block, bfq: print SHARED instead of pid for shared queues in logs (1e66413c) · Commits · 戴 / test

block/bfq-iosched.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -2590,6 +2590,16 @@ bfq_merge_bfqqs(struct bfq_data bfqd, struct bfq_io_cq bic,
		* assignment causes no harm).
		*/
		new_bfqq->bic = NULL;
		/*
		* If the queue is shared, the pid is the pid of one of the associated
		* processes. Which pid depends on the exact sequence of merge events
		* the queue underwent. So printing such a pid is useless and confusing
		* because it reports a random pid between those of the associated
		* processes.
		* We mark such a queue with a pid -1, and then print SHARED instead of
		* a pid in logging messages.
		*/
		new_bfqq->pid = -1;
		bfqq->bic = NULL;
		/* release process reference to bfqq */
		bfq_put_queue(bfqq);

block/bfq-iosched.h

+19 −4

Original line number	Diff line number	Diff line
		@@ -32,6 +32,8 @@
		#define BFQ_DEFAULT_GRP_IOPRIO 0
		#define BFQ_DEFAULT_GRP_CLASS IOPRIO_CLASS_BE

		#define MAX_PID_STR_LENGTH 12

		/*
		* Soft real-time applications are extremely more latency sensitive
		* than interactive ones. Over-raise the weight of the former to
		@@ -1016,13 +1018,23 @@ void bfq_add_bfqq_busy(struct bfq_data bfqd, struct bfq_queue bfqq);
		/* --------------- end of interface of B-WF2Q+ ---------------- */

		/* Logging facilities. */
		static inline void bfq_pid_to_str(int pid, char *str, int len)
		{
		if (pid != -1)
		snprintf(str, len, "%d", pid);
		else
		snprintf(str, len, "SHARED-");
		}

		#ifdef CONFIG_BFQ_GROUP_IOSCHED
		struct bfq_group bfqq_group(struct bfq_queue bfqq);

		#define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \
		char pid_str[MAX_PID_STR_LENGTH]; \
		bfq_pid_to_str((bfqq)->pid, pid_str, MAX_PID_STR_LENGTH); \
		blk_add_cgroup_trace_msg((bfqd)->queue, \
		bfqg_to_blkg(bfqq_group(bfqq))->blkcg, \
		"bfq%d%c " fmt, (bfqq)->pid, \
		"bfq%s%c " fmt, pid_str, \
		bfq_bfqq_sync((bfqq)) ? 'S' : 'A', ##args); \
		} while (0)

		@@ -1033,10 +1045,13 @@ struct bfq_group bfqq_group(struct bfq_queue bfqq);

		#else /* CONFIG_BFQ_GROUP_IOSCHED */

		#define bfq_log_bfqq(bfqd, bfqq, fmt, args...) \
		blk_add_trace_msg((bfqd)->queue, "bfq%d%c " fmt, (bfqq)->pid, \
		#define bfq_log_bfqq(bfqd, bfqq, fmt, args...) do { \
		char pid_str[MAX_PID_STR_LENGTH]; \
		bfq_pid_to_str((bfqq)->pid, pid_str, MAX_PID_STR_LENGTH); \
		blk_add_trace_msg((bfqd)->queue, "bfq%s%c " fmt, pid_str, \
		bfq_bfqq_sync((bfqq)) ? 'S' : 'A', \
		##args)
		##args); \
		} while (0)
		#define bfq_log_bfqg(bfqd, bfqg, fmt, args...) do {} while (0)

		#endif /* CONFIG_BFQ_GROUP_IOSCHED */

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