From: Andi Kleen <ak@linux.intel.com>
To: Alexey Dobriyan <adobriyan@gmail.com>
Cc: linux-kernel@vger.kernel.org, x86@kernel.org, tglx@linutronix.de,
mingo@redhat.com, hpa@zytor.com
Subject: Re: [PATCH 4/5] -march=native: REP STOSB
Date: Fri, 08 Dec 2017 11:08:04 -0800 [thread overview]
Message-ID: <877etxjawb.fsf@linux.intel.com> (raw)
In-Reply-To: <20171207224154.4687-4-adobriyan@gmail.com> (Alexey Dobriyan's message of "Fri, 8 Dec 2017 01:41:53 +0300")
Alexey Dobriyan <adobriyan@gmail.com> writes:
>
> +#ifdef CONFIG_MARCH_NATIVE_REP_STOSB
> +static __always_inline void clear_page(void *page)
> +{
> + uint32_t len = PAGE_SIZE;
> + asm volatile (
> + "rep stosb"
> + : "+D" (page), "+c" (len)
> + : "a" (0)
> + : "memory"
> + );
> +}
clear_page_64 already patches in the equivalent code sequence,
it's clear_page_erms()
It's very doubtful that this patch is worth it.
-Andi
next prev parent reply other threads:[~2017-12-08 19:08 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-12-07 22:41 [PATCH v0 1/5] x86_64: march=native support Alexey Dobriyan
2017-12-07 22:41 ` [PATCH 2/5] -march=native: POPCNT support Alexey Dobriyan
2017-12-07 23:07 ` H. Peter Anvin
2017-12-08 10:09 ` Alexey Dobriyan
2017-12-07 22:41 ` [PATCH 3/5] -march=native: REP MOVSB support Alexey Dobriyan
2017-12-07 22:41 ` [PATCH 4/5] -march=native: REP STOSB Alexey Dobriyan
2017-12-08 19:08 ` Andi Kleen [this message]
2017-12-07 22:41 ` [PATCH 5/5] -march=native: MOVBE support Alexey Dobriyan
2017-12-07 23:32 ` [PATCH v0 1/5] x86_64: march=native support H. Peter Anvin
2017-12-08 9:57 ` Alexey Dobriyan
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