From: Ganesh Mahendran <opensource.ganesh@gmail.com>
To: liucai1123@thundersoft.com
Cc: Ganesh Mahendran <opensource.ganesh@gmail.com>, stable@vger.kernel.org
Subject: [PATCH] Revert "arm64: Increase the max granular size"
Date: Wed, 16 Mar 2016 17:37:29 +0800 [thread overview]
Message-ID: <1458121049-12214-1-git-send-email-opensource.ganesh@gmail.com> (raw)
Reverts commit 97303480753e ("arm64: Increase the max granular size").
The commit 97303480753e ("arm64: Increase the max granular size") will
degrade system performente in some cpus.
We test wifi network throughput with iperf on Qualcomm msm8996 CPU:
----------------
run on host:
# iperf -s
run on device:
# iperf -c <device-ip-addr> -t 100 -i 1
----------------
Test result:
----------------
with commit 97303480753e ("arm64: Increase the max granular size"):
172MBits/sec
without commit 97303480753e ("arm64: Increase the max granular size"):
230MBits/sec
----------------
Some module like slab/net will use the L1_CACHE_SHIFT, so if we do not
set the parameter correctly, it may affect the system performance.
So revert the commit.
Cc: stable@vger.kernel.org
Signed-off-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
---
arch/arm64/include/asm/cache.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/cache.h b/arch/arm64/include/asm/cache.h
index 5082b30..bde4499 100644
--- a/arch/arm64/include/asm/cache.h
+++ b/arch/arm64/include/asm/cache.h
@@ -18,7 +18,7 @@
#include <asm/cachetype.h>
-#define L1_CACHE_SHIFT 7
+#define L1_CACHE_SHIFT 6
#define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT)
/*
--
1.7.9.5
next reply other threads:[~2016-03-16 9:56 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-16 9:37 Ganesh Mahendran [this message]
-- strict thread matches above, loose matches on Subject: below --
2016-03-16 9:32 [PATCH] Revert "arm64: Increase the max granular size" Ganesh Mahendran
2016-03-16 10:07 ` Will Deacon
2016-03-16 13:06 ` Timur Tabi
2016-03-16 14:03 ` Mark Rutland
2016-03-16 14:35 ` Will Deacon
2016-03-16 14:54 ` Mark Rutland
2016-03-16 14:18 ` Catalin Marinas
2016-03-16 15:26 ` Timur Tabi
2016-03-17 14:27 ` Catalin Marinas
2016-03-17 14:49 ` Timur Tabi
2016-03-17 15:37 ` Catalin Marinas
2016-03-17 16:03 ` Marc Zyngier
2016-03-17 18:07 ` Andrew Pinski
2016-03-17 18:34 ` Timur Tabi
2016-03-17 18:37 ` Catalin Marinas
2016-03-18 21:05 ` Chalamarla, Tirumalesh
2016-03-21 1:56 ` Ganesh Mahendran
2016-03-21 17:14 ` Catalin Marinas
2016-03-21 17:23 ` Will Deacon
2016-03-21 17:33 ` Catalin Marinas
2016-03-21 17:39 ` Chalamarla, Tirumalesh
2016-03-16 9:27 Ganesh Mahendran
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