diff mbox series

[RFC,05/13] ARCv2: memset: don't prefetch for len == 0 which happens a lot

Message ID 20220222141506.4003433-6-geomatsi@gmail.com
State New
Headers show
Series ARC: handle the lack of ZOL support | expand

Commit Message

Sergey Matyukevich Feb. 22, 2022, 2:14 p.m. UTC 
From: Vineet Gupta <vgupta@kernel.org>

This avoids potential "bleeding" when size == 0 as cache line
would be dirtied (and possibly fetched from other cores) and
due to the same reasons more optimal too.

Signed-off-by: Vineet Gupta <vgupta@kernel.org>
---
 arch/arc/lib/memset-archs.S | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/arc/lib/memset-archs.S b/arch/arc/lib/memset-archs.S
index d2e09fece5bc..d0a5cec4cdca 100644
--- a/arch/arc/lib/memset-archs.S
+++ b/arch/arc/lib/memset-archs.S
@@ -36,12 +36,13 @@ 
 #endif
 
 ENTRY_CFI(memset)
-	PREFETCHW_INSTR	r0, 0	; Prefetch the first write location
 	mov.f	0, r2
 ;;; if size is zero
 	jz.d	[blink]
 	mov	r3, r0		; don't clobber ret val
 
+	PREFETCHW_INSTR	r0, 0	; Prefetch the first write location
+
 ;;; if length < 8
 	brls.d.nt	r2, 8, .Lsmallchunk
 	mov.f	lp_count,r2