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[173.79.60.52]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-91c47bda586sm103188516d6.8.2026.10.27.07.02.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Oct 2026 07:02:26 -0700 (PDT) X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Subject: Re: [PATCH] mm/mempolicy: recompute automatic interleave weights on memory hotplug From: "Gregory Price (Meta)" To: "David Hildenbrand (Arm)" Cc: Gregory Price , linux-mm@kvack.org, linux-kernel@vger.kernel.org, kernel-team@meta.com, akpm@linux-foundation.org, ziy@nvidia.com, joshua.hahnjy@gmail.com, rakie.kim@sk.com, ying.huang@linux.alibaba.com, honggyu.kim@sk.com, stable@vger.kernel.org In-Reply-To: <13a3b600-8a87-478e-adcc-2425c75f98c6@kernel.org> References: <20261024170415.4121901-1-gourry@gourry.net> <13a3b600-8a87-478e-adcc-2425c75f98c6@kernel.org> Date: Tue, 27 Oct 2026 10:02:25 -0400 Message-Id: <179310974571.2232644.3181896214940432050.b4-reply@b4> X-Mailer: b4 0.17-dev On 2026-10-27 14:04 +0100, David Hildenbrand (Arm) wrote: > >>> + /* > >>> + * HMAT and CXL report a node's bandwidth only when it first gains > >>> + * memory, so recompute the weights whenever N_MEMORY changes. > >>> + */ > >>> + wi_state_refresh(); > >> > >> If the function fails, should we at least pr_warn_once() ? > >> > > > > The only failure state is -ENOMEM, wasn't sure that was worth warning > > on. I actually debated whether to just make this a void function. > > > > I don't have a strong feeling here, but happy to add a warn if you > > prefer it. > > I'd assume we'd at least want to tell the world somehow that something is now > imprecise? > > Or is not updating that harmless? > It's a potential performance regression, but if we just -ENOMEM'd a kernel buffer to hold the weights, there's bigger issues. I'll add a warn. -- ~Gregory