From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-130.freemail.mail.aliyun.com (out30-130.freemail.mail.aliyun.com [115.124.30.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1717C8BFF; Tue, 24 Dec 2024 23:48:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735084132; cv=none; b=HBBunho0gu03dnmYBYu/NOaF4V7E/3RDqMdAF2YX9mbKYFaJVOZpTZQVXVdyHafaSnPIrGQx2A84ZZqt4ZbWbXA/taljqtacoZMpzCrOCzHbk12oeH7ZXSNi5rqsuJZ0kIZoFqA9dRq+F/6Ne0aYV7SV6m5PXt78mHuCI8xukbE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1735084132; c=relaxed/simple; bh=h9jfdjju27KvlVZ6XfuVsuCs1r92celUHxGn2RMhSdk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=ibWtoORkUmsgTqNieV3TEJ1xIonYV48mKTUiImS1WLRhb4O9l4lKo273S8SxOrt8MDyqjh/KZc/dWa5GJ5cHBmV6ons2yHavMk5TObESVQIxXmN7WGFM9VU/Z5Yc5cuoI6aKXX46OfanZ678wNnsQkryKsHV50W1+gwkT13CZP4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=e/qjZZvI; arc=none smtp.client-ip=115.124.30.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="e/qjZZvI" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1735084120; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type; bh=IWOt90lynNL0xLBlX/5fzb0ZLmhgA/zMlV5D1Uv2jLM=; b=e/qjZZvIswuGE4wtdh0D93X6hWPY9ltPvHhJS9Ecg4Ue7oyfcfkQLj0w4RohmUqInf1eLZBV98RVY4RqOXq8bSa2vJoVXIbllYU6qqdm9xVVNEXpBpNy2nPv2kLx07Po7nPqCskSckk2Jeg7gCs7LMkKgyA/1k06NdARCHx7OKA= Received: from DESKTOP-5N7EMDA(mailfrom:ying.huang@linux.alibaba.com fp:SMTPD_---0WMD4lv7_1735084117 cluster:ay36) by smtp.aliyun-inc.com; Wed, 25 Dec 2024 07:48:38 +0800 From: "Huang, Ying" To: Gregory Price Cc: Hyeonggon Yoo , Joshua Hahn , kernel_team@skhynix.com, 42.hyeyoo@gmail.com, "rafael@kernel.org" , "lenb@kernel.org" , "gregkh@linuxfoundation.org" , "akpm@linux-foundation.org" , Honggyu Kim , Rakie Kim , "dan.j.williams@intel.com" , "Jonathan.Cameron@huawei.com" , "dave.jiang@intel.com" , "horen.chuang@linux.dev" , "hannes@cmpxchg.org" , "linux-mm@kvack.org" , "linux-kernel@vger.kernel.org" , "linux-acpi@vger.kernel.org" , "kernel-team@meta.com" Subject: Re: [External Mail] [RFC PATCH v2] Weighted interleave auto-tuning In-Reply-To: (Gregory Price's message of "Sun, 22 Dec 2024 12:03:22 -0500") References: <20241219191845.3506370-1-joshua.hahnjy@gmail.com> <3682b9cf-213c-497d-ab81-f70e1a785716@sk.com> <87r060i3nn.fsf@DESKTOP-5N7EMDA> User-Agent: Gnus/5.13 (Gnus v5.13) Date: Wed, 25 Dec 2024 07:48:36 +0800 Message-ID: <87ikr8abhn.fsf@DESKTOP-5N7EMDA> Precedence: bulk X-Mailing-List: linux-acpi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Gregory Price writes: > On Sun, Dec 22, 2024 at 03:21:32PM +0800, Huang, Ying wrote: >> Hyeonggon Yoo writes: >> >> > On this server, ideally weighted interleaving should be configured >> > within a socket (e.g. local NUMA node + local CXL node) because >> > weighted interleaving does not consider the bandwidth when accessed >> > from a remote socket. >> >> If multiple sockets are considered, what is the best behavior? >> >> The process may be cross-socket too. So, we will need to use >> set_mempolicy() to bind tasks to sockets firstly. Then, it may be >> better to use per-task weights. >> > > If we want to revisit this, we might be able to make task-local weights > work without a new syscall, but the use case was not clear enough which > is why it was soft-nak'd originally. Yes. That is doable. However, the challenge is lacking use cases. I guess that we can wait for more use cases? > vma-local weights are arguably more usable, but require the task to be > numa-aware and probably require a new mempolicy syscall because mbind > has no remaining arguments. > > recall my original testing results from stream: > https://lore.kernel.org/linux-mm/20240202170238.90004-1-gregory.price@memverge.com/ > > Stream Benchmark (vs DRAM, 1 Socket + 1 CXL Device) > Default interleave : -78% (slower than DRAM) > Global weighting : -6% to +4% (workload dependant) > Targeted weights : +2.5% to +4% (consistently better than DRAM) --- Best Regards, Huang, Ying