Re: [PATCH v4] sched/core: Use zero length to reset cpumasks in sched_setaffinity()

From: Waiman Long
Date: Wed Oct 04 2023 - 08:42:25 EST



On 10/4/23 08:34, Florian Weimer wrote:
* Peter Zijlstra:

Subject: sched: Add CPU_FILL()

Add the CPU_FILL() macros to easily create an all-set cpumask.

FreeBSD also provides this macro with this semantic.

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
My main concer is that obtaining the size of the mask, or at least an
approximiation is not exactly easy. If there's an expectation that
applications reset the mask more often than they do today (I don't have
the full context here), then we'd some decent interface to get the
approriate size.

I believe the macro just use sizeof(cpu_set_t) as the size of the bitmask. It is the same case as in CPU_ZERO().

Regards,
Longman