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Tue, 14 Apr 2026 10:32:52 -0700 (PDT) MIME-Version: 1.0 References: <20260320192735.748051-1-nphamcs@gmail.com> In-Reply-To: From: Nhat Pham Date: Tue, 14 Apr 2026 10:32:40 -0700 X-Gm-Features: AQROBzCXAeCqcScOKrvPHFEfL-AEpSgsJNqZGDJveRabXpX0aHvntrnXQgowKrw Message-ID: Subject: Re: [PATCH v5 00/21] Virtual Swap Space To: Kairui Song Cc: Liam.Howlett@oracle.com, akpm@linux-foundation.org, apopple@nvidia.com, axelrasmussen@google.com, baohua@kernel.org, baolin.wang@linux.alibaba.com, bhe@redhat.com, byungchul@sk.com, cgroups@vger.kernel.org, chengming.zhou@linux.dev, chrisl@kernel.org, corbet@lwn.net, david@kernel.org, dev.jain@arm.com, gourry@gourry.net, hannes@cmpxchg.org, hughd@google.com, jannh@google.com, joshua.hahnjy@gmail.com, lance.yang@linux.dev, lenb@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-pm@vger.kernel.org, lorenzo.stoakes@oracle.com, matthew.brost@intel.com, mhocko@suse.com, muchun.song@linux.dev, npache@redhat.com, pavel@kernel.org, peterx@redhat.com, peterz@infradead.org, pfalcato@suse.de, rafael@kernel.org, rakie.kim@sk.com, roman.gushchin@linux.dev, rppt@kernel.org, ryan.roberts@arm.com, shakeel.butt@linux.dev, shikemeng@huaweicloud.com, surenb@google.com, tglx@kernel.org, vbabka@suse.cz, weixugc@google.com, ying.huang@linux.alibaba.com, yosry.ahmed@linux.dev, yuanchu@google.com, zhengqi.arch@bytedance.com, ziy@nvidia.com, kernel-team@meta.com, riel@surriel.com Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Rspamd-Queue-Id: D135014000E X-Stat-Signature: 3pfqy1sxhyw1majmcjbmj47dbuoqzfgf X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1776187974-114488 X-HE-Meta: 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 lkbZ3Ci8 mIQRwkFiEyQbKGxnDfoawqoALKzXJFzajHezWV8Oxz3VrBqBjVhuDButsHnLwsQL+JB6rftrOE5mSp/hKcXIqm2L8HRU4bsGfpm6ajzxNMIavyVcFx9Nydty+N0647mpPhKSfezE5I+v4xvVUKKMb+kCMbj8+FKs2EDB24YyJhrYArxnS2uX2e7TB7xPjQWNk6TUeYgqhhyb2ChPdMnAaPrEVdXuSNM9joc3Bzh8wx90XTydlGvdp1DXzUy8Cicp3X5fCe9d2sSmUrCIkShPfH+bkvttwpJo+Sdq+MVhbKuoHnMrEIv6pcZki7KiYceByqvdr+Z3AFfYq/SzxwP9MC4YXMb/hy0ueAnd7rbwEgGCeww6wveTHTBcO5G438SsplYcwdOpHJdcfWBCyozeRNJRUXvdgvmZrSZB6hWMvWJVk/xbk79Kz2npHyxdYg6bcca5rjd7vtE8zyNeybCniDbYCmQ+ByXAQ8VvyMEBibV7smiM= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, Apr 14, 2026 at 10:23=E2=80=AFAM Nhat Pham wrot= e: > > * I still think there's a good chance we can *significantly* close the > gap overall between a design with virtual swap and a design without. > It's a bit premature to commit to a vswap-optional route (which to be > completely honest I'm still not confident is possible to satisfy all > of our requirements). And to further note - these benchmark measure, in effect, purely swap overhead. In a production environment with a lot of non-swap work, as long as the gap is close enough I think we would be fine, even for a hostile case like a fast swapfile-backend (I assume SSD swap's bottleneck will be the IO mostly). I will stare at your responses to see if there is other benchmark I can play with, but it would be very helpful if you can share your full suite :)