diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2025-11-19 18:27:22 +0100 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2025-11-25 19:45:42 +0100 |
| commit | 653fda7ae73d8033dedb65537acac0c2c287dc3f (patch) | |
| tree | 767d8491def78517d86b1d064b613888693d9fad /include/linux/rseq.h | |
| parent | 9da6ccbcea3de1fa704202e3346fe6c0226bfc18 (diff) | |
sched/mmcid: Switch over to the new mechanism
Now that all pieces are in place, change the implementations of
sched_mm_cid_fork() and sched_mm_cid_exit() to adhere to the new strict
ownership scheme and switch context_switch() over to use the new
mm_cid_schedin() functionality.
The common case is that there is no mode change required, which makes
fork() and exit() just update the user count and the constraints.
In case that a new user would exceed the CID space limit the fork() context
handles the transition to per CPU mode with mm::mm_cid::mutex held. exit()
handles the transition back to per task mode when the user count drops
below the switch back threshold. fork() might also be forced to handle a
deferred switch back to per task mode, when a affinity change increased the
number of allowed CPUs enough.
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/20251119172550.280380631@linutronix.de
Diffstat (limited to 'include/linux/rseq.h')
| -rw-r--r-- | include/linux/rseq.h | 19 |
1 files changed, 0 insertions, 19 deletions
diff --git a/include/linux/rseq.h b/include/linux/rseq.h index 4c0e8bdd2dd9..2266f4dc77b6 100644 --- a/include/linux/rseq.h +++ b/include/linux/rseq.h @@ -84,24 +84,6 @@ static __always_inline void rseq_sched_set_ids_changed(struct task_struct *t) t->rseq.event.ids_changed = true; } -/* - * Invoked from switch_mm_cid() in context switch when the task gets a MM - * CID assigned. - * - * This does not raise TIF_NOTIFY_RESUME as that happens in - * rseq_sched_switch_event(). - */ -static __always_inline void rseq_sched_set_task_mm_cid(struct task_struct *t, unsigned int cid) -{ - /* - * Requires a comparison as the switch_mm_cid() code does not - * provide a conditional for it readily. So avoid excessive updates - * when nothing changes. - */ - if (t->rseq.ids.mm_cid != cid) - t->rseq.event.ids_changed = true; -} - /* Enforce a full update after RSEQ registration and when execve() failed */ static inline void rseq_force_update(void) { @@ -169,7 +151,6 @@ static inline void rseq_handle_slowpath(struct pt_regs *regs) { } static inline void rseq_signal_deliver(struct ksignal *ksig, struct pt_regs *regs) { } static inline void rseq_sched_switch_event(struct task_struct *t) { } static inline void rseq_sched_set_ids_changed(struct task_struct *t) { } -static inline void rseq_sched_set_task_mm_cid(struct task_struct *t, unsigned int cid) { } static inline void rseq_force_update(void) { } static inline void rseq_virt_userspace_exit(void) { } static inline void rseq_fork(struct task_struct *t, u64 clone_flags) { } |