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Message-ID: <6c8ed42d-ea71-c11e-2689-c4fc23845ccf@amd.com>
Date:   Tue, 1 Aug 2023 08:05:00 +0530
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Subject: Re: [PATCH RESEND 0/4] memory tiering: calculate abstract distance
 based on ACPI HMAT
Content-Language: en-US
To:     Andrew Morton <akpm@linux-foundation.org>,
        Alistair Popple <apopple@nvidia.com>
Cc:     Huang Ying <ying.huang@intel.com>, linux-mm@kvack.org,
        linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org,
        nvdimm@lists.linux.dev, linux-acpi@vger.kernel.org,
        "Aneesh Kumar K . V" <aneesh.kumar@linux.ibm.com>,
        Wei Xu <weixugc@google.com>,
        Dan Williams <dan.j.williams@intel.com>,
        Dave Hansen <dave.hansen@intel.com>,
        Davidlohr Bueso <dave@stgolabs.net>,
        Johannes Weiner <hannes@cmpxchg.org>,
        Jonathan Cameron <Jonathan.Cameron@huawei.com>,
        Michal Hocko <mhocko@kernel.org>,
        Yang Shi <shy828301@gmail.com>,
        Rafael J Wysocki <rafael.j.wysocki@intel.com>
References: <20230721012932.190742-1-ying.huang@intel.com>
 <875y6dj3ok.fsf@nvdebian.thelocal>
 <20230724105818.6f7b10fc8c318ea5aae9e188@linux-foundation.org>
From:   Bharata B Rao <bharata@amd.com>
In-Reply-To: <20230724105818.6f7b10fc8c318ea5aae9e188@linux-foundation.org>
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On 24-Jul-23 11:28 PM, Andrew Morton wrote:
> On Fri, 21 Jul 2023 14:15:31 +1000 Alistair Popple <apopple@nvidia.com> wrote:
> 
>> Thanks for this Huang, I had been hoping to take a look at it this week
>> but have run out of time. I'm keen to do some testing with it as well.
> 
> Thanks.  I'll queue this in mm-unstable for some testing.  Detailed
> review and testing would be appreciated.

I gave this series a try on a 2P system with 2 CXL cards. I don't trust the
bandwidth and latency numbers reported by HMAT here, but FWIW, this patchset
puts the CXL nodes on a lower tier than DRAM nodes.

Regards,
Bharata.