From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.140.110.172 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793789495; b=4+AV6Zpm08qLULwfLZ6jyn4P5+1T+AJjO4QBPtHV1DTGlgS7e6NqqlZMxpYum2555LEY IKWC8y637d/86IdkxUeC6YFZpfX68FbNn5hAhxr0GqzBYaumd2thwyuNixOpf5Vn3PP8i /s23qFOlZXKN2GACOVC+MiVOHQJQYwFPam6i0DvdOqPUoqkclY2F7lmmj6a2KIYpLAaFb rQbuyoGPHu9RE6TB34xNc4eCwNbTxpX5F1qKWjbhKa6XIqEPvExBnN6uxhuUky8l5StZD fJkjFbz+EAB6qWa/wPv1/Z3FFxLmG6Z1I9dsOy56Pta+m1r6kGlEyMKvqkEjPha9lZA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793789495; h=DMARC-Filter:Received:Received:DKIM-Signature:Message-ID:Date: MIME-Version:User-Agent:Subject:To:References:Content-Language:From: In-Reply-To:Content-Type:Content-Transfer-Encoding; bh=HXDgHwIg8m4DwtOhwv+ZFMPIRE8BcYqQdrGKa3M5Pbs=; b=wNwN/YInuDTu/mZdqk2RK2AXFDrRCcVD+zWkQPbjcS4doVUrODb3ABY4sUua7/HBK852 49lvaIOVmR7RRf3JpDvsCeR6uU2B1knqHplzjUcfNTw0v/DqDoB9pZobg3asRvt5jOl+l Sq1xBBZ8mA/Rtn4zErfCrJE7kGAlvANhp0+xmJEV3HxSXbJI/CSmA0EINUhcHrnpYWfO+ 3ud8kEWsHmsI+eXnxDcAvS0TqE4fXHVqklTWf/2G5uI6/gnvhOkMcNKxljwn3oVhKRahH aJWP3GCopuN75mAcf8PbyYYErbOWjq8ZuNOc31JW3m8IO/ZD/TZZa1iQzFhJgogahYg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=GHFQHyoD; arc=none smtp.remote-ip=217.140.110.172 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 3DABF606A326 for ; Wed, 4 Nov 2026 10:51:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 3DABF606A326 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=arm.com header.i=@arm.com header.a=rsa-sha256 header.s=foss header.b=GHFQHyoD Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 410352247; Wed, 4 Nov 2026 02:51:31 -0800 (PST) Received: from [10.2.212.8] (e134344.arm.com [10.2.212.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8D4D63F628; Wed, 4 Nov 2026 02:51:32 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1793789494; bh=aDq3A0xHGBXoAmwsG8E6qJPjO2aDOH/ROmFDF348ug4=; h=Date:Subject:To:References:From:In-Reply-To:From; b=GHFQHyoDS3/7ZGobLiPRAROn6IMSSLdC5HWD+VfwMHO89GcuouzLbz7SYD1ktTpKf w2V/XqQy7f25Se5LdBQUWjjwCK75sf23IO5xbKoqj7Y0IZoeAklgHshi/w2gf4lIHn zBPgaWfM1kTR1P6/DHhrTLd8/Q2MGJtS4W1YzVQs= Message-ID: <8a543030-d0c1-416f-8747-6cd599ad6a90@arm.com> Date: Wed, 4 Nov 2026 10:51:30 +0000 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] fs/resctrl: Allocate the RMID array with kvzalloc To: Jinjie Ruan , tony.luck@intel.com, reinette.chatre@intel.com, Dave.Martin@arm.com, james.morse@arm.com, babu.moger@amd.com, bp@alien8.de, tan.shaopeng@fujitsu.com, x86@kernel.org, linux-kernel@vger.kernel.org References: <20261104102004.609259-1-ruanjinjie@huawei.com> Content-Language: en-US From: Ben Horgan In-Reply-To: <20261104102004.609259-1-ruanjinjie@huawei.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Jinjie, On 04/11/2026 10:20, Jinjie Ruan wrote: > setup_rmid_lru_list() sizes rmid_ptrs[] by the whole RMID index space. > On x86 the index is the RMID, so the array stays small. On MPAM the > index space is the product of the PARTID and PMG ranges, and with a > large range the array is megabytes in size. > > kzalloc() needs a high-order page allocation for it, which fails once > memory is fragmented, and a size above KMALLOC_MAX_SIZE always fails. > resctrl then fails to mount. > > Use kvzalloc(), which falls back to vmalloc(). Yep, I ran into this too when experimenting with large PARTID counts on the FVP model. I have the same patch here [1] and plan to repost soon with some more related kmalloc to kvmalloc changes. [1] https://lore.kernel.org/lkml/20260911160608.1091121-1-ben.horgan@arm.com/ Thanks, Ben > > Fixes: 6791e0ea3071 ("x86/resctrl: Access per-rmid structures by index") > Signed-off-by: Jinjie Ruan > Cc: # 7.1.x > Cc: Tony Luck > Cc: Reinette Chatre > Cc: Dave Martin > Cc: James Morse > Cc: Babu Moger > --- > fs/resctrl/monitor.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/fs/resctrl/monitor.c b/fs/resctrl/monitor.c > index f69dbf66f42e..7713aa5d3996 100644 > --- a/fs/resctrl/monitor.c > +++ b/fs/resctrl/monitor.c > @@ -1029,7 +1029,7 @@ int setup_rmid_lru_list(void) > return 0; > > idx_limit = resctrl_arch_system_num_rmid_idx(); > - rmid_ptrs = kzalloc_objs(struct rmid_entry, idx_limit); > + rmid_ptrs = kvzalloc_objs(struct rmid_entry, idx_limit); > if (!rmid_ptrs) > return -ENOMEM; > > @@ -1125,7 +1125,7 @@ void free_rmid_lru_list(void) > return; > > mutex_lock(&rdtgroup_mutex); > - kfree(rmid_ptrs); > + kvfree(rmid_ptrs); > rmid_ptrs = NULL; > mutex_unlock(&rdtgroup_mutex); > }