scsi: fnic: Impose upper limit on max. # of CQs processed per intr

Impose an upper limit on the max number of CQ entries (corresponding to the
copy wq) processed in an interrupt.  Use module parameter to set the limit.

Signed-off-by: Satish Kharat <satishkh@cisco.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/fnic/fnic.h b/drivers/scsi/fnic/fnic.h
index 5c9402c811c9d468e09145a8b1c6f0517f25b646..a3f20ae0add50a2b056df39c6b6de92cb55c38ce 100644 (file)
--- a/drivers/scsi/fnic/fnic.h
+++ b/drivers/scsi/fnic/fnic.h
@@ -128,6 +128,7 @@
        __fnic_set_state_flags(fnicp, st_flags, 1)
 
 extern unsigned int fnic_log_level;
+extern unsigned int io_completions;
 
 #define FNIC_MAIN_LOGGING 0x01
 #define FNIC_FCS_LOGGING 0x02
@@ -196,6 +197,7 @@ enum fnic_state {
 #define FNIC_WQ_MAX 1
 #define FNIC_RQ_MAX 1
 #define FNIC_CQ_MAX (FNIC_WQ_COPY_MAX + FNIC_WQ_MAX + FNIC_RQ_MAX)
+#define FNIC_DFLT_IO_COMPLETIONS 256
 
 struct mempool;
 

diff --git a/drivers/scsi/fnic/fnic_isr.c b/drivers/scsi/fnic/fnic_isr.c
index 4e3a50202e8c5028cc35943004e16af833d0e7eb..da4602b634950e68d57def5bd75bd880c7cf2648 100644 (file)
--- a/drivers/scsi/fnic/fnic_isr.c
+++ b/drivers/scsi/fnic/fnic_isr.c
@@ -51,7 +51,7 @@ static irqreturn_t fnic_isr_legacy(int irq, void *data)
        }
 
        if (pba & (1 << FNIC_INTX_WQ_RQ_COPYWQ)) {
-               work_done += fnic_wq_copy_cmpl_handler(fnic, -1);
+               work_done += fnic_wq_copy_cmpl_handler(fnic, io_completions);
                work_done += fnic_wq_cmpl_handler(fnic, -1);
                work_done += fnic_rq_cmpl_handler(fnic, -1);
 
@@ -72,7 +72,7 @@ static irqreturn_t fnic_isr_msi(int irq, void *data)
        fnic->fnic_stats.misc_stats.last_isr_time = jiffies;
        atomic64_inc(&fnic->fnic_stats.misc_stats.isr_count);
 
-       work_done += fnic_wq_copy_cmpl_handler(fnic, -1);
+       work_done += fnic_wq_copy_cmpl_handler(fnic, io_completions);
        work_done += fnic_wq_cmpl_handler(fnic, -1);
        work_done += fnic_rq_cmpl_handler(fnic, -1);
 
@@ -125,7 +125,7 @@ static irqreturn_t fnic_isr_msix_wq_copy(int irq, void *data)
        fnic->fnic_stats.misc_stats.last_isr_time = jiffies;
        atomic64_inc(&fnic->fnic_stats.misc_stats.isr_count);
 
-       wq_copy_work_done = fnic_wq_copy_cmpl_handler(fnic, -1);
+       wq_copy_work_done = fnic_wq_copy_cmpl_handler(fnic, io_completions);
        vnic_intr_return_credits(&fnic->intr[FNIC_MSIX_WQ_COPY],
                                 wq_copy_work_done,
                                 1 /* unmask intr */,

diff --git a/drivers/scsi/fnic/fnic_main.c b/drivers/scsi/fnic/fnic_main.c
index 25e0414b6cb0778d29fac7f96dd2093f42dcd0a3..1433ba94ea71df43113f058909b2f929498f460e 100644 (file)
--- a/drivers/scsi/fnic/fnic_main.c
+++ b/drivers/scsi/fnic/fnic_main.c
@@ -69,6 +69,11 @@ unsigned int fnic_log_level;
 module_param(fnic_log_level, int, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(fnic_log_level, "bit mask of fnic logging levels");
 
+
+unsigned int io_completions = FNIC_DFLT_IO_COMPLETIONS;
+module_param(io_completions, int, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(io_completions, "Max CQ entries to process at a time");
+
 unsigned int fnic_trace_max_pages = 16;
 module_param(fnic_trace_max_pages, uint, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(fnic_trace_max_pages, "Total allocated memory pages "
@@ -503,7 +508,7 @@ static int fnic_cleanup(struct fnic *fnic)
        }
 
        /* Clean up completed IOs and FCS frames */
-       fnic_wq_copy_cmpl_handler(fnic, -1);
+       fnic_wq_copy_cmpl_handler(fnic, io_completions);
        fnic_wq_cmpl_handler(fnic, -1);
        fnic_rq_cmpl_handler(fnic, -1);