From: Quinn Tran <qutran@xxxxxxxxxxx>
The storage was not draining io's and the work load
is not spread out across different CPU's evenly. This led to
FW resource counters getting over run on the busy CPU. This
overrun prevented error recovery from happening in a timely
manner.
By switching the counter to atomic, it allows the count to
be little more accurate to prevent the overrun.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: da7c21b72aa8 ("scsi: qla2xxx: Fix command flush during TMF")
Signed-off-by: Quinn Tran <qutran@xxxxxxxxxxx>
Signed-off-by: Nilesh Javali <njavali@xxxxxxxxxxx>
Reviewed-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
---
drivers/scsi/qla2xxx/qla_def.h | 11 ++++++
drivers/scsi/qla2xxx/qla_dfs.c | 10 ++++++
drivers/scsi/qla2xxx/qla_init.c | 8 +++++
drivers/scsi/qla2xxx/qla_inline.h | 57 ++++++++++++++++++++++++++++++-
drivers/scsi/qla2xxx/qla_os.c | 5 +--
5 files changed, 88 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/qla2xxx/qla_def.h b/drivers/scsi/qla2xxx/qla_def.h
index 5882e61141e6..b5ec15bbce99 100644
--- a/drivers/scsi/qla2xxx/qla_def.h
+++ b/drivers/scsi/qla2xxx/qla_def.h
@@ -3770,6 +3770,16 @@ struct qla_fw_resources {
u16 pad;
};
+struct qla_fw_res {
+ u16 iocb_total;
+ u16 iocb_limit;
+ atomic_t iocb_used;
+
+ u16 exch_total;
+ u16 exch_limit;
+ atomic_t exch_used;
+};
+
#define QLA_IOCB_PCT_LIMIT 95
struct qla_buf_pool {
@@ -4829,6 +4839,7 @@ struct qla_hw_data {
u8 edif_post_stop_cnt_down;
struct qla_vp_map *vp_map;
struct qla_nvme_fc_rjt lsrjt;
+ struct qla_fw_res fwres ____cacheline_aligned;
};
#define RX_ELS_SIZE (roundup(sizeof(struct enode) + ELS_MAX_PAYLOAD, SMP_CACHE_BYTES))
diff --git a/drivers/scsi/qla2xxx/qla_dfs.c b/drivers/scsi/qla2xxx/qla_dfs.c
index 1925cc6897b6..f060e593685d 100644
--- a/drivers/scsi/qla2xxx/qla_dfs.c
+++ b/drivers/scsi/qla2xxx/qla_dfs.c
@@ -276,6 +276,16 @@ qla_dfs_fw_resource_cnt_show(struct seq_file *s, void *unused)
seq_printf(s, "estimate exchange used[%d] high water limit [%d] n",
exch_used, ha->base_qpair->fwres.exch_limit);
+
+ if (ql2xenforce_iocb_limit == 2) {
+ iocbs_used = atomic_read(&ha->fwres.iocb_used);
+ exch_used = atomic_read(&ha->fwres.exch_used);
+ seq_printf(s, " estimate iocb2 used [%d] high water limit [%d]\n",
+ iocbs_used, ha->fwres.iocb_limit);
+
+ seq_printf(s, " estimate exchange2 used[%d] high water limit [%d] \n",
+ exch_used, ha->fwres.exch_limit);
+ }
}
return 0;
diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c
index ddc9b54f5703..7faf2109228e 100644
--- a/drivers/scsi/qla2xxx/qla_init.c
+++ b/drivers/scsi/qla2xxx/qla_init.c
@@ -4214,6 +4214,14 @@ void qla_init_iocb_limit(scsi_qla_host_t *vha)
ha->queue_pair_map[i]->fwres.exch_used = 0;
}
}
+
+ ha->fwres.iocb_total = ha->orig_fw_iocb_count;
+ ha->fwres.iocb_limit = (ha->orig_fw_iocb_count * QLA_IOCB_PCT_LIMIT) / 100;
+ ha->fwres.exch_total = ha->orig_fw_xcb_count;
+ ha->fwres.exch_limit = (ha->orig_fw_xcb_count * QLA_IOCB_PCT_LIMIT) / 100;
+
+ atomic_set(&ha->fwres.iocb_used, 0);
+ atomic_set(&ha->fwres.exch_used, 0);
}
void qla_adjust_iocb_limit(scsi_qla_host_t *vha)
diff --git a/drivers/scsi/qla2xxx/qla_inline.h b/drivers/scsi/qla2xxx/qla_inline.h
index 0167e85ba058..0556969f6dc1 100644
--- a/drivers/scsi/qla2xxx/qla_inline.h
+++ b/drivers/scsi/qla2xxx/qla_inline.h
@@ -386,6 +386,7 @@ enum {
RESOURCE_IOCB = BIT_0,
RESOURCE_EXCH = BIT_1, /* exchange */
RESOURCE_FORCE = BIT_2,
+ RESOURCE_HA = BIT_3,
};
static inline int
@@ -393,7 +394,7 @@ qla_get_fw_resources(struct qla_qpair *qp, struct iocb_resource *iores)
{
u16 iocbs_used, i;
u16 exch_used;
- struct qla_hw_data *ha = qp->vha->hw;
+ struct qla_hw_data *ha = qp->hw;
if (!ql2xenforce_iocb_limit) {
iores->res_type = RESOURCE_NONE;
@@ -428,15 +429,69 @@ qla_get_fw_resources(struct qla_qpair *qp, struct iocb_resource *iores)
return -ENOSPC;
}
}
+
+ if (ql2xenforce_iocb_limit == 2) {
+ if ((iores->iocb_cnt + atomic_read(&ha->fwres.iocb_used)) >=
+ ha->fwres.iocb_limit) {
+ iores->res_type = RESOURCE_NONE;
+ return -ENOSPC;
+ }
+
+ if (iores->res_type & RESOURCE_EXCH) {
+ if ((iores->exch_cnt + atomic_read(&ha->fwres.exch_used)) >=
+ ha->fwres.exch_limit) {
+ iores->res_type = RESOURCE_NONE;
+ return -ENOSPC;
+ }
+ }
+ }
+
force:
qp->fwres.iocbs_used += iores->iocb_cnt;
qp->fwres.exch_used += iores->exch_cnt;
+ if (ql2xenforce_iocb_limit == 2) {
+ atomic_add(iores->iocb_cnt, &ha->fwres.iocb_used);
+ atomic_add(iores->exch_cnt, &ha->fwres.exch_used);
+ iores->res_type |= RESOURCE_HA;
+ }
return 0;
}
+/*
+ * decrement to zero. This routine will not decrement below zero
+ * @v: pointer of type atomic_t
+ * @amount: amount to decrement from v
+ */
+static void qla_atomic_dtz(atomic_t *v, int amount)
+{
+ int c, old, dec;
+
+ c = atomic_read(v);
+ for (;;) {
+ dec = c - amount;
+ if (unlikely(dec < 0))
+ dec = 0;
+
+ old = atomic_cmpxchg((v), c, dec);
+ if (likely(old == c))
+ break;
+ c = old;
+ }
+}
+
static inline void
qla_put_fw_resources(struct qla_qpair *qp, struct iocb_resource *iores)
{
+ struct qla_hw_data *ha = qp->hw;
+
+ if (iores->res_type & RESOURCE_HA) {
+ if (iores->res_type & RESOURCE_IOCB)
+ qla_atomic_dtz(&ha->fwres.iocb_used, iores->iocb_cnt);
+
+ if (iores->res_type & RESOURCE_EXCH)
+ qla_atomic_dtz(&ha->fwres.exch_used, iores->exch_cnt);
+ }
+
if (iores->res_type & RESOURCE_IOCB) {
if (qp->fwres.iocbs_used >= iores->iocb_cnt) {
qp->fwres.iocbs_used -= iores->iocb_cnt;
diff --git a/drivers/scsi/qla2xxx/qla_os.c b/drivers/scsi/qla2xxx/qla_os.c
index a18bcc86a21a..7da13607e239 100644
--- a/drivers/scsi/qla2xxx/qla_os.c
+++ b/drivers/scsi/qla2xxx/qla_os.c
@@ -44,10 +44,11 @@ module_param(ql2xfulldump_on_mpifail, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(ql2xfulldump_on_mpifail,
"Set this to take full dump on MPI hang.");
-int ql2xenforce_iocb_limit = 1;
+int ql2xenforce_iocb_limit = 2;
module_param(ql2xenforce_iocb_limit, int, S_IRUGO | S_IWUSR);
MODULE_PARM_DESC(ql2xenforce_iocb_limit,
- "Enforce IOCB throttling, to avoid FW congestion. (default: 1)");
+ "Enforce IOCB throttling, to avoid FW congestion. (default: 2) "
+ "1: track usage per queue, 2: track usage per adapter");
/*
* CT6 CTX allocation cache
--
2.23.1
