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Groups > linux.kernel > #1425902
| From | Andrey Smirnov <andrew.smirnov@gmail.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH v4 4/5] i.MX: system.c: Tweak prefetch settings for performance |
| Date | 2016-06-19 03:20 +0200 |
| Message-ID | <rLzz3-3qF-1@gated-at.bofh.it> (permalink) |
| References | <rLzpn-3nt-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
Update Prefetch Control Register settings to match that of Freescale's Linux tree. As the commit e3addf1b773964eac7f797e8538c69481be4279c states (author Nitin Garg): "... set Prefetch offset to 15, since it improves memcpy performance by 35%. Don't enable Incr double Linefill enable since it adversely affects memcpy performance by about 32MB/s and reads by 90MB/s. Tested with 4K to 16MB sized src and dst aligned buffer..." Those results are also corroborated by our own testing. Acked-by: Arnd Bergmann <arnd@arndb.de> Tested-by: Chris Healy <cphealy@gmail.com> Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com> --- arch/arm/mach-imx/system.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/arch/arm/mach-imx/system.c b/arch/arm/mach-imx/system.c index 76d7ebe..bf7ab77 100644 --- a/arch/arm/mach-imx/system.c +++ b/arch/arm/mach-imx/system.c @@ -111,8 +111,12 @@ void __init imx_init_l2cache(void) val = readl_relaxed(l2x0_base + L310_PREFETCH_CTRL); val |= L310_PREFETCH_CTRL_DBL_LINEFILL | L310_PREFETCH_CTRL_INSTR_PREFETCH | - L310_PREFETCH_CTRL_DATA_PREFETCH | - L310_PREFETCH_CTRL_DBL_LINEFILL_INCR; + L310_PREFETCH_CTRL_DATA_PREFETCH; + + /* Set perfetch offset to improve performance */ + val &= ~L310_PREFETCH_CTRL_OFFSET_MASK; + val |= 15; + writel_relaxed(val, l2x0_base + L310_PREFETCH_CTRL); } -- 2.5.5
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[PATCH v4 0/5] i.MX L2-cache code cleanups and performance tweaks Andrey Smirnov <andrew.smirnov@gmail.com> - 2016-06-19 03:10 +0200 [PATCH v4 2/5] i.MX: system.c: Remove redundant errata 752271 code Andrey Smirnov <andrew.smirnov@gmail.com> - 2016-06-19 03:20 +0200 [PATCH v4 4/5] i.MX: system.c: Tweak prefetch settings for performance Andrey Smirnov <andrew.smirnov@gmail.com> - 2016-06-19 03:20 +0200 [PATCH v4 1/5] i.MX: system.c: Convert goto to if statement Andrey Smirnov <andrew.smirnov@gmail.com> - 2016-06-19 03:20 +0200 [PATCH v4 3/5] i.MX: system.c: Replace magic numbers Andrey Smirnov <andrew.smirnov@gmail.com> - 2016-06-19 03:20 +0200 [PATCH v4 5/5] i.MX: Do not explicitly call l2x0_of_init() Andrey Smirnov <andrew.smirnov@gmail.com> - 2016-06-19 03:20 +0200 Re: [PATCH v4 0/5] i.MX L2-cache code cleanups and performance tweaks Shawn Guo <shawnguo@kernel.org> - 2016-06-21 15:50 +0200
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