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b=r2laXtpN2/+dlTE6cZ37R2GPzqKnLW8SO4fJywCOcZ4LZ5qaLvahducW4aXC4jzKj rH0SCuEV4+ishUl4E7JlREPWZwH1OESXTQHYQgv96VFzohw+PMXYim3HIVD0xD4E9G Wg8U2HzDDgVXd0dUyIX/6Gb01qDzstIBfHQ5UevZcl/DdS+q6wXoTBLzGXhRn5+H45 hiRWlsNW2nwB8kaXTlA2X4CiklVSUZZpopI102dNT+xxRAcJQbCZIkUCWSCTPm5Mi/ kdGFr2gKO+Q3YdQq/iLMXtJi7pTISjEV6+wXxcf6+7GoMXcB8XRmSM5Ddx8+V8/k4b ukccLcDtgUgUA== Date: Mon, 11 May 2026 22:46:28 +0000 From: Yosry Ahmed To: Nhat Pham Cc: kasong@tencent.com, 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, haowenchao22@gmail.com Subject: Re: [PATCH v6 01/22] mm/swap: decouple swap cache from physical swap infrastructure Message-ID: References: <20260505153854.1612033-1-nphamcs@gmail.com> <20260505153854.1612033-2-nphamcs@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260505153854.1612033-2-nphamcs@gmail.com> X-Rspamd-Server: rspam02 X-Rspamd-Queue-Id: 94AAF40005 X-Rspam-User: X-Stat-Signature: p8zkh1g135yzz8sxoaq3c5tyr5b7is4q X-HE-Tag: 1778539592-986109 X-HE-Meta: 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 J6Ip83U9 XXeRaXZEuiSMrzUi/ffmY2atMLgaeDwv+mdoQraMot9NpEbAJ1exHeQVNembbAV552nAw3F+KBVgf5l0zqWjLyScrAeo/B6AWTANDJJfm3d+ad8F2aiLvzY3tPW4hjDWCmQMvm3rJ10HrxjTDxn7QZ0LtlIhucybyOzJE8xXzrA3D3xCCcH5W67Lcps0Jpr6p+MT4w4t2nLLvu9XWQgxMhI+Yfko0s1OMWfTuyLXdsAAaNT9NpINHNMLl2Nv8gQ40S4D2wapx99iopeeM0NIARNlKbt/j0DGLUzgA0jNrelFDxMyibHanR1ovzUElkNkZp+s2W4/a4Ixh3xYFLzY6tn33h2bw4cP0BniMQATs9f1rFDYYary7CNayakmKHPWoJkYi Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Tue, May 05, 2026 at 08:38:30AM -0700, Nhat Pham wrote: > When we virtualize the swap space, we will manage swap cache at the > virtual swap layer. To prepare for this, decouple swap cache from > physical swap infrastructure. > > We will also remove all the swap cache related helpers of swap table. We > will keep the rest of the swap table infrastructure, which will be > repurposed to serve as the rmap (physical -> virtual swap mapping) > later. I didn't look through the entire series, but let me ask the same high-level question I asked before. Instead of moving things out of the swap table, why not reuse the swap table as the representation of the virtual swap space? Seems like most/all metadata is already moved there in a nice concise format. > > Note that with this patch, we will move to a single global lock to > synchronize swap cache accesses. This is temporarily, as the swap cache > will be re-partitioned in to (virtual) swap clusters once we move the > swap cache to the soon-to-be-introduced virtual swap layer. > > Signed-off-by: Nhat Pham