Re: [PATCH v1] PM: sleep: Restore asynchronous device resume optimization

From: Tejun Heo
Date: Wed Feb 07 2024 - 11:40:17 EST


Hello,

On Wed, Feb 07, 2024 at 12:25:46PM +0100, Rafael J. Wysocki wrote:
> The other one is that what happens during async resume does not meet
> the assumptions of commit 5797b1c18919 (for example, it can easily
> produce a chain of interdependent work items longer than 8) and so it
> breaks things.

Ah, that's fascinating. But aren't CPUs all brought up online before devices
are resumed? If so, the max_active should already be way higher than the
WQ_DFL_MIN_ACTIVE. Also, are these multi node NUMA machines? Otherwise, it
really shouldn't affect anything. One easy way to verify would be just
bumping up WQ_DFL_MIN_ACTIVE and see what happens.

Thanks.

--
tejun