From: Roman Bolshakov <r.bolshakov@yadro.com>

Date: Fri, 12 Nov 2021 17:54:46 +0300

Subject: scsi: qla2xxx: Format log strings only if needed

Patch-mainline: v5.16-rc5

Git-commit: 69002c8ce914ef0ae22a6ea14b43bb30b9a9a6a8

References: git-fixes

Commit 598a90f2002c ("scsi: qla2xxx: add ring buffer for tracing debug

logs") introduced unconditional log string formatting to ql_dbg() even if

ql_dbg_log event is disabled. It harms performance because some strings are

formatted in fastpath and/or interrupt context.

Link: https://lore.kernel.org/r/20211112145446.51210-1-r.bolshakov@yadro.com

Fixes: 598a90f2002c ("scsi: qla2xxx: add ring buffer for tracing debug logs")

Cc: Rajan Shanmugavelu <rajan.shanmugavelu@oracle.com>

Cc: stable@vger.kernel.org

Signed-off-by: Roman Bolshakov <r.bolshakov@yadro.com>

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

Acked-by: Daniel Wagner <dwagner@suse.de>

---

 drivers/scsi/qla2xxx/qla_dbg.c |    3 +++

 1 file changed, 3 insertions(+)

--- a/drivers/scsi/qla2xxx/qla_dbg.c

+++ b/drivers/scsi/qla2xxx/qla_dbg.c

@@ -2492,6 +2492,9 @@ ql_dbg(uint level, scsi_qla_host_t *vha,

 	struct va_format vaf;

 	char pbuf[64];

+	if (!ql_mask_match(level) && !trace_ql_dbg_log_enabled())

+		return;

+

 	va_start(va, fmt);

 	vaf.fmt = fmt;