From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-177.mta0.migadu.com (out-177.mta0.migadu.com [91.218.175.177]) (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 A678A28751B for ; Mon, 9 Mar 2026 03:31:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773027072; cv=none; b=eS398C1ope/AuWqxIORjbRCKbHpHhtldHv+CG8RjQaFhmRcf+FbLYG6b5IjEkx2k2vmqIhydOCu15/lhwbyqOMg0Kk60BFa+wILvn2vSZh6A7vK19UttOOrfB1/8SqXenr1qIAeoqAgje5WvcquGnkWv3CTDr/ucQgmHYlNHpiA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773027072; c=relaxed/simple; bh=Cq7pOWkgy5Xl5CZLed48itED/PWHe5kSVrGncmLnpYE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=tdWDnxEx/xHwJDDDPf9u8Uz1hPsxUEqAegtnoXpKIhPm+rQi8giPblbgoEvfR8FFSxJ7pHNn9kt+m9K54OQcw4A6/A6t9P0AxUVdJ5ep71lvELXsydUnT2wMR/4JlB2ESXG0nsJsundzz/y+Puffte3ukM+LtSNuM6Rhx92n50U= 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=I1WPgWyD; arc=none smtp.client-ip=91.218.175.177 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="I1WPgWyD" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1773027058; 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=MGRzB9NB7RnJy1AFfNjO4UdJlA1IIFldq9U5XbxXvLE=; b=I1WPgWyDe1PpSkWi58Zt5V7YwT8hbeXPtsYCQU2giIVSqguWg0dr5EDnvQX68WY0JDajo9 tmo9uHiI36ZHcYV17iiu58tmXfGiZvnz/M6Mgeww97WrWDnV7hmN4VjOCNQ1+WVMItxj8U hawDYa8Qn46vurq+8oinWUsny/0xQRQ= Date: Sun, 8 Mar 2026 20:30:47 -0700 Precedence: bulk X-Mailing-List: virtualization@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH v2] mm/mempolicy: track page allocations per mempolicy To: Usama Arif Cc: linux-mm@kvack.org, akpm@linux-foundation.org, mhocko@suse.com, vbabka@suse.cz, apopple@nvidia.com, axelrasmussen@google.com, byungchul@sk.com, cgroups@vger.kernel.org, david@kernel.org, eperezma@redhat.com, gourry@gourry.net, jasowang@redhat.com, hannes@cmpxchg.org, joshua.hahnjy@gmail.com, Liam.Howlett@oracle.com, linux-kernel@vger.kernel.org, lorenzo.stoakes@oracle.com, matthew.brost@intel.com, mst@redhat.com, rppt@kernel.org, muchun.song@linux.dev, zhengqi.arch@bytedance.com, rakie.kim@sk.com, roman.gushchin@linux.dev, shakeel.butt@linux.dev, surenb@google.com, virtualization@lists.linux.dev, weixugc@google.com, xuanzhuo@linux.alibaba.com, ying.huang@linux.alibaba.com, yuanchu@google.com, ziy@nvidia.com, kernel-team@meta.com References: <20260308192438.1363382-1-usama.arif@linux.dev> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: "JP Kobryn (Meta)" In-Reply-To: <20260308192438.1363382-1-usama.arif@linux.dev> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Migadu-Flow: FLOW_OUT On 3/8/26 12:24 PM, Usama Arif wrote: > On Fri, 6 Mar 2026 20:55:20 -0800 "JP Kobryn (Meta)" wrote: [...] >> +static void mpol_count_numa_alloc(struct mempolicy *pol, int intended_nid, >> + struct page *page, unsigned int order) >> +{ >> + int actual_nid = page_to_nid(page); >> + long nr_pages = 1L << order; >> + enum node_stat_item hit_idx; >> + struct mem_cgroup *memcg; >> + struct lruvec *lruvec; >> + bool is_hit; >> + >> + if (!root_mem_cgroup || mem_cgroup_disabled()) >> + return; > > Hello JP! > > The stats are exposed via /proc/vmstat and are guarded by CONFIG_NUMA, not > CONFIG_MEMCG. Early returning overhere would make it inaccuate. Does > it make sense to use mod_node_page_state if memcg is not available, > so that these global counters work regardless of cgroup configuration. > Good call. I can instead do: if (!mem_cgroup_disabled() && root_mem_cgroup) { struct mem_cgroup *memcg; struct lruvec *lruvec; /* use lruvec for updating stats */ } else { /* use node for updating stats */ } This should also take care of the bot warning on mem_cgroup_from_task() not being available.