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[173.79.60.52]) by smtp.gmail.com with ESMTPSA id 6a1803df08f44-91b99ed3e9fsm78354316d6.29.2026.10.15.09.02.25 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 15 Oct 2026 09:02:25 -0700 (PDT) Date: Thu, 15 Oct 2026 12:02:23 -0400 From: Gregory Price To: Li Zhe Cc: akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, joshua.hahnjy@gmail.com, ziy@nvidia.com, mingo@redhat.com, peterz@infradead.org, mgorman@suse.de, riel@redhat.com, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, vschneid@redhat.com, kprateek.nayak@amd.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH 3/6] sched/numa: fix scan-period adjustment for shared faults Message-ID: References: <20261014094347.99157-1-lizhe.67@bytedance.com> <20261014094347.99157-4-lizhe.67@bytedance.com> <9b9e6c92-a291-48b4-a128-c31bc718db7a@bytedance.com> Precedence: bulk X-Mailing-List: linux-kernel@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: <9b9e6c92-a291-48b4-a128-c31bc718db7a@bytedance.com> On Thu, Oct 15, 2026 at 07:39:42PM +0800, Li Zhe wrote: > So I think I should separate the severe fixes from the heuristic changes. This would be appreciated. The heuristic changes that aren't obvious Fixes: should not be lumped in. > For the latter, I will narrow the next version to NUMA balancing behavior > that is specific to memory tiering, instead of trying to justify the > changes as general improvements for normal NUMA balancing workloads. For heuristic changes, please try to generate some kind of data that demonstrate the behavior being changed. Some of this scan-period tweaking is very difficult to understand how it will affect end-users without examples. There's risk of introducing unexpected regressions when we change these heuristics. For example - the recent shmem scanning fix. Fixing that resulted in 4-5 other regressions, despite being a "correctness" change. ~Gregory