From: Peter Zijlstra <peterz@infradead•org>
To: Yury Norov <yury.norov@gmail•com>
Cc: "Juri Lelli" <juri.lelli@redhat•com>,
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Subject: Re: [PATCH 13/17] kernel/cpu: add num_possible_cpus counter
Date: Tue, 21 Dec 2021 14:15:56 +0100 [thread overview]
Message-ID: <YcHTjJxmUntOHKXB@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20211218212014.1315894-14-yury.norov@gmail.com>
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
next prev parent reply other threads:[~2021-12-21 14:22 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-12-18 21:19 [PATCH v2 00/17] lib/bitmap: optimize bitmap_weight() usage Yury Norov
2021-12-18 21:19 ` [PATCH 01/17] all: don't use bitmap_weight() where possible Yury Norov
2021-12-18 22:15 ` Michał Mirosław
2021-12-18 23:28 ` Yury Norov
2021-12-18 21:19 ` [PATCH 02/17] drivers: rename num_*_cpus variables Yury Norov
2021-12-18 21:19 ` [PATCH 03/17] fix open-coded for_each_set_bit() Yury Norov
2021-12-18 21:20 ` [PATCH 04/17] all: replace bitmap_weight with bitmap_empty where appropriate Yury Norov
2021-12-18 21:20 ` [PATCH 05/17] all: replace cpumask_weight with cpumask_empty " Yury Norov
2021-12-18 21:20 ` [PATCH 06/17] all: replace nodes_weight with nodes_empty " Yury Norov
2021-12-18 21:20 ` [PATCH 07/17] lib/bitmap: add bitmap_weight_{cmp, eq, gt, ge, lt, le} functions Yury Norov
2021-12-18 21:20 ` [PATCH 08/17] all: replace bitmap_weight with bitmap_weight_{eq, gt, ge, lt, le} where appropriate Yury Norov
2021-12-20 16:41 ` [PATCH 08/17] all: replace bitmap_weight with bitmap_weight_{eq,gt,ge,lt,le} " Greg Kroah-Hartman
2021-12-18 21:20 ` [PATCH 09/17] lib/cpumask: add cpumask_weight_{eq,gt,ge,lt,le} Yury Norov
2021-12-18 21:20 ` [PATCH 10/17] lib/nodemask: add nodemask_weight_{eq,gt,ge,lt,le} Yury Norov
2021-12-18 21:20 ` [PATCH 11/17] lib/nodemask: add num_node_state_eq() Yury Norov
2021-12-18 21:20 ` [PATCH 12/17] kernel/cpu.c: fix init_cpu_online Yury Norov
2021-12-18 21:20 ` [PATCH 13/17] kernel/cpu: add num_possible_cpus counter Yury Norov
2021-12-21 13:15 ` Peter Zijlstra [this message]
2021-12-18 21:20 ` [PATCH 14/17] kernel/cpu: add num_present_cpu counter Yury Norov
2021-12-21 13:14 ` Peter Zijlstra
2021-12-18 21:20 ` [PATCH 15/17] kernel/cpu: add num_active_cpu counter Yury Norov
2021-12-21 13:13 ` Peter Zijlstra
2021-12-18 21:20 ` [PATCH 16/17] tools/bitmap: sync bitmap_weight Yury Norov
2021-12-18 21:20 ` [PATCH 17/17] MAINTAINERS: add cpumask and nodemask files to BITMAP_API Yury Norov
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