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h=Date:From:To:Cc:Subject:In-Reply-To:References; b=PIWRAjy/5oJNJn/fK01KZLb0cu0dMb+1q6gOXSZv0HgjZigigaf+sKMqSUxCH8qbM iUIjpVKMyv7FlX2YB2MVqGWRLvhKjQdAtJ3YJkwvPOLHyWfTdoovLRULUihsbKP1Qg PEQNTZGJ3nXffRRCZzHNla2ao2+ro4yAtBGKCHfU= Date: Tue, 18 Aug 2026 11:55:26 -0700 From: Andrew Morton To: "David Hildenbrand (Arm)" Cc: 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: <20260818115526.654d7311366b66cd031c67e4@linux-foundation.org> In-Reply-To: <2a523945-825c-45a5-a680-37e941e092d3@kernel.org> 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> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: C36C9C000C X-Rspamd-Server: rspam10 X-Rspam-User: X-Stat-Signature: kaaczwoc5edmzhmgba741jt4nn7zexin X-HE-Tag: 1787079328-449210 X-HE-Meta: U2FsdGVkX1+v5pB+6z44CXAM0eWEpDJ6x4PXnhwBMnWVqLhLhQ2u/ASfdroPLOWSsHoTwcLigr7Q5x5PxyaEZt7Z9+lVHBaoXQLBo4LG1mnTztOvXDxb2RkEPw/1ZS7KxUrX3qFKobsgUSTGgD6wXzWXOabFRmSfNstTl60gWlMh4Uq6bLR7SgUdxSckCB/BU350MZz4Mkhy+WM5rsKi+zUIoW6cjpzIk6UFSks+a0LTo3UJVQzn1iKDVuOfztGefGr6xhjsB5iUO4Rca/JuNLNydBwxCn7iPxbNewEvqGRhjvpA4i8U9EhNIaapjhjzEsYK9UJBKsJrilNc9dRs0eQpf6bYqxsDn9sIbnkPQMAQ2gsQxxMDJRwkJgGoJACFYx6ynUjLMK7kJKvpxEim3qKwJZXcr/3sf1Zzi3NpYarMltXzFH8Veb38o+UgbFlWtbw9GXtLIgkZN3nh98aEtpyu9Eh4lijXQr6btH53bvPg3EGZHggZc9jTbe55Ln5FpSZb2KzpmHoTuTcrVn++2z8VpgFsX2lj+51dCj45fzx7qw9b1gQnJLx2UfWtf1VYsuid3rspTf8uoRvtSJpWoEFGwb2ljmxySScgI4ojug2z6I7MLG3u0aNAX2BD/gQwpr/A+OH3+CCcBNbC72WUNudw2RDUTsnkPaS7291Ho1vQzVrkeEc+rWCOBVPDBTkUSNbCCzpIkUFgbGv023wMLxIhJ/KYl3aDrIQbL+pVijKmHpg2ZpUp6ZDaoGyKY2un7Hf5WkRfIxZKqEvTp8026i1+ccxmblvbC5opLz3SkCMjSIKXceoxK3D11vmc2jwXb6txxhfebAvrkdZabxH6uqCri/OVhwLDEXd0JeCGRO9EHepE80n6KdGoLDnjzOZwnuDbA3ZL8MnKp1ZWGpC4xYPXM9px9zMgs2cf2J6DVmAR/NrLbuNW3+h/rssehaRzo+Mfwt7+Zgd63hHsyCr L7rErFy6 9LFp4LsOHalDDSLOo/6O9pU3D6zKsOmOOu2jx3pxn195x0BGGc3gdle947Uu/pj79EzjNW1djd94g1h2AyOHQMp5u28d1J4wFVH15n2f31sbDC/GLqmhVsUDKDZQphGl5isoJl2WYD/1oIyO/CojDg6D3WpOQ79OgDL8rqmeNwhL1+o9KfgjVp1OelZNyJcvWtHcdMG4ByVOS9uVvn4vioPc1+oRBqwF+VVoNv5mN7nuujfsacHm8wKV0NTgIhdwvnuZnZjYG/TkeakNNOSe1KrrOzeGYL12PiMfedgiD1i9YEc9K9NNm34sI/X4cbdGziawk Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, 18 Aug 2026 20:21:37 +0200 "David Hildenbrand (Arm)" wrote: > >>> if (!ptep) { > >>> address |= last_addr_mask; > >> > >> As Michal just put it: > >> > >> "PREEMPT_NONE is effectivelly dead and most cond_resched will/should be > >> removed. Is there any reason why you are not using full preemption when > >> requiring low latencies?" > >> > >> https://lore.kernel.org/r/aoRnUxUlgf_kRlm8@tiehlicka > > > > 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).