Add a new sdeb_defer_type enumeration: SDEB_DEFER_POLL for requests
that have REQ_HIPRI set in cmd_flags field. It is expected that
these requests will be polled via the mq_poll entry point which
is driven by calls to blk_poll() in the block layer. Therefore
timer events are not 'wired up' in the normal fashion.
There are still cases with short delays (e.g. < 10 microseconds)
where by the time the command reponse processing occurs, the delay
is already exceeded in which case the code calls scsi_done()
directly. In such cases there is no window for mq_poll() to be
called.
This patch is against the 5.12/scsi-staging branch which includes
a98d6bdf181eb71bf4686666eaf47c642a061642
scsi_debug : iouring iopoll support
which it alters. So this patch is a fix of that patch which fails
in testing.
Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
---
drivers/scsi/scsi_debug.c | 106 +++++++++++++++++++++++++++-----------
1 file changed, 75 insertions(+), 31 deletions(-)
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 746eec521f79..d030c270796b 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -322,17 +322,19 @@ struct sdeb_store_info {
container_of(d, struct sdebug_host_info, dev)
enum sdeb_defer_type {SDEB_DEFER_NONE = 0, SDEB_DEFER_HRT = 1,
- SDEB_DEFER_WQ = 2};
+ SDEB_DEFER_WQ = 2, SDEB_DEFER_POLL = 3};
struct sdebug_defer {
struct hrtimer hrt;
struct execute_work ew;
+ ktime_t cmpl_ts;/* time since boot to complete this cmd */
int sqa_idx; /* index of sdebug_queue array */
int qc_idx; /* index of sdebug_queued_cmd array within sqa_idx */
int hc_idx; /* hostwide tag index */
int issuing_cpu;
bool init_hrt;
bool init_wq;
+ bool init_poll;
bool aborted; /* true when blk_abort_request() already called */
enum sdeb_defer_type defer_t;
};
@@ -5517,40 +5519,62 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
kt -= d;
}
}
- if (!sd_dp->init_hrt) {
- sd_dp->init_hrt = true;
- sqcp->sd_dp = sd_dp;
- hrtimer_init(&sd_dp->hrt, CLOCK_MONOTONIC,
- HRTIMER_MODE_REL_PINNED);
- sd_dp->hrt.function = sdebug_q_cmd_hrt_complete;
- sd_dp->sqa_idx = sqp - sdebug_q_arr;
- sd_dp->qc_idx = k;
+ sd_dp->cmpl_ts = ktime_add(ns_to_ktime(ns_from_boot), kt);
+ if (cmnd->request->cmd_flags & REQ_HIPRI) {
+ if (!sd_dp->init_poll) {
+ sd_dp->init_poll = true;
+ sqcp->sd_dp = sd_dp;
+ sd_dp->sqa_idx = sqp - sdebug_q_arr;
+ sd_dp->qc_idx = k;
+ }
+ sd_dp->defer_t = SDEB_DEFER_POLL;
+ } else {
+ if (!sd_dp->init_hrt) {
+ sd_dp->init_hrt = true;
+ sqcp->sd_dp = sd_dp;
+ hrtimer_init(&sd_dp->hrt, CLOCK_MONOTONIC,
+ HRTIMER_MODE_REL_PINNED);
+ sd_dp->hrt.function = sdebug_q_cmd_hrt_complete;
+ sd_dp->sqa_idx = sqp - sdebug_q_arr;
+ sd_dp->qc_idx = k;
+ }
+ sd_dp->defer_t = SDEB_DEFER_HRT;
+ /* schedule the invocation of scsi_done() for a later time */
+ hrtimer_start(&sd_dp->hrt, kt, HRTIMER_MODE_REL_PINNED);
}
if (sdebug_statistics)
sd_dp->issuing_cpu = raw_smp_processor_id();
- sd_dp->defer_t = SDEB_DEFER_HRT;
- /* schedule the invocation of scsi_done() for a later time */
- hrtimer_start(&sd_dp->hrt, kt, HRTIMER_MODE_REL_PINNED);
} else { /* jdelay < 0, use work queue */
- if (!sd_dp->init_wq) {
- sd_dp->init_wq = true;
- sqcp->sd_dp = sd_dp;
- sd_dp->sqa_idx = sqp - sdebug_q_arr;
- sd_dp->qc_idx = k;
- INIT_WORK(&sd_dp->ew.work, sdebug_q_cmd_wq_complete);
- }
- if (sdebug_statistics)
- sd_dp->issuing_cpu = raw_smp_processor_id();
- sd_dp->defer_t = SDEB_DEFER_WQ;
if (unlikely((sdebug_opts & SDEBUG_OPT_CMD_ABORT) &&
atomic_read(&sdeb_inject_pending)))
sd_dp->aborted = true;
- schedule_work(&sd_dp->ew.work);
- if (unlikely((sdebug_opts & SDEBUG_OPT_CMD_ABORT) &&
- atomic_read(&sdeb_inject_pending))) {
+ sd_dp->cmpl_ts = ns_to_ktime(ns_from_boot);
+ if (cmnd->request->cmd_flags & REQ_HIPRI) {
+ if (!sd_dp->init_poll) {
+ sd_dp->init_poll = true;
+ sqcp->sd_dp = sd_dp;
+ sd_dp->sqa_idx = sqp - sdebug_q_arr;
+ sd_dp->qc_idx = k;
+ }
+ sd_dp->defer_t = SDEB_DEFER_POLL;
+ } else {
+ if (!sd_dp->init_wq) {
+ sd_dp->init_wq = true;
+ sqcp->sd_dp = sd_dp;
+ sd_dp->sqa_idx = sqp - sdebug_q_arr;
+ sd_dp->qc_idx = k;
+ INIT_WORK(&sd_dp->ew.work, sdebug_q_cmd_wq_complete);
+ }
+ sd_dp->defer_t = SDEB_DEFER_WQ;
+ schedule_work(&sd_dp->ew.work);
+ }
+ if (sdebug_statistics)
+ sd_dp->issuing_cpu = raw_smp_processor_id();
+ if (unlikely(sd_dp->aborted)) {
sdev_printk(KERN_INFO, sdp, "abort request tag %d\n", cmnd->request->tag);
blk_abort_request(cmnd->request);
atomic_set(&sdeb_inject_pending, 0);
+ sd_dp->aborted = false;
}
}
if (unlikely((SDEBUG_OPT_Q_NOISE & sdebug_opts) && scsi_result == device_qfull_result))
@@ -7246,30 +7270,47 @@ static int sdebug_map_queues(struct Scsi_Host *shost)
static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
{
- int qc_idx;
+ bool first = true;
int retiring = 0;
+ int num_entries = 0;
+ unsigned int qc_idx;
unsigned long iflags;
+ ktime_t kt_from_boot = ktime_get_boottime();
struct sdebug_queue *sqp;
struct sdebug_queued_cmd *sqcp;
struct scsi_cmnd *scp;
struct sdebug_dev_info *devip;
- int num_entries = 0;
sqp = sdebug_q_arr + queue_num;
do {
spin_lock_irqsave(&sqp->qc_lock, iflags);
- qc_idx = find_first_bit(sqp->in_use_bm, sdebug_max_queue);
- if (unlikely((qc_idx < 0) || (qc_idx >= sdebug_max_queue)))
+ if (first) {
+ qc_idx = find_first_bit(sqp->in_use_bm, sdebug_max_queue);
+ first = false;
+ } else {
+ qc_idx = find_next_bit(sqp->in_use_bm, sdebug_max_queue, qc_idx + 1);
+ }
+ if (unlikely(qc_idx >= sdebug_max_queue))
goto out;
sqcp = &sqp->qc_arr[qc_idx];
scp = sqcp->a_cmnd;
if (unlikely(scp == NULL)) {
- pr_err("scp is NULL, queue_num=%d, qc_idx=%d from %s\n",
+ pr_err("scp is NULL, queue_num=%d, qc_idx=%u from %s\n",
queue_num, qc_idx, __func__);
goto out;
}
+ if (sqcp->sd_dp->defer_t == SDEB_DEFER_POLL) {
+ if (kt_from_boot < sqcp->sd_dp->cmpl_ts) {
+ spin_unlock_irqrestore(&sqp->qc_lock, iflags);
+ goto around;
+ }
+
+ } else { /* ignoring non REQ_HIPRI requests */
+ spin_unlock_irqrestore(&sqp->qc_lock, iflags);
+ goto around;
+ }
devip = (struct sdebug_dev_info *)scp->device->hostdata;
if (likely(devip))
atomic_dec(&devip->num_in_q);
@@ -7280,7 +7321,7 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
sqcp->a_cmnd = NULL;
if (unlikely(!test_and_clear_bit(qc_idx, sqp->in_use_bm))) {
- pr_err("Unexpected completion sqp %p queue_num=%d qc_idx=%d from %s\n",
+ pr_err("Unexpected completion sqp %p queue_num=%d qc_idx=%u from %s\n",
sqp, queue_num, qc_idx, __func__);
goto out;
}
@@ -7302,6 +7343,9 @@ static int sdebug_blk_mq_poll(struct Scsi_Host *shost, unsigned int queue_num)
spin_unlock_irqrestore(&sqp->qc_lock, iflags);
scp->scsi_done(scp); /* callback to mid level */
num_entries++;
+around:
+ if (qc_idx + 1 == sdebug_max_queue)
+ return num_entries;
} while (1);
out:
--
2.25.1
