From 94f7531430285b4ec600693f7222c2ca29bd7472 Mon Sep 17 00:00:00 2001 From: "Yury Norov [NVIDIA]" Date: Thu, 15 May 2025 16:58:34 +0000 Subject: [PATCH] x86/resctrl: Optimize cpumask_any_housekeeping() With the lack of cpumask_any_andnot_but(), cpumask_any_housekeeping() has to abuse cpumask_nth() functions. Update cpumask_any_housekeeping() to use the new cpumask_any_but() and cpumask_any_andnot_but(). These two functions understand RESCTRL_PICK_ANY_CPU, which simplifies cpumask_any_housekeeping() significantly. Signed-off-by: Yury Norov [NVIDIA] Signed-off-by: James Morse Signed-off-by: Borislav Petkov (AMD) Reviewed-by: James Morse Reviewed-by: Reinette Chatre Reviewed-by: Shaopeng Tan Reviewed-by: Fenghua Yu Tested-by: Fenghua Yu Tested-by: James Morse Tested-by: Shaopeng Tan Tested-by: Tony Luck Link: https://lore.kernel.org/20250515165855.31452-5-james.morse@arm.com --- arch/x86/kernel/cpu/resctrl/internal.h | 28 +++++++------------------- 1 file changed, 7 insertions(+), 21 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/internal.h b/arch/x86/kernel/cpu/resctrl/internal.h index eaae99602b617..25b61e4667157 100644 --- a/arch/x86/kernel/cpu/resctrl/internal.h +++ b/arch/x86/kernel/cpu/resctrl/internal.h @@ -47,30 +47,16 @@ static inline unsigned int cpumask_any_housekeeping(const struct cpumask *mask, int exclude_cpu) { - unsigned int cpu, hk_cpu; - - if (exclude_cpu == RESCTRL_PICK_ANY_CPU) - cpu = cpumask_any(mask); - else - cpu = cpumask_any_but(mask, exclude_cpu); - - /* Only continue if tick_nohz_full_mask has been initialized. */ - if (!tick_nohz_full_enabled()) - return cpu; - - /* If the CPU picked isn't marked nohz_full nothing more needs doing. */ - if (cpu < nr_cpu_ids && !tick_nohz_full_cpu(cpu)) - return cpu; + unsigned int cpu; /* Try to find a CPU that isn't nohz_full to use in preference */ - hk_cpu = cpumask_nth_andnot(0, mask, tick_nohz_full_mask); - if (hk_cpu == exclude_cpu) - hk_cpu = cpumask_nth_andnot(1, mask, tick_nohz_full_mask); - - if (hk_cpu < nr_cpu_ids) - cpu = hk_cpu; + if (tick_nohz_full_enabled()) { + cpu = cpumask_any_andnot_but(mask, tick_nohz_full_mask, exclude_cpu); + if (cpu < nr_cpu_ids) + return cpu; + } - return cpu; + return cpumask_any_but(mask, exclude_cpu); } struct rdt_fs_context { -- 2.47.2