From: Roman Bolshakov r.bolshakov@yadro.com
commit 69002c8ce914ef0ae22a6ea14b43bb30b9a9a6a8 upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -2491,6 +2491,9 @@ 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;