From: Sergey Matyukevich <geomatsi@gmail.com>
To: linux-snps-arc@lists.infradead.org
Cc: Vineet Gupta <vgupta@kernel.org>,
Vladimir Isaev <isaev@synopsys.com>,
Sergey Matyukevich <geomatsi@gmail.com>,
Sergey Matyukevich <sergey.matyukevich@synopsys.com>
Subject: [RFC PATCH 05/13] ARCv2: memset: don't prefetch for len == 0 which happens a lot
Date: Tue, 22 Feb 2022 17:14:58 +0300 [thread overview]
Message-ID: <20220222141506.4003433-6-geomatsi@gmail.com> (raw)
In-Reply-To: <20220222141506.4003433-1-geomatsi@gmail.com>
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 --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
--
2.25.1
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next prev parent reply other threads:[~2022-02-22 14:15 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-22 14:14 [RFC PATCH 00/13] ARC: handle the lack of ZOL support Sergey Matyukevich
2022-02-22 14:14 ` [RFC PATCH 01/13] ARC: uaccess: elide unaligned handling if hardware supports Sergey Matyukevich
2022-02-22 14:14 ` [RFC PATCH 02/13] ARC: Kconfig: introduce option to disable ZOL Sergey Matyukevich
2022-02-22 14:14 ` [RFC PATCH 03/13] ARC: uaccess: drop CC_OPTIMIZE_FOR_SIZE Sergey Matyukevich
2022-02-22 14:14 ` [RFC PATCH 04/13] ARC: uaccess: elide ZOL, use double load/stores Sergey Matyukevich
2022-02-22 14:14 ` Sergey Matyukevich [this message]
2022-02-22 14:14 ` [RFC PATCH 06/13] ARCv2: memset: elide unaligned handling if hardware supports Sergey Matyukevich
2022-02-22 14:15 ` [RFC PATCH 07/13] ARCv2: memset: rewrite using double load/stores Sergey Matyukevich
2022-02-22 14:15 ` [RFC PATCH 08/13] ARC: string: use generic C code if no ZOL support Sergey Matyukevich
2022-02-22 14:15 ` [RFC PATCH 09/13] ARC: delay: elide ZOL Sergey Matyukevich
2022-02-22 14:15 ` [RFC PATCH 10/13] ARC: checksum: " Sergey Matyukevich
2022-02-22 14:15 ` [RFC PATCH 11/13] ARC: head: " Sergey Matyukevich
2022-02-22 14:15 ` [RFC PATCH 12/13] ARC: build: inhibit ZOL generation by compiler Sergey Matyukevich
2022-02-22 14:15 ` [RFC PATCH 13/13] ARC: pt_regs: handle the case when ZOL is not supported Sergey Matyukevich
2022-02-28 2:09 ` [RFC PATCH 00/13] ARC: handle the lack of ZOL support Vineet Gupta
2022-03-03 19:22 ` Sergey Matyukevich
2022-03-23 10:09 ` [RFC PATCH 00/13] ARC: handle the lack of ZOL supporty Sergey Matyukevich
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