From mboxrd@z Thu Jan  1 00:00:00 1970
From: miles.chen@mediatek.com (Miles Chen)
Date: Wed, 31 Oct 2018 16:47:17 +0800
Subject: [PATCH v3] mm/page_owner: use kvmalloc instead of kmalloc
In-Reply-To: <20181030081537.GV32673@dhcp22.suse.cz>
References: <1540790176-32339-1-git-send-email-miles.chen@mediatek.com>
 <20181029080708.GA32673@dhcp22.suse.cz>
 <20181029081706.GC32673@dhcp22.suse.cz>
 <1540862950.12374.40.camel@mtkswgap22>
 <20181030060601.GR32673@dhcp22.suse.cz>
 <1540882551.23278.12.camel@mtkswgap22>
 <20181030081537.GV32673@dhcp22.suse.cz>
Message-ID: <1540975637.10275.10.camel@mtkswgap22>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On Tue, 2018-10-30 at 09:15 +0100, Michal Hocko wrote:
> On Tue 30-10-18 14:55:51, Miles Chen wrote:
> [...]
> > It's a real problem when using page_owner.
> > I found this issue recently: I'm not able to read page_owner information
> > during a overnight test. (error: read failed: Out of memory). I replace
> > kmalloc() with vmalloc() and it worked well.
> 
> Is this with trimming the allocation to a single page and doing shorter
> than requested reads?


I printed out the allocate count on my device the request count is <=
4096. So I tested this scenario by trimming the count to from 4096 to
1024 bytes and it works fine. 

count = count > 1024? 1024: count;

It tested it on both 32bit and 64bit kernel.