Messages in this thread Patch in this message | | | From | John Ogness <> | Subject | [PATCH printk v4 18/27] printk: nbcon: Assign priority based on CPU state | Date | Wed, 3 Apr 2024 00:17:20 +0206 |
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Use the current state of the CPU to determine which priority to assign to the printing context.
The EMERGENCY priority handling is added in a follow-up commit. It will use a per-CPU variable.
Note: nbcon_driver_acquire(), which is used by console drivers to acquire the nbcon console for non-printing activities, will always use NORMAL priority.
Signed-off-by: John Ogness <john.ogness@linutronix.de> Reviewed-by: Petr Mladek <pmladek@suse.com> --- kernel/printk/internal.h | 2 ++ kernel/printk/nbcon.c | 20 ++++++++++++++++++-- 2 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/kernel/printk/internal.h b/kernel/printk/internal.h index acf53c35b7a0..bcf2105a5c5c 100644 --- a/kernel/printk/internal.h +++ b/kernel/printk/internal.h @@ -86,6 +86,7 @@ void nbcon_seq_force(struct console *con, u64 seq); bool nbcon_alloc(struct console *con); void nbcon_init(struct console *con); void nbcon_free(struct console *con); +enum nbcon_prio nbcon_get_default_prio(void); void nbcon_atomic_flush_pending(void); bool nbcon_legacy_emit_next_record(struct console *con, bool *handover, int cookie); @@ -143,6 +144,7 @@ static inline void nbcon_seq_force(struct console *con, u64 seq) { } static inline bool nbcon_alloc(struct console *con) { return false; } static inline void nbcon_init(struct console *con) { } static inline void nbcon_free(struct console *con) { } +static inline enum nbcon_prio nbcon_get_default_prio(void) { return NBCON_PRIO_NONE; } static inline void nbcon_atomic_flush_pending(void) { } static inline bool nbcon_legacy_emit_next_record(struct console *con, bool *handover, int cookie) { return false; } diff --git a/kernel/printk/nbcon.c b/kernel/printk/nbcon.c index 599fff3c0ab3..fe5a96ab1f40 100644 --- a/kernel/printk/nbcon.c +++ b/kernel/printk/nbcon.c @@ -967,6 +967,22 @@ static bool nbcon_atomic_emit_one(struct nbcon_write_context *wctxt) return ctxt->backlog; } +/** + * nbcon_get_default_prio - The appropriate nbcon priority to use for nbcon + * printing on the current CPU + * + * Context: Any context which could not be migrated to another CPU. + * Return: The nbcon_prio to use for acquiring an nbcon console in this + * context for printing. + */ +enum nbcon_prio nbcon_get_default_prio(void) +{ + if (this_cpu_in_panic()) + return NBCON_PRIO_PANIC; + + return NBCON_PRIO_NORMAL; +} + /** * nbcon_legacy_emit_next_record - Print one record for an nbcon console * in legacy contexts @@ -1001,7 +1017,7 @@ bool nbcon_legacy_emit_next_record(struct console *con, bool *handover, stop_critical_timings(); ctxt->console = con; - ctxt->prio = NBCON_PRIO_NORMAL; + ctxt->prio = nbcon_get_default_prio(); progress = nbcon_atomic_emit_one(&wctxt); @@ -1032,7 +1048,7 @@ static bool __nbcon_atomic_flush_pending_con(struct console *con, u64 stop_seq) ctxt->console = con; ctxt->spinwait_max_us = 2000; - ctxt->prio = NBCON_PRIO_NORMAL; + ctxt->prio = nbcon_get_default_prio(); if (!nbcon_context_try_acquire(ctxt)) return false; -- 2.39.2
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