Re: [PATCH] MIPS: SMP: Move the AP sync point before the non-parallel aware functions

[Thomas Bogendoerfer <tsbogend@alpha.franken.de>]

On Mon, May 05, 2025 at 02:57:58PM +0200, Gregory CLEMENT wrote:
> When CONFIG_HOTPLUG_PARALLEL is enabled, the code executing before
> cpuhp_ap_sync_alive() is executed in parallel, while after it is
> serialized. The functions set_cpu_sibling_map() and set_cpu_core_map()
> were not designed to be executed in parallel, so by moving the
> cpuhp_ap_sync_alive() before cpuhp_ap_sync_alive(), we then ensure
> they will be called serialized.
> 
> The measurement done on EyeQ5 did not show any relevant boot time
> increase after applying this patch.
> 
> Reported-by: Huacai Chen <chenhuacai@kernel.org>
> Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>
> ---
> Hello,
> 
> As discussed last week [1], this is the patch that fixes the potential
> issue with the functions set_cpu_sibling_map() and set_cpu_core_map().
> 
> Gregory

applied to mips-next with a Fixes tag added

Thomas.

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