From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-100.freemail.mail.aliyun.com (out30-100.freemail.mail.aliyun.com [115.124.30.100]) (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 3FCC731D372 for ; Tue, 30 Jun 2026 11:21:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.100 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782818488; cv=none; b=SZ5T2nGKd8qcewhhjMU/txXK32XV//OREBMWalIf6cZ9Jdok8XhlT729fAWzeExz5LSiU9tIRcQR49AK/Fl0c3EbIKm6647L3DBiRLLLcnsi7fIjbZyouTlKjcILULRYV78CUtTya+gkkUIPmZC9ZwAVp8y4dDxaYBdopBD7WjU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782818488; c=relaxed/simple; bh=U/MX0usEFQYDs3XEwoCmzSPFbPR0w9+MEWtMmkAJfrI=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=QbvfdsIiAZlzqy7B60hxUxOTy1D7pnBV8bDmkx+8TV4Lpo/l7i1Wst956NfkV5XaftoOZiFy83VnOV66jpEUxoWgmJT4tvZkiSx0vzYGRpl9KsrmOtF5DHc+cUXfz+D5dgMYMxkgnHntMtLkmC0BZMpCV5tZQI0hUIn3IOUbsZo= 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=usDdadxi; arc=none smtp.client-ip=115.124.30.100 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="usDdadxi" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1782818484; h=From:To:Subject:Date:Message-ID:MIME-Version:Content-Type; bh=Ljfnf+EHUqjOGTWLqk9h72HDHTyC4ixrumRdsjLJTBc=; b=usDdadxiPy4NzkTWiMxCwHKyHXSTNcJM8VEU/ubUY27ohqzHtPhOzUpXDWZoBfeB1Ig8fH6oyrcL6PQj+RzMFKhYUu8HLg8QxyUitbd3sWr6IWA2aSYU2sIN2pzCT0Sh4SvSIczexH3biO6A6U+b2peMO/BpVliwJ/rvkYNOADo= X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=maildocker-contentspam033032089153;MF=ying.huang@linux.alibaba.com;NM=1;PH=DS;RN=13;SR=0;TI=SMTPD_---0X6.LgeD_1782818452; Received: from DESKTOP-5N7EMDA(mailfrom:ying.huang@linux.alibaba.com fp:SMTPD_---0X6.LgeD_1782818452 cluster:ay36) by smtp.aliyun-inc.com; Tue, 30 Jun 2026 19:21:22 +0800 From: "Huang, Ying" To: Gregory Price Cc: Johannes Weiner , Andrew Morton , David Hildenbrand , Zi Yan , Matthew Brost , Joshua Hahn , Rakie Kim , Byungchul Park , Alistair Popple , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Neha Gholkar Subject: Re: [PATCH] mm: mempolicy: fix automatic numa balancing for shmem In-Reply-To: (Gregory Price's message of "Mon, 29 Jun 2026 13:59:41 -0400") References: <20260629163337.1264881-1-hannes@cmpxchg.org> Date: Tue, 30 Jun 2026 19:20:50 +0800 Message-ID: <87h5mkz33h.fsf@DESKTOP-5N7EMDA> User-Agent: Gnus/5.13 (Gnus v5.13) 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=ascii Gregory Price writes: [snip] > Demotions don't care about mempolicy, so opting shmem out of NUMA > balancing and mbind'ing on a tiered system is just full sadness. > > This is all just more evidence that demotion needs to be completely > redone, it's creating a mess of undefined behavior for memory placement. It's hard to respect mempolicy during demotion in the current implementation. Do you have any ideas on how to improve this? --- Best Regards, Huang, Ying