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From: Ley Foon Tan <lftan.linux@gmail.com>
To: Matteo Croce <mcroce@linux.microsoft.com>
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	 linux-arch@vger.kernel.org,
	Paul Walmsley <paul.walmsley@sifive.com>,
	 Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	 Atish Patra <atish.patra@wdc.com>,
	Emil Renner Berthing <kernel@esmil.dk>,
	 Akira Tsukamoto <akira.tsukamoto@gmail.com>,
	Drew Fustini <drew@beagleboard.org>,
	 Bin Meng <bmeng.cn@gmail.com>,
	David Laight <David.Laight@aculab.com>,
	 Guo Ren <guoren@kernel.org>, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v5 3/3] riscv: optimized memset
Date: Thu, 25 Nov 2021 18:56:41 +0800	[thread overview]
Message-ID: <CAFiDJ5-OJzWWR0hSZDsuAmxzxTE7cRR9Bsetpfh5vvrTxzkKPw@mail.gmail.com> (raw)
In-Reply-To: <20210929172234.31620-4-mcroce@linux.microsoft.com>

On Thu, Sep 30, 2021 at 1:56 AM Matteo Croce <mcroce@linux.microsoft.com> wrote:
>
> From: Matteo Croce <mcroce@microsoft.com>
>
> The generic memset is defined as a byte at time write. This is always
> safe, but it's slower than a 4 byte or even 8 byte write.
>
> Write a generic memset which fills the data one byte at time until the
> destination is aligned, then fills using the largest size allowed,
> and finally fills the remaining data one byte at time.
>
> Signed-off-by: Matteo Croce <mcroce@microsoft.com>
> ---
>  arch/riscv/include/asm/string.h |  10 +--
>  arch/riscv/kernel/Makefile      |   1 -
>  arch/riscv/kernel/riscv_ksyms.c |  13 ----
>  arch/riscv/lib/Makefile         |   1 -
>  arch/riscv/lib/memset.S         | 113 --------------------------------
>  arch/riscv/lib/string.c         |  41 ++++++++++++
>  6 files changed, 44 insertions(+), 135 deletions(-)
>  delete mode 100644 arch/riscv/kernel/riscv_ksyms.c
>  delete mode 100644 arch/riscv/lib/memset.S

This patch causes the Linux kernel to hang if compile with LLVM/Clang.
Tested on Qemu.

Steps to compile with Clang:
make CC=clang  defconfig
make CC=clang -j

Boot log:

[    0.000000] Linux version 5.15.4-01003-g23eeaac40da8 (xxxxx@ubuntu)
(clang version 14.0.0 (https://github.com/llvm/llvm-project
6b715e9c4d9cc00f59906d48cd57f4c767229093), GNU ld (GNU Binutils)
2.36.1) #151 SMP Thu Nov 25 18:41:47 +08 2021
[    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80200000
[    0.000000] Machine model: riscv-virtio,qemu
[    0.000000] earlycon: sbi0 at I/O port 0x0 (options '')
[    0.000000] printk: bootconsole [sbi0] enabled
[    0.000000] efi: UEFI not found.

Regards
Ley Foon

_______________________________________________
linux-riscv mailing list
linux-riscv@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-riscv

WARNING: multiple messages have this Message-ID (diff)
From: Ley Foon Tan <lftan.linux@gmail.com>
To: Matteo Croce <mcroce@linux.microsoft.com>
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org,
	linux-arch@vger.kernel.org,
	Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	Atish Patra <atish.patra@wdc.com>,
	Emil Renner Berthing <kernel@esmil.dk>,
	Akira Tsukamoto <akira.tsukamoto@gmail.com>,
	Drew Fustini <drew@beagleboard.org>,
	Bin Meng <bmeng.cn@gmail.com>,
	David Laight <David.Laight@aculab.com>,
	Guo Ren <guoren@kernel.org>, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v5 3/3] riscv: optimized memset
Date: Thu, 25 Nov 2021 18:56:41 +0800	[thread overview]
Message-ID: <CAFiDJ5-OJzWWR0hSZDsuAmxzxTE7cRR9Bsetpfh5vvrTxzkKPw@mail.gmail.com> (raw)
In-Reply-To: <20210929172234.31620-4-mcroce@linux.microsoft.com>

On Thu, Sep 30, 2021 at 1:56 AM Matteo Croce <mcroce@linux.microsoft.com> wrote:
>
> From: Matteo Croce <mcroce@microsoft.com>
>
> The generic memset is defined as a byte at time write. This is always
> safe, but it's slower than a 4 byte or even 8 byte write.
>
> Write a generic memset which fills the data one byte at time until the
> destination is aligned, then fills using the largest size allowed,
> and finally fills the remaining data one byte at time.
>
> Signed-off-by: Matteo Croce <mcroce@microsoft.com>
> ---
>  arch/riscv/include/asm/string.h |  10 +--
>  arch/riscv/kernel/Makefile      |   1 -
>  arch/riscv/kernel/riscv_ksyms.c |  13 ----
>  arch/riscv/lib/Makefile         |   1 -
>  arch/riscv/lib/memset.S         | 113 --------------------------------
>  arch/riscv/lib/string.c         |  41 ++++++++++++
>  6 files changed, 44 insertions(+), 135 deletions(-)
>  delete mode 100644 arch/riscv/kernel/riscv_ksyms.c
>  delete mode 100644 arch/riscv/lib/memset.S

This patch causes the Linux kernel to hang if compile with LLVM/Clang.
Tested on Qemu.

Steps to compile with Clang:
make CC=clang  defconfig
make CC=clang -j

Boot log:

[    0.000000] Linux version 5.15.4-01003-g23eeaac40da8 (xxxxx@ubuntu)
(clang version 14.0.0 (https://github.com/llvm/llvm-project
6b715e9c4d9cc00f59906d48cd57f4c767229093), GNU ld (GNU Binutils)
2.36.1) #151 SMP Thu Nov 25 18:41:47 +08 2021
[    0.000000] OF: fdt: Ignoring memory range 0x80000000 - 0x80200000
[    0.000000] Machine model: riscv-virtio,qemu
[    0.000000] earlycon: sbi0 at I/O port 0x0 (options '')
[    0.000000] printk: bootconsole [sbi0] enabled
[    0.000000] efi: UEFI not found.

Regards
Ley Foon

  reply	other threads:[~2021-11-25 10:57 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-29 17:22 [PATCH v5 0/3] riscv: optimized mem* functions Matteo Croce
2021-09-29 17:22 ` Matteo Croce
2021-09-29 17:22 ` [PATCH v5 1/3] riscv: optimized memcpy Matteo Croce
2021-09-29 17:22   ` Matteo Croce
2021-09-30  1:24   ` Guo Ren
2021-09-30  1:24     ` Guo Ren
2021-09-30  1:36     ` Matteo Croce
2021-09-30  1:36       ` Matteo Croce
2021-09-30 19:43       ` Vineet Gupta
2021-09-30 19:43         ` Vineet Gupta
2021-10-01  8:06         ` David Laight
2021-10-01  8:06           ` David Laight
2021-10-01 11:23   ` Pavel Machek
2021-10-01 11:23     ` Pavel Machek
2021-10-02 17:20     ` Matteo Croce
2021-10-02 17:20       ` Matteo Croce
2021-09-29 17:22 ` [PATCH v5 2/3] riscv: optimized memmove Matteo Croce
2021-09-29 17:22   ` Matteo Croce
2021-09-29 17:22 ` [PATCH v5 3/3] riscv: optimized memset Matteo Croce
2021-09-29 17:22   ` Matteo Croce
2021-11-25 10:56   ` Ley Foon Tan [this message]
2021-11-25 10:56     ` Ley Foon Tan
2021-12-06 20:37     ` Emil Renner Berthing
2021-12-06 20:37       ` Emil Renner Berthing

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