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AJvYcCUm7EhBgKoMDlZaQqCskr/zy5jWbxuqyswNbCNCAKCgK7tj82qbXkxV1OdhDpPVEirggTt34Y+jYOs35zokjxwOeS0QovnvAxBNNAO/ X-Gm-Message-State: AOJu0YzA0SivgIUa6E+sRM3tB70rIkwH4w3iqHtCTYsWL8E/yf2BJwKW 6mkQJRqMhxaRkHQeKsZmnJoUUxwj+egAZL1/hCCLwKccP9uOpWIF X-Google-Smtp-Source: AGHT+IFEJRSyYDcqXxgJTNj++slLPETQqnGWVLmxL5nt0hFK4rS5XJCjEcJhkpC+q+6M7GET+9SLDg== X-Received: by 2002:a17:902:f54b:b0:1ff:56b8:2c1b with SMTP id d9443c01a7336-1ff574b0706mr176758005ad.60.1723015320269; Wed, 07 Aug 2024 00:22:00 -0700 (PDT) Received: from [192.168.255.10] ([43.132.141.24]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-1ff592ac8f4sm98957155ad.274.2024.08.07.00.21.57 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 07 Aug 2024 00:21:59 -0700 (PDT) Message-ID: Date: Wed, 7 Aug 2024 15:21:56 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v5 00/21] mm/zsmalloc: add zpdesc memory descriptor for zswap.zpool To: Sergey Senozhatsky , Yosry Ahmed , Matthew Wilcox Cc: Andrew Morton , alexs@kernel.org, Vitaly Wool , Miaohe Lin , linux-kernel@vger.kernel.org, linux-mm@kvack.org, minchan@kernel.org, david@redhat.com, 42.hyeyoo@gmail.com, nphamcs@gmail.com References: <20240806022143.3924396-1-alexs@kernel.org> <20240806022311.3924442-1-alexs@kernel.org> <20240806123213.2a747a8321bdf452b3307fa9@linux-foundation.org> <20240807051754.GA428000@google.com> Content-Language: en-US From: Alex Shi In-Reply-To: <20240807051754.GA428000@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 8/7/24 1:17 PM, Sergey Senozhatsky wrote: > On (24/08/06 12:34), Yosry Ahmed wrote: > [..] >>> So the sole reason for this work is as a part of the mem_desc >>> conversion. I'd like to hear from others who are to be involved in >>> that conversion, please - it this patchset something we should be >>> merging? >>> >> >> Matthew asked an important question here that needs to be answered by >> zsmalloc experts: >> https://lore.kernel.org/lkml/Zq0zucMFsOwATsAC@casper.infradead.org/ > > Iff "zsmalloc experts" include me: I was under impression that there was > a zsmalloc conversion plan otherwise this zpdesc effort is a little > confusing, and, frankly, it hasn't appeared to me that this is "my problem" > now. > >> Do you allocate a per-page struct zpdesc, and have each one pointing >> to a zspage? > > I'm not very knowledgeable when it comes to memdesc, excuse my > ignorance, and please feel free to educate me. > > So I guess if we have something > > struct zspage { > .. > struct zpdesc *first_desc; > .. > } > > and we "chain" zpdesc-s to form a zspage, and make each of them point to > a corresponding struct page (memdesc -> *page), then it'll resemble current > zsmalloc and should work for everyone? I also assume for zspdesc-s zsmalloc > will need to maintain a dedicated kmem_cache? Yes, it would be a better way moving to memdesc, and using kmem_cache for zpdesc-s seems workable. Thanks Alex