diff options
| -rw-r--r-- | kernel/printk/printk.c | 59 |
1 files changed, 31 insertions, 28 deletions
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index 1c048c66d099..60e39cfb2bc0 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -3142,31 +3142,33 @@ static inline void printk_kthreads_check_locked(void) { } * context. * * @next_seq is set to the sequence number after the last available record. - * The value is valid only when there is at least one usable console and all - * usable consoles were flushed. + * The value is valid only when all usable consoles were flushed. It is + * when the function returns true (can do the job) and @try_again parameter + * is set to false, see below. * * @handover will be set to true if a printk waiter has taken over the * console_lock, in which case the caller is no longer holding the * console_lock. Otherwise it is set to false. * - * @any_usable will be set to true if there are any usable consoles. + * @try_again will be set to true when it still makes sense to call this + * function again. The function could do the job, see the return value. + * And some consoles still make progress. * - * Returns true when there was at least one usable console and a record was - * flushed. A returned false indicates there were no records to flush for any - * of the consoles. It may also indicate that there were no usable consoles, - * the context has been lost or there is a panic suitation. Regardless the - * reason, the caller should assume it is not useful to immediately try again. + * Returns true when the function could do the job. Some consoles are usable, + * and there was no takeover and no panic_on_other_cpu(). * * Requires the console_lock. */ static bool console_flush_one_record(bool do_cond_resched, u64 *next_seq, bool *handover, - bool *any_usable) + bool *try_again) { struct console_flush_type ft; - bool any_progress = false; + bool any_usable = false; struct console *con; int cookie; + *try_again = false; + printk_get_console_flush_type(&ft); cookie = console_srcu_read_lock(); @@ -3185,7 +3187,7 @@ static bool console_flush_one_record(bool do_cond_resched, u64 *next_seq, bool * if (!console_is_usable(con, flags, !do_cond_resched)) continue; - *any_usable = true; + any_usable = true; if (flags & CON_NBCON) { progress = nbcon_legacy_emit_next_record(con, handover, cookie, @@ -3201,7 +3203,7 @@ static bool console_flush_one_record(bool do_cond_resched, u64 *next_seq, bool * * is already released. */ if (*handover) - return false; + goto fail; /* Track the next of the highest seq flushed. */ if (printk_seq > *next_seq) @@ -3209,21 +3211,28 @@ static bool console_flush_one_record(bool do_cond_resched, u64 *next_seq, bool * if (!progress) continue; - any_progress = true; + + /* + * An usable console made a progress. There might still be + * pending messages. + */ + *try_again = true; /* Allow panic_cpu to take over the consoles safely. */ if (panic_on_other_cpu()) - goto abandon; + goto fail_srcu; if (do_cond_resched) cond_resched(); } console_srcu_read_unlock(cookie); - return any_progress; + return any_usable; -abandon: +fail_srcu: console_srcu_read_unlock(cookie); +fail: + *try_again = false; return false; } @@ -3252,24 +3261,18 @@ abandon: */ static bool console_flush_all(bool do_cond_resched, u64 *next_seq, bool *handover) { - bool any_usable = false; - bool any_progress; + bool try_again; + bool ret; *next_seq = 0; *handover = false; do { - any_progress = console_flush_one_record(do_cond_resched, next_seq, handover, - &any_usable); + ret = console_flush_one_record(do_cond_resched, next_seq, + handover, &try_again); + } while (try_again); - if (*handover) - return false; - - if (panic_on_other_cpu()) - return false; - } while (any_progress); - - return any_usable; + return ret; } static void __console_flush_and_unlock(void) |