10  * number of "subscribers" to tell whether it has changed since a previous
19  * can later be used to tell whether any new errors have occurred since that
23  * frequently, since we have so few bits to use as a counter.
26  * been sampled since a new value was recorded. That allows us to avoid bumping
27  * the counter if no one has sampled it since the last time an error was
33  * has ever been an error set since it was first initialized.
136  * errseq_check() - Has an error occurred since a particular sample point?
138  * @since: Previously-sampled errseq_t from which to check.
140  * Grab the value that eseq points to, and see if it has changed @since
141  * the given value was sampled. The @since value is not advanced, so there
146 int errseq_check(errseq_t *eseq, errseq_t since)  in errseq_check()  argument
150 	if (likely(cur == since))  in errseq_check()
159  * @since: Pointer to previously-sampled errseq_t to check against and advance.
161  * Grab the eseq value, and see whether it matches the value that @since
166  * "since" value, and return whatever the error portion is set to.
168  * Note that no locking is provided here for concurrent updates to the "since"
176 int errseq_check_and_advance(errseq_t *eseq, errseq_t *since)  in errseq_check_and_advance()  argument
184 	 * to take the lock that protects the "since" value.  in errseq_check_and_advance()
187 	if (old != *since) {  in errseq_check_and_advance()
197 		 * can advance "since" and return an error based on what we  in errseq_check_and_advance()
203 		*since = new;  in errseq_check_and_advance()