
Cc: yangyicong, catalin.marinas, will, dianders, sumit.garg,
kernelfans, lecopzer.chen, tglx, song, linux-arm-kernel,
jonathan.cameron, zhanjie9, prime.zeng, linuxarm,
Rafael J. Wysocki, Viresh Kumar, linux-pm
On 2025/6/24 7:30, Andrew Morton wrote:
> On Thu, 19 Jun 2025 19:48:03 +0800 Yicong Yang <yangyicong@huawei.com> wrote:
>
>> watchdog perf needs architecture to provide method for converting the watchdog
>> thresh to counter period. For arm64 we're using the max CPU frequency for
>> doing the conversion which is from cpufreq driver. But some cpufreq driver
>> are registered lately, for example cppc_cpufreq will be registered at late
>> initcall which is after the initialization of watchdog perf (initialized in
>> armv8_pmuv3 of device initcall). In such case the period of watchdog will not
>> be accurate enough. Fix this by registering a cpufreq notifier and update the
>> watchdog period once the cpufreq driver is initialized.
>
> Great, thanks. I'll add these to mm.git for testing.
>
thanks.
>> arch/arm64/kernel/watchdog_hld.c | 58 ++++++++++++++++++++++++++++++++
>> include/linux/nmi.h | 2 ++
>> kernel/watchdog_perf.c | 23 +++++++++++++
>
> This is not exactly my comfort zone so additional review would be
> appreciated, please. Even though it doesn't touch drivers/cpufreq,
> perhaps the developers over there could take a look?
> .
sure. I've already cc'ed them.
thanks.
^ permalink raw reply [flat|nested] 2+ messages in thread
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2025-06-23 23:30 ` [RESEND PATCH v2 0/2] Update the watchdog period according to real CPU frequency Andrew Morton
2025-06-24 10:55 ` Yicong Yang
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