#include "blk.h"
#include "blk-mq.h"
+#include <linux/math64.h>
+
EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_remap);
EXPORT_TRACEPOINT_SYMBOL_GPL(block_rq_remap);
EXPORT_TRACEPOINT_SYMBOL_GPL(block_bio_complete);
}
EXPORT_SYMBOL(blk_delay_queue);
+/**
+ * blk_start_queue_async - asynchronously restart a previously stopped queue
+ * @q: The &struct request_queue in question
+ *
+ * Description:
+ * blk_start_queue_async() will clear the stop flag on the queue, and
+ * ensure that the request_fn for the queue is run from an async
+ * context.
+ **/
+void blk_start_queue_async(struct request_queue *q)
+{
+ queue_flag_clear(QUEUE_FLAG_STOPPED, q);
+ blk_run_queue_async(q);
+}
+EXPORT_SYMBOL(blk_start_queue_async);
+
/**
* blk_start_queue - restart a previously stopped queue
* @q: The &struct request_queue in question
void blk_set_queue_dying(struct request_queue *q)
{
- queue_flag_set_unlocked(QUEUE_FLAG_DYING, q);
+ spin_lock_irq(q->queue_lock);
+ queue_flag_set(QUEUE_FLAG_DYING, q);
+ spin_unlock_irq(q->queue_lock);
if (q->mq_ops)
blk_mq_wake_waiters(q);
struct request *req;
unsigned int request_count = 0;
- blk_queue_split(q, &bio, q->bio_split);
-
/*
* low level driver can indicate that it wants pages above a
* certain limit bounced to low memory (ie for highmem, or even
*/
blk_queue_bounce(q, &bio);
+ blk_queue_split(q, &bio, q->bio_split);
+
if (bio_integrity_enabled(bio) && bio_integrity_prep(bio)) {
bio->bi_error = -EIO;
bio_endio(bio);
if (q->mq_ops) {
if (blk_queue_io_stat(q))
blk_account_io_start(rq, true);
- blk_mq_insert_request(rq, false, true, true);
+ blk_mq_insert_request(rq, false, true, false);
return 0;
}
return 0;
}
+
+/*
+ * Blk IO latency support. We want this to be as cheap as possible, so doing
+ * this lockless (and avoiding atomics), a few off by a few errors in this
+ * code is not harmful, and we don't want to do anything that is
+ * perf-impactful.
+ * TODO : If necessary, we can make the histograms per-cpu and aggregate
+ * them when printing them out.
+ */
+void
+blk_zero_latency_hist(struct io_latency_state *s)
+{
+ memset(s->latency_y_axis_read, 0,
+ sizeof(s->latency_y_axis_read));
+ memset(s->latency_y_axis_write, 0,
+ sizeof(s->latency_y_axis_write));
+ s->latency_reads_elems = 0;
+ s->latency_writes_elems = 0;
+}
+EXPORT_SYMBOL(blk_zero_latency_hist);
+
+ssize_t
+blk_latency_hist_show(struct io_latency_state *s, char *buf)
+{
+ int i;
+ int bytes_written = 0;
+ u_int64_t num_elem, elem;
+ int pct;
+
+ num_elem = s->latency_reads_elems;
+ if (num_elem > 0) {
+ bytes_written += scnprintf(buf + bytes_written,
+ PAGE_SIZE - bytes_written,
+ "IO svc_time Read Latency Histogram (n = %llu):\n",
+ num_elem);
+ for (i = 0;
+ i < ARRAY_SIZE(latency_x_axis_us);
+ i++) {
+ elem = s->latency_y_axis_read[i];
+ pct = div64_u64(elem * 100, num_elem);
+ bytes_written += scnprintf(buf + bytes_written,
+ PAGE_SIZE - bytes_written,
+ "\t< %5lluus%15llu%15d%%\n",
+ latency_x_axis_us[i],
+ elem, pct);
+ }
+ /* Last element in y-axis table is overflow */
+ elem = s->latency_y_axis_read[i];
+ pct = div64_u64(elem * 100, num_elem);
+ bytes_written += scnprintf(buf + bytes_written,
+ PAGE_SIZE - bytes_written,
+ "\t> %5dms%15llu%15d%%\n", 10,
+ elem, pct);
+ }
+ num_elem = s->latency_writes_elems;
+ if (num_elem > 0) {
+ bytes_written += scnprintf(buf + bytes_written,
+ PAGE_SIZE - bytes_written,
+ "IO svc_time Write Latency Histogram (n = %llu):\n",
+ num_elem);
+ for (i = 0;
+ i < ARRAY_SIZE(latency_x_axis_us);
+ i++) {
+ elem = s->latency_y_axis_write[i];
+ pct = div64_u64(elem * 100, num_elem);
+ bytes_written += scnprintf(buf + bytes_written,
+ PAGE_SIZE - bytes_written,
+ "\t< %5lluus%15llu%15d%%\n",
+ latency_x_axis_us[i],
+ elem, pct);
+ }
+ /* Last element in y-axis table is overflow */
+ elem = s->latency_y_axis_write[i];
+ pct = div64_u64(elem * 100, num_elem);
+ bytes_written += scnprintf(buf + bytes_written,
+ PAGE_SIZE - bytes_written,
+ "\t> %5dms%15llu%15d%%\n", 10,
+ elem, pct);
+ }
+ return bytes_written;
+}
+EXPORT_SYMBOL(blk_latency_hist_show);