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

Sasha Levin [off-list ref] writes:

On Thu, Aug 22, 2019 at 10:39:46AM +0200, Vitaly Kuznetsov wrote:

quoted

lantianyu1986@gmail.com writes:

quoted

From: Tianyu Lan <redacted>

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@redhat.com>

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

commit b74e1d61dbc614ff35ef3ad9267c61ed06b09051
Author: Tianyu Lan [off-list ref]
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?

-- 
Vitaly