linux-kernel - Re: [PATCH 0/6] Shrinking DT memory usage

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 6 Oct 2017 19:24:42 -0400 (EDT)
From:   Nicolas Pitre <nicolas.pitre@...aro.org>
To:     Rob Herring <robh@...nel.org>
cc:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        Frank Rowand <frowand.list@...il.com>,
        Grant Likely <glikely@...retlab.ca>
Subject: Re: [PATCH 0/6] Shrinking DT memory usage

On Fri, 6 Oct 2017, Rob Herring wrote:

> On Fri, Oct 6, 2017 at 4:30 PM, Nicolas Pitre <nicolas.pitre@...aro.org> wrote:
> > On Thu, 5 Oct 2017, Rob Herring wrote:
> >
> >> On kernels with a minimal config and a RAM target in the 100s of KB, DT
> >> is quite a hog of runtime memory usage. How much is dependent on how many
> >> nodes and properties in the DT which have a corresponding struct device_node
> >> and struct property in the kernel. Just skipping disabled nodes saves a
> >> lot by not creating the device_nodes in the first place[1], but there's
> >> more low hanging fruit by making some of the fields in struct property and
> >> struct device_node optional. With the changes here, the memory usage goes
> >> from 17KB to under 8KB on QEMU's ARM virt machine which is a relatively
> >> small DT.
> >
> > My test case went from 118072 bytes ddown to 21548 bytes with this
> > series.
> 
> Did that include the changes for FDT skipping status=disabled and to
> stop storing the full path of every node? With those 2 alone you said
> it dropped to 25K.

No -- that's with those 6 patches only.

Adding the other 2 patches on top and it is down to 11732 bytes.


Nicolas