From 6b941770f0114d42e87875562d5174bc70c5ac65 Mon Sep 17 00:00:00 2001
From: Pablo de Lara <pablo.de.lara.guarch@intel.com>
Date: Tue, 6 Dec 2022 10:59:35 +0000
Subject: [PATCH] Fix for perf scaling on release 1.3
---
lib/include/error.h | 10 +++++++---
lib/include/error.inc | 3 +++
lib/x86_64/error.c | 2 +-
3 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/lib/include/error.h b/lib/include/error.h
index 73d44f51..778df4b1 100644
--- a/lib/include/error.h
+++ b/lib/include/error.h
@@ -32,7 +32,7 @@
* declare global variable to store
* process wide error status
*/
-extern int imb_errno;
+extern volatile int imb_errno;
/**
* @brief API to set error status
@@ -47,8 +47,12 @@ void imb_set_errno(IMB_MGR *mb_mgr, const int errnum)
if (mb_mgr != NULL)
mb_mgr->imb_errno = errnum;
- /* set global error status */
- imb_errno = errnum;
+ /*
+ * set global error status
+ * (only if different, to limit unneeded stores)
+ */
+ if (imb_errno != errnum)
+ imb_errno = errnum;
}
#endif /* ERROR_H */
diff --git a/lib/include/error.inc b/lib/include/error.inc
index 54df265f..5ea53a59 100644
--- a/lib/include/error.inc
+++ b/lib/include/error.inc
@@ -103,7 +103,10 @@ SET_ERRNO_TYPES \
;; Reset global imb_errno to 0
%macro IMB_ERR_CHECK_RESET 0
+ cmp dword [rel imb_errno], 0
+ jz %%do_not_reset
mov dword [rel imb_errno], 0
+%%do_not_reset:
%endmacro
;; Set GP reg and global imb_errno to 0
diff --git a/lib/x86_64/error.c b/lib/x86_64/error.c
index 19189093..24dcded3 100644
--- a/lib/x86_64/error.c
+++ b/lib/x86_64/error.c
@@ -39,7 +39,7 @@
#pragma warning(disable : 4996)
#endif
-IMB_DLL_LOCAL int imb_errno;
+IMB_DLL_LOCAL volatile int imb_errno;
IMB_DLL_LOCAL const int imb_errno_types[] = {
IMB_ERR_NULL_MBMGR,
IMB_ERR_JOB_NULL_SRC,
--
2.34.1