diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2025-11-19 20:27:20 +0300 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2025-11-25 21:45:42 +0300 |
| commit | 9da6ccbcea3de1fa704202e3346fe6c0226bfc18 (patch) | |
| tree | b369894a119f091b00be2f1d67722404f40e402a /include/linux | |
| parent | c809f081fe400cb1b9898f4791c0d33146315161 (diff) | |
| download | linux-9da6ccbcea3de1fa704202e3346fe6c0226bfc18.tar.xz | |
sched/mmcid: Implement deferred mode change
When affinity changes cause an increase of the number of CPUs allowed for
tasks which are related to a MM, that might results in a situation where
the ownership mode can go back from per CPU mode to per task mode.
As affinity changes happen with runqueue lock held there is no way to do
the actual mode change and required fixup right there.
Add the infrastructure to defer it to a workqueue. The scheduled work can
race with a fork() or exit(). Whatever happens first takes care of it.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Link: https://patch.msgid.link/20251119172550.216484739@linutronix.de
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/rseq_types.h | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/include/linux/rseq_types.h b/include/linux/rseq_types.h index a3a4f3f10862..81fbb8885e8d 100644 --- a/include/linux/rseq_types.h +++ b/include/linux/rseq_types.h @@ -2,7 +2,9 @@ #ifndef _LINUX_RSEQ_TYPES_H #define _LINUX_RSEQ_TYPES_H +#include <linux/irq_work_types.h> #include <linux/types.h> +#include <linux/workqueue_types.h> #ifdef CONFIG_RSEQ struct rseq; @@ -122,6 +124,8 @@ struct mm_cid_pcpu { * @percpu: Set, when CIDs are in per CPU mode * @transit: Set to MM_CID_TRANSIT during a mode change transition phase * @max_cids: The exclusive maximum CID value for allocation and convergence + * @irq_work: irq_work to handle the affinity mode change case + * @work: Regular work to handle the affinity mode change case * @lock: Spinlock to protect against affinity setting which can't take @mutex * @mutex: Mutex to serialize forks and exits related to this mm * @nr_cpus_allowed: The number of CPUs in the per MM allowed CPUs map. The map @@ -139,6 +143,10 @@ struct mm_mm_cid { unsigned int transit; unsigned int max_cids; + /* Rarely used. Moves @lock and @mutex into the second cacheline */ + struct irq_work irq_work; + struct work_struct work; + raw_spinlock_t lock; struct mutex mutex; |