[SCSI] fnic: Fnic Trace Utility
Fnic Trace utility is a tracing functionality built directly into fnic driver
to trace events. The benefit that trace buffer brings to fnic driver is the
ability to see what it happening inside the fnic driver. It also provides the
capability to trace every IO event inside fnic driver to debug panics, hangs
and potentially IO corruption issues. This feature makes it easy to find
problems in fnic driver and it also helps in tracking down strange bugs in a
more manageable way. Trace buffer is shared across all fnic instances for
this implementation.
Signed-off-by: Hiral Patel <hiralpat@cisco.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
diff --git a/drivers/scsi/fnic/fnic_main.c b/drivers/scsi/fnic/fnic_main.c
index fcecbb7..d601ac5 100644
--- a/drivers/scsi/fnic/fnic_main.c
+++ b/drivers/scsi/fnic/fnic_main.c
@@ -68,6 +68,10 @@
module_param(fnic_log_level, int, S_IRUGO|S_IWUSR);
MODULE_PARM_DESC(fnic_log_level, "bit mask of fnic logging levels");
+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 "
+ "for fnic trace buffer");
static struct libfc_function_template fnic_transport_template = {
.frame_send = fnic_send,
@@ -861,6 +865,14 @@
printk(KERN_INFO PFX "%s, ver %s\n", DRV_DESCRIPTION, DRV_VERSION);
+ /* Allocate memory for trace buffer */
+ err = fnic_trace_buf_init();
+ if (err < 0) {
+ printk(KERN_ERR PFX "Trace buffer initialization Failed "
+ "Fnic Tracing utility is disabled\n");
+ fnic_trace_free();
+ }
+
/* Create a cache for allocation of default size sgls */
len = sizeof(struct fnic_dflt_sgl_list);
fnic_sgl_cache[FNIC_SGL_CACHE_DFLT] = kmem_cache_create
@@ -931,6 +943,7 @@
err_create_fnic_sgl_slab_max:
kmem_cache_destroy(fnic_sgl_cache[FNIC_SGL_CACHE_DFLT]);
err_create_fnic_sgl_slab_dflt:
+ fnic_trace_free();
return err;
}
@@ -942,6 +955,7 @@
kmem_cache_destroy(fnic_sgl_cache[FNIC_SGL_CACHE_DFLT]);
kmem_cache_destroy(fnic_io_req_cache);
fc_release_transport(fnic_fc_transport);
+ fnic_trace_free();
}
module_init(fnic_init_module);