Re: [PATCH] x86/Hyper-V: Fix build error with CONFIG_HYPERV_TSCPAGE=N

From: Vitaly Kuznetsov
Date: Mon Aug 26 2019 - 03:20:39 EST

Sasha Levin <sashal@xxxxxxxxxx> writes:

> On Thu, Aug 22, 2019 at 10:39:46AM +0200, Vitaly Kuznetsov wrote:
>>lantianyu1986@xxxxxxxxx writes:
>>> From: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
>>> Both Hyper-V tsc page and Hyper-V tsc MSR code use variable
>>> hv_sched_clock_offset for their sched clock callback and so
>>> define the variable regardless of CONFIG_HYPERV_TSCPAGE setting.
>>CONFIG_HYPERV_TSCPAGE is gone after my "x86/hyper-v: enable TSC page
>>clocksource on 32bit" patch. Do we still have an issue to fix?
> Yes. Let's get it fixed on older kernels (as such we need to tag this
> one for stable). The 32bit TSC patch won't come in before 5.4 anyway.
> Vitaly, does can you ack this patch? It might require you to re-spin
> your patch.

Sure, no problem,

Acked-by: Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>

I, however, was under the impression the patch fixes the issue with the
newly introduced sched clock:

commit b74e1d61dbc614ff35ef3ad9267c61ed06b09051
Author: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
Date: Wed Aug 14 20:32:16 2019 +0800

clocksource/hyperv: Add Hyper-V specific sched clock function

(and Fixes: tag is missing)

and this is not in mainline as of v5.3-rc6. In tip/timers/core Thomas
already picked my "clocksource/drivers/hyperv: Enable TSC page
clocksource on 32bit" which also resolves the issue.

So my question is - which older/stable kernel do you have in mind?