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From: Huang Shijie <shijie@os.amperecomputing.com>
To: catalin.marinas@arm.com
Cc: will@kernel.org, mark.rutland@arm.com, suzuki.poulose@arm.com,
	broonie@kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, anshuman.khandual@arm.com,
	robh@kernel.org, oliver.upton@linux.dev, maz@kernel.org,
	patches@amperecomputing.com,
	Huang Shijie <shijie@os.amperecomputing.com>
Subject: [PATCH 0/4] arm64: an optimization for AmpereOne
Date: Wed, 22 Nov 2023 17:28:51 +0800	[thread overview]
Message-ID: <20231122092855.4440-1-shijie@os.amperecomputing.com> (raw)

0) Background:
   We found that AmpereOne benefits from aggressive prefetches when
   using 4K page size.

1) This patch:
    1.1) adds new WORKAROUND_AMPERE_AC03_PREFETCH capability.
    1.2) uses MIDR_AMPERE1 to filter the processor.
    1.3) uses alternative_if to alternative the code
         for AmpereOne.
    1.4) adds software prefetches for the specific loop.
    	 Also add a macro add_prefetch.

2) Test result:
    In hugetlb or tmpfs, We can get big seqential read performance improvement
    up to 1.3x ~ 1.4x.


Huang Shijie (4):
  extable: add __sort_main_extable
  arm64: alternative: handle the kernel exception table
  arm64: copy_template.S: add loop_for_copy_128_bytes macro
  arm64: add software prefetches for AmpereOne

 arch/arm64/Kconfig.platforms    |  7 +++
 arch/arm64/kernel/alternative.c | 18 +++++++
 arch/arm64/kernel/cpu_errata.c  |  9 ++++
 arch/arm64/lib/copy_template.S  | 87 +++++++++++++++++++++++----------
 arch/arm64/tools/cpucaps        |  1 +
 include/linux/extable.h         |  2 +
 kernel/extable.c                |  8 ++-
 7 files changed, 105 insertions(+), 27 deletions(-)

-- 
2.40.1


             reply	other threads:[~2023-11-22  9:29 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-11-22  9:28 Huang Shijie [this message]
2023-11-22  9:28 ` [PATCH 1/4] extable: add __sort_main_extable Huang Shijie
2023-11-22  9:28 ` [PATCH 2/4] arm64: alternative: handle the kernel exception table Huang Shijie
2023-11-22  9:28 ` [PATCH 3/4] arm64: copy_template.S: add loop_for_copy_128_bytes macro Huang Shijie
2023-11-22  9:28 ` [PATCH 4/4] arm64: add software prefetches for AmpereOne Huang Shijie
2023-11-22 11:34   ` Robin Murphy
2023-11-22  9:48 ` [PATCH 0/4] arm64: an optimization " Will Deacon
2023-11-22 11:40   ` Mark Rutland
2023-11-22 12:11     ` Marc Zyngier
2023-11-23  7:59 ` Linus Walleij

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