From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl1-f198.google.com (mail-pl1-f198.google.com [209.85.214.198]) by kanga.kvack.org (Postfix) with ESMTP id 0A09F6B0005 for ; Sun, 4 Nov 2018 19:50:08 -0500 (EST) Received: by mail-pl1-f198.google.com with SMTP id t10-v6so8524349plh.14 for ; Sun, 04 Nov 2018 16:50:07 -0800 (PST) Received: from mga12.intel.com (mga12.intel.com. [192.55.52.136]) by mx.google.com with ESMTPS id d24-v6si8131688plr.127.2018.11.04.16.50.06 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 04 Nov 2018 16:50:06 -0800 (PST) From: "Huang\, Ying" Subject: Re: [PATCH 1/2] mm: use kvzalloc for swap_info_struct allocation References: <37b60523-d085-71e9-fef9-80b90bfcef18@virtuozzo.com> Date: Mon, 05 Nov 2018 08:50:04 +0800 In-Reply-To: <37b60523-d085-71e9-fef9-80b90bfcef18@virtuozzo.com> (Vasily Averin's message of "Mon, 5 Nov 2018 01:13:04 +0300") Message-ID: <87wopsbb5v.fsf@yhuang-dev.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ascii Sender: owner-linux-mm@kvack.org List-ID: To: Vasily Averin Cc: linux-mm@kvack.org, Andrew Morton , linux-kernel@vger.kernel.org, Aaron Lu Vasily Averin writes: > commit a2468cc9bfdf ("swap: choose swap device according to numa node") > increased size of swap_info_struct up to 44 Kbytes, now it requires > 4th order page. Why swap_info_struct could be so large? Because MAX_NUMNODES could be thousands so that 'avail_lists' field could be tens KB? If so, I think it's fair to use kvzalloc(). Can you add one line comment? Because struct swap_info_struct is quite small in default configuration. Best Regards, Huang, Ying > Switch to kvzmalloc allows to avoid unexpected allocation failures. > > Signed-off-by: Vasily Averin > --- > mm/swapfile.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/mm/swapfile.c b/mm/swapfile.c > index 644f746e167a..8688ae65ef58 100644 > --- a/mm/swapfile.c > +++ b/mm/swapfile.c > @@ -2813,7 +2813,7 @@ static struct swap_info_struct *alloc_swap_info(void) > unsigned int type; > int i; > > - p = kzalloc(sizeof(*p), GFP_KERNEL); > + p = kvzalloc(sizeof(*p), GFP_KERNEL); > if (!p) > return ERR_PTR(-ENOMEM); > > @@ -2824,7 +2824,7 @@ static struct swap_info_struct *alloc_swap_info(void) > } > if (type >= MAX_SWAPFILES) { > spin_unlock(&swap_lock); > - kfree(p); > + kvfree(p); > return ERR_PTR(-EPERM); > } > if (type >= nr_swapfiles) { > @@ -2838,7 +2838,7 @@ static struct swap_info_struct *alloc_swap_info(void) > smp_wmb(); > nr_swapfiles++; > } else { > - kfree(p); > + kvfree(p); > p = swap_info[type]; > /* > * Do not memset this entry: a racing procfs swap_next()