From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-181.mta1.migadu.com (out-181.mta1.migadu.com [95.215.58.181]) (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 135FBF9DA for ; Thu, 22 May 2025 02:32:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.181 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747881126; cv=none; b=HJChCpXRSuWEgz8bVEeLJN6Lws5J1xDIcMbPZSIQTmK1tCsdnMBg3wYHtu2zukMPlXjvtwUgacHpj9YoMIR7vM0kp4mZoQxbo67o+eMjGJaKSyCNJ1tMY4iXDU+tBN1YSvxWDY5DhOZnh2ODQaLVLMA9BoijJTbMx6Dw75GsNI0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747881126; c=relaxed/simple; bh=CIkfuXr5e/FFnQf8w7cXy456Pqrq9wN5w94SM65gMCM=; h=Content-Type:Mime-Version:Subject:From:In-Reply-To:Date:Cc: Message-Id:References:To; b=odgbCzt07m855Z7mQ4H24phKFSDGhv+pPXwpkS7TE29zFnsW6f3LLmU3JlVl37bxR72TSr2ySrfaGIXgYJFc8LImWHQCWp0gkb/Rv4QVNUr0fnSCctjdKn6szNr+bZM6CgNgs/YyD6O/5StQztnLEXdyv7idPaIIhQ4WMg88oTY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=XorGxnXs; arc=none smtp.client-ip=95.215.58.181 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="XorGxnXs" Content-Type: text/plain; charset=us-ascii DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1747881120; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=v7OyzNFi4koovf7Ot55c4ptctb/+0JCIucwjXRDLPVY=; b=XorGxnXsae3VA5C2XCc0b1ahJ4y3yZPrGL8iFM61ZfF/bFE72dsoWm1KBWgv8HcBWbInlm Tc35CcCFHdTz7gf3QP37s+aiEutg8fLTRFzwXKgRgckoYYwJ0TnjCDKVEzb4G0cmVdp+ZQ zncFIK9i1r3a1eelRhzVGRbTthLmg2Y= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3826.500.181.1.5\)) Subject: Re: [PATCH RFC 27/28] mm: memcontrol: eliminate the problem of dying memory cgroup for LRU folios X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Muchun Song In-Reply-To: Date: Thu, 22 May 2025 10:31:20 +0800 Cc: Muchun Song , hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, akpm@linux-foundation.org, david@fromorbit.com, zhengqi.arch@bytedance.com, yosry.ahmed@linux.dev, nphamcs@gmail.com, chengming.zhou@linux.dev, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, linux-mm@kvack.org, hamzamahfooz@linux.microsoft.com, apais@linux.microsoft.com Content-Transfer-Encoding: 7bit Message-Id: <3782D28E-B0F0-4CC7-98A6-27E443A92730@linux.dev> References: <20250415024532.26632-1-songmuchun@bytedance.com> <20250415024532.26632-28-songmuchun@bytedance.com> To: Harry Yoo X-Migadu-Flow: FLOW_OUT > On May 20, 2025, at 19:27, Harry Yoo wrote: > > On Tue, Apr 15, 2025 at 10:45:31AM +0800, Muchun Song wrote: >> Pagecache pages are charged at allocation time and hold a reference >> to the original memory cgroup until reclaimed. Depending on memory >> pressure, page sharing patterns between different cgroups and cgroup >> creation/destruction rates, many dying memory cgroups can be pinned >> by pagecache pages, reducing page reclaim efficiency and wasting >> memory. Converting LRU folios and most other raw memory cgroup pins >> to the object cgroup direction can fix this long-living problem. >> >> Finally, folio->memcg_data of LRU folios and kmem folios will always >> point to an object cgroup pointer. The folio->memcg_data of slab >> folios will point to an vector of object cgroups. >> >> Signed-off-by: Muchun Song >> --- >> include/linux/memcontrol.h | 78 +++++-------- >> mm/huge_memory.c | 33 ++++++ >> mm/memcontrol-v1.c | 15 ++- >> mm/memcontrol.c | 228 +++++++++++++++++++++++++------------ >> 4 files changed, 222 insertions(+), 132 deletions(-) > > [...] > >> +static void lruvec_reparent_lru(struct lruvec *src, struct lruvec *dst, >> + enum lru_list lru) >> +{ >> + int zid; >> + struct mem_cgroup_per_node *mz_src, *mz_dst; >> + >> + mz_src = container_of(src, struct mem_cgroup_per_node, lruvec); >> + mz_dst = container_of(dst, struct mem_cgroup_per_node, lruvec); >> + >> + if (lru != LRU_UNEVICTABLE) >> + list_splice_tail_init(&src->lists[lru], &dst->lists[lru]); >> + >> + for (zid = 0; zid < MAX_NR_ZONES; zid++) { >> + mz_dst->lru_zone_size[zid][lru] += mz_src->lru_zone_size[zid][lru]; >> + mz_src->lru_zone_size[zid][lru] = 0; >> + } >> +} > > I think this function should also update memcg and lruvec stats of > parent memcg? Or is it intentional? Hi Harry, No. Do not need. Because the statistics are accounted hierarchically. Thanks. > > -- > Cheers, > Harry / Hyeonggon