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Wed, 12 Aug 2026 19:37:09 -0700 (PDT) Date: Wed, 12 Aug 2026 22:37:06 -0400 From: Gregory Price To: Rakie Kim Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-cxl@vger.kernel.org, nvdimm@lists.linux.dev, ziy@nvidia.com, matthew.brost@intel.com, joshua.hahnjy@gmail.com, byungchul@sk.com, ying.huang@linux.alibaba.com, apopple@nvidia.com, david@kernel.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, dave@stgolabs.net, jic23@kernel.org, dave.jiang@intel.com, alison.schofield@intel.com, vishal.l.verma@intel.com, ira.weiny@intel.com, harry@kernel.org, kernel_team@skhynix.com, honggyu.kim@sk.com, yunjeong.mun@sk.com Subject: Re: [PATCH 0/4] mm/mempolicy: introduce package-aware weighted interleave Message-ID: References: <20260806080936.421-1-rakie.kim@sk.com> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260806080936.421-1-rakie.kim@sk.com> On Thu, Aug 06, 2026 at 05:09:31PM +0900, Rakie Kim wrote: > Package-aware weighted interleave places a task's weighted-interleave > pages on the NUMA nodes of its local package, so that interleave traffic > does not have to cross the interconnect to another package. This keeps > each node's weight aligned with the bandwidth the task actually gets > from it, so effective bandwidth holds up on a system that has more than > one package. (A package is a CPU socket together with the memory > attached to it.) > The only major question I have before I dig into the actual patches is whether you actually need this on a *per-task* basis, rather than simply a *per-process* basis - because that's all this really buys you. You can already do what is described here by simply using a combination of cpuset and mempolicy cpuset.mems = 0,2 mempolicy = weighted interleave --all If this is actually required on a per-task basis, then I agree this concept is reasonable. I just want to make we're grounded on a real use case before we go adding this complexity. ~Gregory