From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pl1-f173.google.com (mail-pl1-f173.google.com [209.85.214.173]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 60CC51D545 for ; Thu, 15 Aug 2024 03:13:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.173 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723691602; cv=none; b=D7QPMtpEs8+/Gm+pXmzGhqZgDRmylhuJoB5jp0ArRWa8XEJPfZxzJiNxmzc4//+k7mJ5RwpCb8M4Lm2SSUTdqbECYsOpLXNo7LLraf7hdBWKovAKMK0z1ipBw4ZBTuacZqpspAeB6ShDlt1YoaJ1CSRb/vWxi6UYswouvsmSH4g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723691602; c=relaxed/simple; bh=nMMaWQiB0qYc73Kc9ZbapW7A2CkNeaOPs6WVx9G/B2g=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=o/eQvdvf6Inow+14vU+UyAcQMo5lHQWCcCViamWyu9QvJ5XpayhM2zTRNzEsarmGC9eDj4YX3lNj3uc96uwfq3EkaJSKuEuTRrdAHtchpP61whXMTZFQ3L3Os7uIuUx6Q8ax0wGiPUJcUs5hdKMT6glNJDE4K3VLoRj/t/5A9kY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org; spf=pass smtp.mailfrom=chromium.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b=ff8gZrmF; arc=none smtp.client-ip=209.85.214.173 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=chromium.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=chromium.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="ff8gZrmF" Received: by mail-pl1-f173.google.com with SMTP id d9443c01a7336-1fd640a6454so5820195ad.3 for ; Wed, 14 Aug 2024 20:13:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1723691601; x=1724296401; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=/2QRNR8+6EF7fidSTwruEnZbFCDgCCEDKWmftPIjM40=; b=ff8gZrmF4/edUZCeSoahtrh+G+e/Yv3gxAHzfH5hBV4qxFMpdJzgT2Ue+k5PoL8W8n 9V6VJVVTY5VwJp6+GOtWiPyqR0Zj2MbDO7CP7dptNTRIyiGE7gLZ5DGd0M6G3TJ456XX qJcj+OKgfhrAs0hTRhMNUQ1puG03zKVT22qDY= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723691601; x=1724296401; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=/2QRNR8+6EF7fidSTwruEnZbFCDgCCEDKWmftPIjM40=; b=S3KF1f6KpbQZZQ8vMUv6nKFpYmlepW4oDo4++nWI3q42QbSsmNyP4kHeCorduTSDuA FKBgcEzdREuhh0BT4jxuHYxLqX0cw4imuYacDPNlf0/F9nXoVTQcfocS9xAKuxSkPOx/ ivKGiMs+yq+8kXV8sNC/qd/1kuj5gAlGv6hcm0jhjujs2TSKZSssonmO6kWKn4wzbsAT OQ8XEhsUSYlEmncYT7bU+THoOsYtuBz0GA/LkZV+h9TUxJFuhG0FsZT0BIXBoqwJTlUo xOXohQ2ApDlL9JuKcvQkjaEOqUbXWkyOMcLGnGM/VInnjxWxOqUqHsWr6NT3V+wTZQlR eSyw== X-Forwarded-Encrypted: i=1; AJvYcCX1f+ZS7RlYiT9fLtwAExJMUADBvglJ/6CMT2OiwIs+CdzD07zAr4Xe24/1Zg3OzJ6C7ywa6a+U4rcmfAc=@vger.kernel.org X-Gm-Message-State: AOJu0Yz0Y2rkvmJUANIXaMcwsmw3PJqI/KhmV89ge9xgFIAoEt63chyr 2IgUiDOUeSTOkGdo96/vyPyFF/6OFmjrp9tKp72De16UAkoHadzVex6VTpKSAA== X-Google-Smtp-Source: AGHT+IFcE+QAUw1Xb2q5oNbVpZ6CwP5UBZo74femXozM7V0Ikea9OYg6dkTadOCjjUnRZ5fms91pcg== X-Received: by 2002:a17:903:35cf:b0:1fd:91b1:7883 with SMTP id d9443c01a7336-201d63abef6mr60223675ad.14.1723691600724; Wed, 14 Aug 2024 20:13:20 -0700 (PDT) Received: from google.com ([2401:fa00:8f:203:f7dc:2307:3c4b:963e]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-201f03a565bsm3116565ad.263.2024.08.14.20.13.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Aug 2024 20:13:20 -0700 (PDT) Date: Thu, 15 Aug 2024 12:13:14 +0900 From: Sergey Senozhatsky To: Alex Shi Cc: Matthew Wilcox , Sergey Senozhatsky , Yosry Ahmed , 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 Subject: Re: [PATCH v5 00/21] mm/zsmalloc: add zpdesc memory descriptor for zswap.zpool Message-ID: <20240815031314.GA12106@google.com> References: <20240806022143.3924396-1-alexs@kernel.org> <20240806022311.3924442-1-alexs@kernel.org> <20240806123213.2a747a8321bdf452b3307fa9@linux-foundation.org> <20240807051754.GA428000@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On (24/08/09 10:32), Alex Shi wrote: [..] > >> 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? > > Right, we could do that. Each memdesc has to be a multiple of 16 bytes, > > sp we'd be doing something like allocating 32 bytes for each page. > > Is there really 32 bytes of information that we want to store for > > each page? Or could we store all of the information in (a somewhat > > larger) zspage? Assuming we allocate 3 pages per zspage, if we allocate > > an extra 64 bytes in the zspage, we've saved 32 bytes per zspage. > > Thanks for the suggestions! Yes, it's a good direction we could try after this > patchset. Alex, may I ask what exactly you will "try"?