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.
135  * errseq_check() - Has an error occurred since a particular sample point?
137  * @since: Previously-sampled errseq_t from which to check.
139  * Grab the value that eseq points to, and see if it has changed @since
140  * the given value was sampled. The @since value is not advanced, so there
145 int errseq_check(errseq_t *eseq, errseq_t since)  in errseq_check()  argument
149 	if (likely(cur == since))  in errseq_check()
158  * @since: Pointer to previously-sampled errseq_t to check against and advance.
160  * Grab the eseq value, and see whether it matches the value that @since
165  * "since" value, and return whatever the error portion is set to.
167  * Note that no locking is provided here for concurrent updates to the "since"
175 int errseq_check_and_advance(errseq_t *eseq, errseq_t *since)  in errseq_check_and_advance()  argument
183 	 * to take the lock that protects the "since" value.  in errseq_check_and_advance()
186 	if (old != *since) {  in errseq_check_and_advance()
196 		 * can advance "since" and return an error based on what we  in errseq_check_and_advance()
202 		*since = new;  in errseq_check_and_advance()