Le Tue, Oct 08, 2024 at 11:54:35AM +0100, Will Deacon a écrit : > On Fri, Sep 27, 2024 at 12:48:59AM +0200, Frederic Weisbecker wrote: > > When a kthread or any other task has an affinity mask that is fully > > offline or unallowed, the scheduler reaffines the task to all possible > > CPUs as a last resort. > > > > This default decision doesn't mix up very well with nohz_full CPUs that > > are part of the possible cpumask but don't want to be disturbed by > > unbound kthreads or even detached pinned user tasks. > > > > Make the fallback affinity setting aware of nohz_full. This applies to > > all architectures supporting nohz_full except arm32. However this > > architecture that overrides the task possible mask is unlikely to be > > willing to integrate new development. > > I'm not sure I understand this last sentence. The possible mask is > overridden for 32-bit tasks on an *arm64* kernel when running on an SoC > featuring some CPUs that can execute only 64-bit tasks. Who is unwilling > to integrate what? Right I've been lazy on that, assuming that nohz_full is a niche, and nohz_full on arm 32 bits tasks must be even more a niche. But I can make it a macro just like task_cpu_possible_mask() so that architectures can override it? Thanks.
