From nobody Sun Feb 8 20:17:38 2026 Received: from mail-m155101.qiye.163.com (mail-m155101.qiye.163.com [101.71.155.101]) (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 38BF714277 for ; Sun, 4 Feb 2024 08:34:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=101.71.155.101 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707035697; cv=none; b=p2NboSnbXsXFp7jNSu/iJptCihFfjvR+KwAh7w6S/tFgWx/yBfKkCCACpvOWMWSdY9XIijnDm0TQ3lGqn2KYZYYtZHp17jWngFIxU5bkvTx3S2btKVnMMe2MBoFXbgev8w2/pRB2F8NXdD/L8po+C2swjxZBELOoOYXD9K/HzEY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707035697; c=relaxed/simple; bh=52IuM5w4zXtuLhzfWQ+0wIQOBvpLw9tXlOp2CIEBv1E=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=dbB11rs5IvyeYH8tbTfMSoTivxTIilUFH7Y4UK5rCaEXW1wGFN/Ap+jhb73ecAT0GIDZEW0FAx++4FA+0jZiHEY03e1qjadbhMLTjpX12CxAG8c1AXAxc6AgobG2QRHKinGQQjzuq7YQqlft4C9Wcenu0UxyyCg7/eCgr/aW+WE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ustc.edu; spf=pass smtp.mailfrom=ustc.edu; arc=none smtp.client-ip=101.71.155.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=ustc.edu Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ustc.edu Received: from localhost.localdomain (unknown [111.206.94.146]) by smtp.qiye.163.com (Hmail) with ESMTPA id E6B9C7E011C; Sun, 4 Feb 2024 16:34:16 +0800 (CST) From: Chunsheng Luo To: gregkh@linuxfoundation.org Cc: rafael@kernel.org, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Chunsheng Luo Subject: [PATCH] meminfo: provide estimated per-node's available memory Date: Sun, 4 Feb 2024 03:34:14 -0500 Message-ID: <20240204083414.107799-1-luochunsheng@ustc.edu> X-Mailer: git-send-email 2.43.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFITzdXWS1ZQUlXWQ8JGhUIEh9ZQVkZS0pOVk0eGEJOSR5KH04eGVUTARMWGhIXJBQOD1 lXWRgSC1lBWUpKSlVJS01VQk9VSk9NWVdZFhoPEhUdFFlBWU9LSFVKTU9JTE5VSktLVUpCS0tZBg ++ X-HM-Tid: 0a8d7341047e03a2kunme6b9c7e011c X-HM-MType: 10 X-HM-Sender-Digest: e1kMHhlZQR0aFwgeV1kSHx4VD1lBWUc6PT46Hhw6GjMLHz8VH0wWAjw9 PCIKCwlVSlVKTEtMS0hOTU5MTENOVTMWGhIXVRcOFBgTDhUIEx4VHDsOCA8YVR4fDkVZV1kSC1lB WUpKSlVJS01VQk9VSk9NWVdZCAFZQU5IQks3Bg++ Content-Type: text/plain; charset="utf-8" The system offers an estimate of the per-node's available memory, in addition to the system's available memory provided by /proc/meminfo. like commit 34e431b0ae39("/proc/meminfo: provide estimated available memory"), it is more convenient to provide such an estimate in /sys/bus/node/devices/nodex/meminfo. If things change in the future, we only have to change it in one place. Shown below: /sys/bus/node/devices/node1/meminfo: Node 1 MemTotal: 4084480 kB Node 1 MemFree: 3348820 kB Node 1 MemAvailable: 3647972 kB Node 1 MemUsed: 735660 kB .... Link: https://github.com/numactl/numactl/issues/210 Signed-off-by: Chunsheng Luo Reviewed-by: Andi Kleen --- drivers/base/node.c | 4 ++++ include/linux/mm.h | 1 + mm/show_mem.c | 43 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 48 insertions(+) diff --git a/drivers/base/node.c b/drivers/base/node.c index 1c05640461dd..ba27f25d2b81 100644 --- a/drivers/base/node.c +++ b/drivers/base/node.c @@ -372,11 +372,13 @@ static ssize_t node_read_meminfo(struct device *dev, int len =3D 0; int nid =3D dev->id; struct pglist_data *pgdat =3D NODE_DATA(nid); + long available; struct sysinfo i; unsigned long sreclaimable, sunreclaimable; unsigned long swapcached =3D 0; =20 si_meminfo_node(&i, nid); + available =3D si_mem_node_available(nid); sreclaimable =3D node_page_state_pages(pgdat, NR_SLAB_RECLAIMABLE_B); sunreclaimable =3D node_page_state_pages(pgdat, NR_SLAB_UNRECLAIMABLE_B); #ifdef CONFIG_SWAP @@ -385,6 +387,7 @@ static ssize_t node_read_meminfo(struct device *dev, len =3D sysfs_emit_at(buf, len, "Node %d MemTotal: %8lu kB\n" "Node %d MemFree: %8lu kB\n" + "Node %d MemAvailable: %8lu kB\n" "Node %d MemUsed: %8lu kB\n" "Node %d SwapCached: %8lu kB\n" "Node %d Active: %8lu kB\n" @@ -397,6 +400,7 @@ static ssize_t node_read_meminfo(struct device *dev, "Node %d Mlocked: %8lu kB\n", nid, K(i.totalram), nid, K(i.freeram), + nid, K(available), nid, K(i.totalram - i.freeram), nid, K(swapcached), nid, K(node_page_state(pgdat, NR_ACTIVE_ANON) + diff --git a/include/linux/mm.h b/include/linux/mm.h index f5a97dec5169..3caef083fe5b 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -3202,6 +3202,7 @@ static inline void show_mem(void) extern long si_mem_available(void); extern void si_meminfo(struct sysinfo * val); extern void si_meminfo_node(struct sysinfo *val, int nid); +extern long si_mem_node_available(int nid); #ifdef __HAVE_ARCH_RESERVED_KERNEL_PAGES extern unsigned long arch_reserved_kernel_pages(void); #endif diff --git a/mm/show_mem.c b/mm/show_mem.c index 8dcfafbd283c..37d4c7212b06 100644 --- a/mm/show_mem.c +++ b/mm/show_mem.c @@ -86,6 +86,49 @@ void si_meminfo(struct sysinfo *val) EXPORT_SYMBOL(si_meminfo); =20 #ifdef CONFIG_NUMA +long si_mem_node_available(int nid) +{ + int zone_type; + long available; + unsigned long pagecache; + unsigned long wmark_low =3D 0; + unsigned long reclaimable; + pg_data_t *pgdat =3D NODE_DATA(nid); + + for (zone_type =3D 0; zone_type < MAX_NR_ZONES; zone_type++) + wmark_low +=3D low_wmark_pages((&pgdat->node_zones[zone_type])); + + /* + * Estimate the amount of memory available for userspace allocations, + * without causing swapping for mbind process. + */ + available =3D sum_zone_node_page_state(nid, NR_FREE_PAGES) - pgdat->total= reserve_pages; + + /* + * Not all the page cache can be freed, otherwise the system will + * start swapping or thrashing. Assume at least half of the page + * cache, or the low watermark worth of cache, needs to stay. + */ + pagecache =3D node_page_state(pgdat, NR_ACTIVE_FILE) + + node_page_state(pgdat, NR_INACTIVE_FILE); + pagecache -=3D min(pagecache / 2, wmark_low); + available +=3D pagecache; + + /* + * Part of the reclaimable slab and other kernel memory consists of + * items that are in use, and cannot be freed. Cap this estimate at the + * low watermark. + */ + reclaimable =3D node_page_state_pages(pgdat, NR_SLAB_RECLAIMABLE_B) + + node_page_state(pgdat, NR_KERNEL_MISC_RECLAIMABLE); + reclaimable -=3D min(reclaimable / 2, wmark_low); + available +=3D reclaimable; + + if (available < 0) + available =3D 0; + return available; +} + void si_meminfo_node(struct sysinfo *val, int nid) { int zone_type; /* needs to be signed */ --=20 2.43.0