scsi: lpfc: Add registration for CPU Offline/Online events
The recent affinitization didn't address cpu offlining/onlining. If an
interrupt vector is shared and the low order cpu owning the vector is
offlined, as interrupts are managed, the vector is taken offline. This
causes the other CPUs sharing the vector will hang as they can't get io
completions.
Correct by registering callbacks with the system for Offline/Online
events. When a cpu is taken offline, its eq, which is tied to an interrupt
vector is found. If the cpu is the "owner" of the vector and if the
eq/vector is shared by other CPUs, the eq is placed into a polled mode.
Additionally, code paths that perform io submission on the "sharing CPUs"
will check the eq state and poll for completion after submission of new io
to a wq that uses the eq.
Similarly, when a cpu comes back online and owns an offlined vector, the eq
is taken out of polled mode and rearmed to start driving interrupts for eq.
Link: https://lore.kernel.org/r/20191105005708.7399-9-jsmart2021@gmail.com
Signed-off-by: Dick Kennedy <dick.kennedy@broadcom.com>
Signed-off-by: James Smart <jsmart2021@gmail.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/lpfc/lpfc.h b/drivers/scsi/lpfc/lpfc.h
index 4559f17..88d5fd9 100644
--- a/drivers/scsi/lpfc/lpfc.h
+++ b/drivers/scsi/lpfc/lpfc.h
@@ -1215,6 +1215,13 @@ struct lpfc_hba {
uint64_t ktime_seg10_min;
uint64_t ktime_seg10_max;
#endif
+
+ struct hlist_node cpuhp; /* used for cpuhp per hba callback */
+ struct timer_list cpuhp_poll_timer;
+ struct list_head poll_list; /* slowpath eq polling list */
+#define LPFC_POLL_HB 1 /* slowpath heartbeat */
+#define LPFC_POLL_FASTPATH 0 /* called from fastpath */
+#define LPFC_POLL_SLOWPATH 1 /* called from slowpath */
};
static inline struct Scsi_Host *