Re: [PATCH 13/17] kernel/cpu: add num_possible_cpus counter
From: Peter Zijlstra <peterz@infradead.org>
Date: 2021-12-21 13:16:25
Also in:
kvm, linux-alpha, linux-crypto, linux-mips, linux-mm, linux-perf-users, linux-riscv, linux-s390, lkml
On Sat, Dec 18, 2021 at 01:20:09PM -0800, Yury Norov wrote:
Similarly to the online cpus, the cpu_possible_mask is actively used in the kernel. This patch adds a counter for possible cpus, so that users that call num_possible_cpus() would know the result immediately, instead of calling the bitmap_weight for the mask underlying.
So what user actually cares about performance here enough to warrant this?
+EXPORT_SYMBOL(set_cpu_possible);
NAK