The following commit has been merged into the x86/cache branch of tip:
Commit-ID: 94f7531430285b4ec600693f7222c2ca29bd7472
Gitweb: https://git.kernel.org/tip/94f7531430285b4ec600693f7222c2ca29bd7472
Author: Yury Norov [NVIDIA] <yury.norov@gmail.com>
AuthorDate: Thu, 15 May 2025 16:58:34
Committer: Borislav Petkov (AMD) <bp@alien8.de>
CommitterDate: Thu, 15 May 2025 20:53:26 +02:00
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] <yury.norov@gmail.com>
Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: James Morse <james.morse@arm.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: Fenghua Yu <fenghuay@nvidia.com>
Tested-by: James Morse <james.morse@arm.com>
Tested-by: Shaopeng Tan <tan.shaopeng@jp.fujitsu.com>
Tested-by: Tony Luck <tony.luck@intel.com>
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 eaae996..25b61e4 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 {