Re: [PATCH v3 02/23] x86/numa: Add 'nohmat' option

From: Randy Dunlap <rdunlap@infradead.org>
To: Dan Williams <dan.j.williams@intel.com>, akpm@linux-foundation.org
Cc: x86@kernel.org, "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Andy Lutomirski <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	vishal.l.verma@intel.com, ard.biesheuvel@linaro.org,
	linux-mm@kvack.org, linux-nvdimm@lists.01.org,
	joao.m.martins@oracle.com, linux-kernel@vger.kernel.org,
	linux-acpi@vger.kernel.org, dri-devel@lists.freedesktop.org
Subject: Re: [PATCH v3 02/23] x86/numa: Add 'nohmat' option
Date: Fri, 31 Jul 2020 20:51:06 -0700	[thread overview]
Message-ID: <545078f8-d6d3-5db7-02f6-648218513752@infradead.org> (raw)
In-Reply-To: <159625231266.3040297.2759117253481288037.stgit@dwillia2-desk3.amr.corp.intel.com>

On 7/31/20 8:25 PM, Dan Williams wrote:
> Disable parsing of the HMAT for debug, to workaround broken platform
> instances, or cases where it is otherwise not wanted.
> 
> ---
>  arch/x86/mm/numa.c       |    2 ++
>  drivers/acpi/numa/hmat.c |    8 +++++++-
>  include/acpi/acpi_numa.h |    8 ++++++++
>  3 files changed, 17 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> index 87c52822cc44..f3805bbaa784 100644
> --- a/arch/x86/mm/numa.c
> +++ b/arch/x86/mm/numa.c
> @@ -41,6 +41,8 @@ static __init int numa_setup(char *opt)
>  		return numa_emu_cmdline(opt + 5);
>  	if (!strncmp(opt, "noacpi", 6))
>  		disable_srat();
> +	if (!strncmp(opt, "nohmat", 6))
> +		disable_hmat();

Hopefully that will be documented in
Documentation/x86/x86_64/boot-options.rst.

>  	return 0;
>  }
>  early_param("numa", numa_setup);

thanks.
-- 
~Randy