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Tue, 24 Feb 2026 17:04:31 -0800 (PST) From: Askar Safin To: nphamcs@gmail.com Cc: akpm@linux-foundation.org, axelrasmussen@google.com, baohua@kernel.org, bhe@redhat.com, cgroups@vger.kernel.org, chengming.zhou@linux.dev, chrisl@kernel.org, christophe.leroy@csgroup.eu, gourry@gourry.net, hannes@cmpxchg.org, huang.ying.caritas@gmail.com, hughd@google.com, jannh@google.com, joshua.hahnjy@gmail.com, kasong@tencent.com, kernel-team@meta.com, len.brown@intel.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-pm@vger.kernel.org, lorenzo.stoakes@oracle.com, mhocko@kernel.org, muchun.song@linux.dev, npache@redhat.com, osalvador@suse.de, pavel@kernel.org, peterx@redhat.com, pfalcato@suse.de, rafael@kernel.org, riel@surriel.com, roman.gushchin@linux.dev, ryan.roberts@arm.com, shakeel.butt@linux.dev, shikemeng@huaweicloud.com, viro@zeniv.linux.org.uk, weixugc@google.com, yosry.ahmed@linux.dev, yuanchu@google.com, zhengqi.arch@bytedance.com Subject: Re: [PATCH v3 00/20] Virtual Swap Space Date: Wed, 25 Feb 2026 04:04:24 +0300 Message-ID: <20260225010425.2876986-1-safinaskar@gmail.com> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260208215839.87595-1-nphamcs@gmail.com> References: <20260208215839.87595-1-nphamcs@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 104CA4000E X-Stat-Signature: npsc73ez6kbziiofofb8fnz7fk59ndp7 X-Rspam-User: X-Rspamd-Server: rspam04 X-HE-Tag: 1771981473-49949 X-HE-Meta: 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 /IcKVg1E f3ovHEfY8XTC5ZK4oe4cNLWu97wAetKqR6obyk7LHDU4twazR+BbSUZiPqu+otfMQWVh+HTSTUYwLRI/aan1t0IFSlV9Q+1/q7p7yE5UrkBmQrDSMVdp3fR/vTxYwYKIdjfGe1063e1Iun1B4Zpm3IrNqvGOW2ERVsD4CjY9akqHFhrjKm0VA5QqZo+Tk6o4RrggZvelxLcpu6QxQzyfcKKo7hoAy9+IZqliXNfFu8xQG0blXmshtbsTya+6JNC7Oz8Nup+LdoeK7xN6RsEuwJBcEKo/PPUjrxgA+2Uax+z2142gJavUjPMz3DOTeh6DcwE3SQiaa77OtgWl/j4M6/ctMrYdGYKtx6K4I5Xp9mfGRe5zL4NgOPuCnZYObMRloC6RolJrmLyCdaBB4wyi13zFFhzqgEPNG8K27lZnmOC0MVpiWw6wPPkH7lPW7cmb6Dt63gSh2+dJzCsIMmAzB6pH8QmRBCE6/+EsHoNzuhfCurhk= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Nhat Pham : > * Simplify and optimize swapoff: we only have to fault the page in and > have the virtual swap slot points to the page instead of the on-disk > physical swap slot. No need to perform any page table walking. Some time ago on Linux 6.1.124 I typed "swapoff -a". OOM killer started and killed all my apps. And "swapoff" itself eventially failed. So, it seems swapoff is very destructive operation. Please, make swapoff non-destructive. Or create some alternative non-destructive swapoff. Such swapoff should try to swapoff without killing anything. If this is not possible, it simply should return error. I don't think optimizing current dangerous swapoff is right thing to do. -- Askar Safin