From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pg1-f176.google.com (mail-pg1-f176.google.com [209.85.215.176]) (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 10DB97346C for ; Mon, 24 Jun 2024 08:56:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.176 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719219406; cv=none; b=L2ZnOe9Vld+WRlmkMgp4E7garwN1xeKQSDAt7oT//YQNUJjIIBXaWq5mL406tz29swL0vz5zj6bB1jWFrfplplP54FzTZSRgJKdJnL8Mfl8ATKHabhTtdd9R/NIdG5uL/2RfkFmfG0mSAbe0nzN5FB6NMqdx5Ul3v/X7e5G122c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1719219406; c=relaxed/simple; bh=60jgSJ9BsP2kpjwq4csRJWDIIPPwj35/L6vDezVPoxE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=TAD4JjYOs/MAU2sZAMr44RWbkR6U58NAO8DkgeVCgePmRb2GFaIeFrEFN7X+Rm3KnT7TmAq3eDjTxiB7gCUI33UiLqxVXFcom0+1s0NZOcqhCsWlYTl63HJo8Ew7a5xNs5FL5lQXhgggGjOEOnyqAtrqJLxIRmogJxe2J5r/o48= 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=NIlm3K+p; arc=none smtp.client-ip=209.85.215.176 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="NIlm3K+p" Received: by mail-pg1-f176.google.com with SMTP id 41be03b00d2f7-7178727da84so1602977a12.0 for ; Mon, 24 Jun 2024 01:56:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; t=1719219404; x=1719824204; 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=vfhjqO2J81Ssb/Fuz1ky6uYbmEEWMBrkgz3wOJNpA9M=; b=NIlm3K+pzORHUe9l6BwvSACfmcVH+ETinoVmZpIIXh8GFbToUyF4UGFDERi1mg4V+O 5Tcj4b0eSdACEvPUq7ySlnNbRUnWdKN4dRUf/mCt+oEUA1abW8aBIsdey4CdmB1vszlO Aa4eLADdgFZKnqAGVrFJPS7lHduO+5/9XHzIM= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1719219404; x=1719824204; 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=vfhjqO2J81Ssb/Fuz1ky6uYbmEEWMBrkgz3wOJNpA9M=; b=loXRo7h/zm8b0Bw1yompts02w3T4IrDtz9qaF8uE2BAXssAQPkGKsiLGI/bS6DvT1V S21/cZ/zmj5e7WFJ+CrgqIK+gQH9/cQa11SJnphGp0XvWbt4pQzDF6s9H7oNn576mamK GtEAsUUEpdQZ93Mz7pIDfBgqcpaH0FiXCBXt+JjUgRB2I7Z11/+svu+Nx/UMkj65ShE0 k2jMo/rmr8BTiAjRIbISqa8y0cm3h/aHIt0icGzMgK1m5Ahczr5n1xLHnHgnqVNaL3rT 1jg9t/2xSVc2MwMMRKbQbLWdn1JOYAZoq9VozQqlJVKiowqdTyt7Xa2v6cg8Arh4HKkZ 5rCg== X-Forwarded-Encrypted: i=1; AJvYcCW216Fc+7x5bMGGJ894PSPgcpggmohvwsI131JGRKQOOaWyJXtKqclPPsW8cMjI68wYj8/bNtRTiZ5Ntv7NNIJxOO5JC4WNbJ/3pwlK X-Gm-Message-State: AOJu0YzjGedHKHJjz7o5ceczwpo0x3f0k7U8QvnrSQRs3wtUBuKmAib2 zPKUSbaz4KD8vzneZ/rZFZPaaFHfp6Oh6ZJ08FgnOxuee/wUj3J034L755G82A== X-Google-Smtp-Source: AGHT+IGOeL/QpfdM2r7m71ruASfasUfxopdj8Y8nJxGoGfAwF6tdeiBa/gyu/JEFhpZfPCnU8+m2MQ== X-Received: by 2002:a17:90a:9af:b0:2c7:e24d:f688 with SMTP id 98e67ed59e1d1-2c8504c7bc5mr3043128a91.7.1719219404223; Mon, 24 Jun 2024 01:56:44 -0700 (PDT) Received: from google.com ([2401:fa00:8f:203:4e6:bef0:f574:7d51]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-2c7e64a1300sm8214557a91.48.2024.06.24.01.56.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Jun 2024 01:56:43 -0700 (PDT) Date: Mon, 24 Jun 2024 17:56:38 +0900 From: Sergey Senozhatsky To: Andrew Morton , Chengming Zhou Cc: Minchan Kim , Sergey Senozhatsky , Johannes Weiner , Yosry Ahmed , Nhat Pham , Yu Zhao , Takero Funaki , Chengming Zhou , Dan Carpenter , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 1/2] mm/zsmalloc: change back to per-size_class lock Message-ID: <20240624085638.GB3130923@google.com> References: <20240621-zsmalloc-lock-mm-everything-v2-0-d30e9cd2b793@linux.dev> <20240621-zsmalloc-lock-mm-everything-v2-1-d30e9cd2b793@linux.dev> 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: <20240621-zsmalloc-lock-mm-everything-v2-1-d30e9cd2b793@linux.dev> On (24/06/21 15:15), Chengming Zhou wrote: > This patch is almost the revert of the commit c0547d0b6a4b ("zsmalloc: > consolidate zs_pool's migrate_lock and size_class's locks"), which > changed to use a global pool->lock instead of per-size_class lock and > pool->migrate_lock, was preparation for suppporting reclaim in zsmalloc. > Then reclaim in zsmalloc had been dropped in favor of LRU reclaim in > zswap. > > In theory, per-size_class is more fine-grained than the pool->lock, > since a pool can have many size_classes. As for the additional > pool->migrate_lock, only free() and map() need to grab it to access > stable handle to get zspage, and only in read lock mode. > > Signed-off-by: Chengming Zhou Reviewed-by: Sergey Senozhatsky