From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id F2949C54E58 for ; Mon, 18 Mar 2024 13:33:49 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 818DB6B0088; Mon, 18 Mar 2024 09:33:49 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 77A9B6B008A; Mon, 18 Mar 2024 09:33:49 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5F4A46B008C; Mon, 18 Mar 2024 09:33:49 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 4B7996B0088 for ; Mon, 18 Mar 2024 09:33:49 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by 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smtp.mailfrom=honggyu.kim@sk.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1710768827; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=ESbYdQ/MGuMB0zVBUU0CqgphShNmbFR50Mxhe/T8jf4=; b=55Z32/e6zLWB4IKlfslnOn+z5/f6NmZ49HCMb7DLo2UBFHmceKMIoE3cLrrVm/iKrqizoD vtRm9Ywv37MMRPYKn55DjMeE25NBY01iQ+7qn+yqZhpJFdO2DlGAnFgZzsrKPH/+Unc3kR y3+9YX7OWuFISRYckkWUVQEjr87hzPw= X-AuditID: a67dfc5b-d85ff70000001748-7a-65f842b48e22 From: Honggyu Kim To: SeongJae Park Cc: Honggyu Kim , damon@lists.linux.dev, linux-mm@kvack.org, akpm@linux-foundation.org, apopple@nvidia.com, baolin.wang@linux.alibaba.com, dave.jiang@intel.com, hyeongtak.ji@sk.com, kernel_team@skhynix.com, linmiaohe@huawei.com, linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, mathieu.desnoyers@efficios.com, mhiramat@kernel.org, rakie.kim@sk.com, rostedt@goodmis.org, surenb@google.com, yangx.jy@fujitsu.com, ying.huang@intel.com, ziy@nvidia.com, 42.hyeyoo@gmail.com Subject: Re: [RFC PATCH v2 0/7] DAMON based 2-tier memory management for CXL memory Date: Mon, 18 Mar 2024 22:33:34 +0900 Message-ID: <20240318133338.2135-1-honggyu.kim@sk.com> X-Mailer: git-send-email 2.43.0.windows.1 In-Reply-To: <20240317191358.97578-1-sj@kernel.org> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFprHIsWRmVeSWpSXmKPExsXC9ZZnke4Wpx+pBs+6lS0m9hhYzFm/hs1i 140Qi/97jzFaPPn/m9XixM1GNovO70tZLC7vmsNmcW/Nf1aLI+vPslhsPnuG2WLxcjWLfR0P mCwOf33DZDH50gI2ixdTzjBanJw1mcVi9tF77A5CHktPv2Hz2NAEJHbOusvu0bLvFrvHgk2l Hi1H3rJ6LN7zkslj06pONo9Nnyaxe5yY8ZvFY+dDS48Xm2cyevQ2v2Pz+LxJLoAvissmJTUn syy1SN8ugStjxcu3zAVdEhX9J1ezNDBOF+pi5OSQEDCRWLf8NhuM/fBbNzuIzSagJnHl5SQm EFtEQFHi3OOLrF2MXBzMAgtZJHq/bwBLCAsES8w9+5+xi5GDg0VAVeLGLl6QMK+AmcT+M8cZ 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 84nqEbzY I5PIZ7Fi0slAu3KYhl69Alo6aWYs8XQ2XZkq085+fzCCrGl495LLPoJtDQ76Ll3yJSzrYo0Zcy2zdhRllBk9u6qGPt3/tbPmO5rID8czdnw3m5sxWX8RS/qLYO70XdwAf4+21X0nvA3KgknCSZpvEASvk7QqPGO79BRl0 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: Hi SeongJae, On Sun, 17 Mar 2024 12:13:57 -0700 SeongJae Park wrote: > On Sun, 17 Mar 2024 08:31:44 -0700 SeongJae Park wrote: > > > Hi Honggyu, > > > > On Sun, 17 Mar 2024 17:36:29 +0900 Honggyu Kim wrote: > > > > > Hi SeongJae, > > > > > > Thanks for the confirmation. I have a few comments on young filter so > > > please read the inline comments again. > > > > > > On Wed, 12 Mar 2024 08:53:00 -0800 SeongJae Park wrote: > > > > Hi Honggyu, > [...] > > > Thanks. I see that it works fine, but I would like to have more > > > discussion about "young" filter. What I think about filter is that if I > > > apply "young" filter "true" for demotion, then the action applies only > > > for "young" pages, but the current implementation works opposite. > > > > > > I understand the function name of internal implementation is > > > "damos_pa_filter_out" so the basic action is filtering out, but the > > > cgroup filter works in the opposite way for now. > > > > Does memcg filter works in the opposite way? I don't think so because > > __damos_pa_filter_out() sets 'matches' as 'true' only if the the given folio is > > contained in the given memcg. 'young' filter also simply sets 'matches' as > > 'true' only if the given folio is young. > > > > If it works in the opposite way, it's a bug that need to be fixed. Please let > > me know if I'm missing something. > > I just read the DAMOS filters part of the documentation for DAMON sysfs > interface again. I believe it is explaining the meaning of 'matching' as I > intended to, as below: > > You can write ``Y`` or ``N`` to ``matching`` file to filter out pages that does > or does not match to the type, respectively. Then, the scheme's action will > not be applied to the pages that specified to be filtered out. > > But, I found the following example for memcg filter is wrong, as below: > > For example, below restricts a DAMOS action to be applied to only non-anonymous > pages of all memory cgroups except ``/having_care_already``.:: > > # echo 2 > nr_filters > # # filter out anonymous pages > echo anon > 0/type > echo Y > 0/matching > # # further filter out all cgroups except one at '/having_care_already' > echo memcg > 1/type > echo /having_care_already > 1/memcg_path > echo N > 1/matching > > Specifically, the last line of the commands should write 'Y' instead of 'N' to > do what explained. Without the fix, the action will be applied to only > non-anonymous pages of 'having_care_already' memcg. This is definitely wrong. > I will fix this soon. I'm unsure if this is what made you to believe memcg > DAMOS filter is working in the opposite way, though. I got confused not because of this. I just think it again that this user interface is better to be more intuitive as I mentioned in the previous thread. Thanks, Honggyu > > Thanks, > SJ > > [...]