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[109.81.87.166]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-482b1450fb9sm4258529f8f.14.2026.08.19.01.50.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 19 Aug 2026 01:50:14 -0700 (PDT) Date: Wed, 19 Aug 2026 10:50:13 +0200 From: Michal Hocko To: "David Hildenbrand (Arm)" Cc: Andrew Morton , Leon Hwang , linux-mm@kvack.org, Muchun Song , Oscar Salvador , linux-kernel@vger.kernel.org, Lance Yang Subject: Re: [PATCH] hugetlb: add cond_resched() to __unmap_hugepage_range() Message-ID: References: <20260818135029.93288-1-leon.hwang@linux.dev> <3dadebb3-7e2a-459c-a5e8-b375faf89938@kernel.org> <20260818111756.6b0e347db3170bc22cc3c5af@linux-foundation.org> <2a523945-825c-45a5-a680-37e941e092d3@kernel.org> <20260818115526.654d7311366b66cd031c67e4@linux-foundation.org> <35cca76a-4d3a-451a-b492-dd4423ac3e63@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <35cca76a-4d3a-451a-b492-dd4423ac3e63@kernel.org> X-Rspamd-Queue-Id: 0E16340008 X-Rspamd-Server: rspam10 X-Rspam-User: X-Stat-Signature: 591t13gqs4inhkqp6n57x5usjmquu17j X-HE-Tag: 1787129415-535188 X-HE-Meta: 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 pW9XtAb+ sSMEX0+53CL1tWDOYczyh9cPOGPCMk/4bxoBUQAWhJ3EYZXPryS+7E6v0bZOppHlUQriskEzN6qCuziU94zdWh8zD2of68AXy7t96IFiCflxiwNTG3w2ohanshkKZXg9ZNb/5WPzVgdpwUjpZ4Q8uV92fLBPoVO3kolrAWC3T+RLG66wxGOZLdpjHzD9jLkBGKxpiinS7bC3AF1EiD1JqJ0bM1UlyFZ/uz5VCLDd61EfzYaQEWvrkesb/0ZHuMN5akiyHSG8h4wirbnWxSnSVeB7uAqiCMcgL/DyPr422WcQ0ygZ/tQcebhycGIhYb6IIQiDR6xJBgrxoFwjXPx041KPKD2vyhhB/WoFI7dI9FDlpH5+5t7g/N2saxtYJtHWJO/A6Nll9QevcvnHqmVzetFSjfZXAlwU/yPIYnmEVe5wymQE= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Wed 19-08-26 09:53:25, David Hildenbrand wrote: > On 8/18/26 20:55, Andrew Morton wrote: > > On Tue, 18 Aug 2026 20:21:37 +0200 "David Hildenbrand (Arm)" wrote: > > > >>> > >>> That's pretty bad behavior and we might want to fix it in earlier > >>> kernels. Is PREEMPT_NONE effectively dead in 6.18.x and its > >>> existing users? > >>> > >>> If yes, we do want to fix older kernels then we should merge this. > >>> > >> > >> Okay, but that would be stable-only fixes? > > > > Not understanding. > > > > Maybe you refer to adding a patch to -stable but not to -linus? That's > > against the -stable rules > > (Documentation/process/stable-kernel-rules.rst). > > It's tricky: if a problem only exists in stable (there is nothing to fix in > Linus' tree), then a stable-only fix is acceptable. The crucial quiestion is whether this is something that needs a code fix or a configuration fix. Really fighting for low latencies with PREEMPT_NONE is a kinda lost battle. You might want to play whack a mole... -- Michal Hocko SUSE Labs